National Storage Affiliates Trust Annual report pursuant to Section 13 and 15(d)

Annual report pursuant to Section 13 and 15(d)

DEBT FINANCING - Narrative (Details)

DEBT FINANCING - Narrative (Details)			12 Months Ended
DEBT FINANCING - Narrative (Details)	Jul. 29, 2019 USD ($)	Jun. 05, 2018 USD ($)	Dec. 31, 2021 USD ($) property	Nov. 09, 2021 USD ($)	Jul. 09, 2021 USD ($) property	May 03, 2021 USD ($)	Dec. 31, 2020 USD ($)	Oct. 22, 2020 USD ($)	Aug. 30, 2019 USD ($)	Apr. 24, 2019 USD ($)	Dec. 21, 2018 USD ($)	Jun. 30, 2016 USD ($)
Debt Instrument [Line Items]
Carrying value			$ 2,948,944,000				$ 1,922,614,000
Credit Facility
Debt Instrument [Line Items]
Extension fee (percent)	0.075%
Unsecured debt \| Credit Facility
Debt Instrument [Line Items]
Maximum borrowing capacity	$ 1,550,000,000
Maximum borrowing capacity if expansion option is exercised	$ 1,750,000,000
Maximum total leverage ratio	60.00%
Maximum total leverage ratio allowable within two quarters of material acquisition	65.00%
Minimum fixed charge coverage ratio	1.5
Maximum unsecured debt to unencumbered asset value ratio	60.00%
Maximum unsecured debt to unencumbered asset value ratio allowable within two quarters of material acquisition	65.00%
Minimum encumbered adjusted net operating income to unsecured interest expense ratio	2.0
Unsecured debt \| Credit Facility \| Fed Funds Rate
Debt Instrument [Line Items]
Basis spread on variable rate (percent)	0.50%
Unsecured debt \| Credit Facility \| LIBOR
Debt Instrument [Line Items]
Basis spread on variable rate (percent)	1.00%
Unsecured debt \| Credit Facility \| LIBOR \| Minimum
Debt Instrument [Line Items]
Leverage based applicable margin (percent)	1.10%
Credit rating pricing election (percent)	0.78%
Unsecured debt \| Credit Facility \| LIBOR \| Maximum
Debt Instrument [Line Items]
Leverage based applicable margin (percent)	1.80%
Credit rating pricing election (percent)	1.65%
Unsecured debt \| Credit Facility \| Base Rate \| Minimum
Debt Instrument [Line Items]
Leverage based applicable margin (percent)	0.10%
Credit rating pricing election (percent)	0.00%
Unsecured debt \| Credit Facility \| Base Rate \| Maximum
Debt Instrument [Line Items]
Leverage based applicable margin (percent)	0.80%
Credit rating pricing election (percent)	0.65%
Unsecured debt \| 2023 Term loan facility
Debt Instrument [Line Items]
Maximum borrowing capacity if expansion option is exercised		$ 400,000,000
Effective interest rate (percent)			2.83%
Debt issued												$ 100,000,000
Maximum expansion option												$ 100,000,000
Aggregate amount of expansion option exercised		75,000,000
Carrying value		175,000,000	$ 175,000,000				175,000,000
Expansion option capacity increase		200,000,000
Current borrowing capacity		$ 225,000,000
Minimum number of rating agencies required \| property			2
Unsecured debt \| 2023 Term loan facility \| Fed Funds Rate
Debt Instrument [Line Items]
Basis spread on variable rate (percent)			0.50%
Unsecured debt \| 2023 Term loan facility \| LIBOR
Debt Instrument [Line Items]
Basis spread on variable rate (percent)			1.00%
Unsecured debt \| 2023 Term loan facility \| LIBOR \| Minimum
Debt Instrument [Line Items]
Leverage based applicable margin (percent)			1.30%
Credit rating pricing election (percent)			0.90%
Unsecured debt \| 2023 Term loan facility \| LIBOR \| Maximum
Debt Instrument [Line Items]
Leverage based applicable margin (percent)			1.70%
Credit rating pricing election (percent)			1.75%
Unsecured debt \| 2023 Term loan facility \| Base Rate \| Minimum
Debt Instrument [Line Items]
Leverage based applicable margin (percent)			0.30%
Credit rating pricing election (percent)			0.00%
Unsecured debt \| 2023 Term loan facility \| Base Rate \| Maximum
Debt Instrument [Line Items]
Leverage based applicable margin (percent)			0.70%
Credit rating pricing election (percent)			0.75%
Unsecured debt \| 2028 Term loan facility
Debt Instrument [Line Items]
Maximum borrowing capacity if expansion option is exercised											$ 125,000,000
Effective interest rate (percent)			4.62%
Debt issued											$ 75,000,000
Carrying value			$ 75,000,000				75,000,000
Minimum number of rating agencies required \| property			2
Unsecured debt \| 2028 Term loan facility \| Fed Funds Rate
Debt Instrument [Line Items]
Basis spread on variable rate (percent)			0.50%
Unsecured debt \| 2028 Term loan facility \| LIBOR
Debt Instrument [Line Items]
Basis spread on variable rate (percent)			1.00%
Unsecured debt \| 2028 Term loan facility \| LIBOR \| Minimum
Debt Instrument [Line Items]
Leverage based applicable margin (percent)			1.80%
Credit rating pricing election (percent)			1.40%
Unsecured debt \| 2028 Term loan facility \| LIBOR \| Maximum
Debt Instrument [Line Items]
Leverage based applicable margin (percent)			2.35%
Credit rating pricing election (percent)			2.25%
Unsecured debt \| 2028 Term loan facility \| Base Rate \| Minimum
Debt Instrument [Line Items]
Leverage based applicable margin (percent)			0.80%
Credit rating pricing election (percent)			0.40%
Unsecured debt \| 2028 Term loan facility \| Base Rate \| Maximum
Debt Instrument [Line Items]
Leverage based applicable margin (percent)			1.35%
Credit rating pricing election (percent)			1.25%
Unsecured debt \| 2029 Term loan facility
Debt Instrument [Line Items]
Effective interest rate (percent)			4.27%							4.27%
Debt issued										$ 100,000,000
Carrying value			$ 100,000,000				100,000,000
Minimum number of rating agencies required \| property			2
Unsecured debt \| 2029 Term loan facility \| Interest rate swap
Debt Instrument [Line Items]
Aggregate notional amount										$ 100,000,000
Unsecured debt \| 2029 Term loan facility \| Fed Funds Rate
Debt Instrument [Line Items]
Basis spread on variable rate (percent)			0.50%
Unsecured debt \| 2029 Term loan facility \| LIBOR
Debt Instrument [Line Items]
Basis spread on variable rate (percent)			1.00%
Unsecured debt \| 2029 Term loan facility \| LIBOR \| Minimum
Debt Instrument [Line Items]
Leverage based applicable margin (percent)			1.85%
Credit rating pricing election (percent)			1.40%
Unsecured debt \| 2029 Term loan facility \| LIBOR \| Maximum
Debt Instrument [Line Items]
Leverage based applicable margin (percent)			2.30%
Credit rating pricing election (percent)			2.25%
Unsecured debt \| 2029 Term loan facility \| Base Rate \| Minimum
Debt Instrument [Line Items]
Leverage based applicable margin (percent)			0.85%
Credit rating pricing election (percent)			0.40%
Unsecured debt \| 2029 Term loan facility \| Base Rate \| Maximum
Debt Instrument [Line Items]
Leverage based applicable margin (percent)			1.30%
Credit rating pricing election (percent)			1.25%
Unsecured debt \| 2029 Senior Unsecured Notes
Debt Instrument [Line Items]
Effective interest rate (percent)			3.98%
Debt issued									$ 100,000,000
Interest rate (percent)									3.98%
Carrying value			$ 100,000,000				100,000,000
Unsecured debt \| August 2031 Senior Unsecured Notes
Debt Instrument [Line Items]
Effective interest rate (percent)			4.08%
Debt issued									$ 50,000,000
Interest rate (percent)									4.08%
Carrying value			$ 50,000,000				50,000,000
Unsecured debt \| August 2030 Senior Unsecured Notes
Debt Instrument [Line Items]
Effective interest rate (percent)			2.99%
Debt issued								$ 150,000,000
Interest rate (percent)								2.99%
Carrying value			$ 150,000,000				150,000,000
Unsecured debt \| 2032 Senior Unsecured Notes
Debt Instrument [Line Items]
Effective interest rate (percent)			3.09%
Debt issued								$ 100,000,000
Interest rate (percent)								3.09%
Carrying value			$ 100,000,000				100,000,000
Unsecured debt \| 2026 Senior Unsecured Notes
Debt Instrument [Line Items]
Effective interest rate (percent)			2.16%
Debt issued						$ 35,000,000
Interest rate (percent)						2.16%
Carrying value			$ 35,000,000				0
Unsecured debt \| May 2031 Senior Unsecured Notes
Debt Instrument [Line Items]
Effective interest rate (percent)			3.00%
Debt issued						$ 90,000,000
Interest rate (percent)						3.00%
Carrying value			$ 90,000,000				0
Unsecured debt \| May 2033 Senior Unsecured Notes
Debt Instrument [Line Items]
Effective interest rate (percent)			3.10%
Debt issued						$ 55,000,000
Interest rate (percent)						3.10%
Carrying value			$ 55,000,000				0
Unsecured debt \| November 2030 Senior Unsecured Notes
Debt Instrument [Line Items]
Effective interest rate (percent)			2.72%
Debt issued				$ 75,000,000
Interest rate (percent)				2.72%
Carrying value			$ 75,000,000				0
Unsecured debt \| November 2031 Senior Unsecured Notes
Debt Instrument [Line Items]
Effective interest rate (percent)			2.81%
Debt issued				$ 175,000,000
Interest rate (percent)				2.81%
Carrying value			$ 175,000,000				0
Unsecured debt \| November 2033 Senior Notes
Debt Instrument [Line Items]
Debt issued				$ 125,000,000
Interest rate (percent)				2.96%
Unsecured debt \| 2036 Senior Unsecured Notes
Debt Instrument [Line Items]
Effective interest rate (percent)			3.06%
Debt issued				$ 75,000,000
Interest rate (percent)				3.06%
Carrying value			$ 75,000,000				0
Fixed rate mortgages payable \| Fixed rate mortgages payable
Debt Instrument [Line Items]
Effective interest rate (percent)			3.82%
Carrying value			$ 303,944,000				223,614,000
Fixed rate mortgages payable \| Fixed rate mortgages payable \| Minimum
Debt Instrument [Line Items]
Effective interest rate (percent)			3.63%
Fixed rate mortgages payable \| Fixed rate mortgages payable \| Maximum
Debt Instrument [Line Items]
Effective interest rate (percent)			5.00%
Fixed rate mortgages payable \| 2028 Fixed Rate Mortgage Payable
Debt Instrument [Line Items]
Debt issued					$ 88,000,000
Interest rate (percent)					2.77%
Number of properties securing debt \| property					8
Revolving line of credit \| Credit Facility \| Minimum
Debt Instrument [Line Items]
Usage based fees with respect to unused portion of Revolver (percent)	0.15%
Ratings based fees if credit pricing elected (percent)	0.125%
Revolving line of credit \| Credit Facility \| Maximum
Debt Instrument [Line Items]
Usage based fees with respect to unused portion of Revolver (percent)	0.20%
Ratings based fees if credit pricing elected (percent)	0.30%
Revolving line of credit \| Revolving line of credit \| Credit Facility
Debt Instrument [Line Items]
Maximum borrowing capacity	$ 650,000,000
Effective interest rate (percent)			1.35%
Revolving line of credit remaining borrowing capacity			$ 154,300,000
Carrying value			$ 490,000,000				174,000,000
Term loan A \| Unsecured debt \| Credit Facility
Debt Instrument [Line Items]
Maximum borrowing capacity	125,000,000
Effective interest rate (percent)			3.69%
Carrying value			$ 125,000,000				125,000,000
Term loan B \| Unsecured debt \| Credit Facility
Debt Instrument [Line Items]
Maximum borrowing capacity	250,000,000
Effective interest rate (percent)			2.86%
Carrying value			$ 250,000,000				250,000,000
Term loan C \| Unsecured debt \| Credit Facility
Debt Instrument [Line Items]
Maximum borrowing capacity	225,000,000
Effective interest rate (percent)			2.86%
Carrying value			$ 225,000,000				225,000,000
Term loan D \| Unsecured debt \| Credit Facility
Debt Instrument [Line Items]
Maximum borrowing capacity	175,000,000
Effective interest rate (percent)			3.07%
Carrying value			$ 175,000,000				175,000,000
Term loan E \| Unsecured debt \| Credit Facility
Debt Instrument [Line Items]
Maximum borrowing capacity	$ 125,000,000
Effective interest rate (percent)			1.25%
Carrying value			$ 125,000,000				$ 0
Letter of credit \| Revolving line of credit \| Credit Facility
Debt Instrument [Line Items]
Letters of credit outstanding			$ 5,700,000