National Storage Affiliates Trust Quarterly report pursuant to Section 13 or 15(d)

Quarterly report pursuant to Section 13 or 15(d)

SHAREHOLDERS' EQUITY AND NONCONTROLLING INTERESTS - Narrative (Details)

SHAREHOLDERS' EQUITY AND NONCONTROLLING INTERESTS - Narrative (Details) $ / shares in Units, $ in Millions				3 Months Ended						9 Months Ended
	Mar. 16, 2023 USD ($) property shares	Mar. 15, 2023 shares	Feb. 27, 2019 USD ($) $ / shares	Sep. 30, 2023 USD ($) property $ / shares shares	Jun. 30, 2023 shares	Mar. 31, 2023 shares	Sep. 30, 2022 shares	Jun. 30, 2022 shares	Mar. 31, 2022 shares	Sep. 30, 2023 USD ($) property $ / shares shares	Dec. 31, 2022 $ / shares	Jul. 11, 2022 USD ($)	May 19, 2021 USD ($)
Class of Stock [Line Items]
Common shares of beneficial interest, par value (in dollars per share) \| $ / shares			$ 0.01	$ 0.01						$ 0.01	$ 0.01
Authorized amount \| $												$ 400.0
Repurchase of common shares (in shares)										7,983,868
Stock repurchased \| $										$ (282.7)
Remaining repurchase capacity \| $												$ 27.6
Number of self storage properties \| property				1,119						1,119
Common Shares
Class of Stock [Line Items]
Repurchase of common shares (in shares)				6,360,994		1,622,874	953,924
Redemptions/conversions of units (in shares)				667,484	354,936	67,431	61,662	294,573	258,477
NSA OP, LP \| Series A Cumulative Redeemable Preferred Shares of Beneficial Interest, par value $0.01 per share
Class of Stock [Line Items]
Preferred units cash redemption price (in dollars per share) \| $ / shares				$ 25.00						$ 25.00
Series B Cumulative Redeemable Preferred Shares of Beneficial Interest, par value $0.01 per share
Class of Stock [Line Items]
Shares tied to promissory note (in shares)	1,059,683
Series B Cumulative Redeemable Preferred Shares of Beneficial Interest, par value $0.01 per share \| Personal Mini
Class of Stock [Line Items]
Issuance of shares, net of offering costs (in shares)	5,668,128
Series B preferred shares \| $	$ 139.6
Number of self storage properties \| property	15
Financing Receivable, after Allowance for Credit Loss \| $	$ 26.1
Series A and B Preferred shares of beneficial interest, shares authorized, issued and outstanding at liquidation preference \| $	26.1
Proceeds from issuance of preferred stock \| $	113.2
Series B Cumulative Redeemable Preferred Shares of Beneficial Interest, par value $0.01 per share \| NSA OP, LP
Class of Stock [Line Items]
Preferred share/unit dividend rate (percent)		6.00%
Preferred shares of beneficial interest, authorized (in shares)		7,000,000
Preferred units stated value (in dollars per share) \| $ / shares				$ 25.00						$ 25.00
Series A Preferred Shares \| NSA OP, LP
Class of Stock [Line Items]
Preferred share/unit dividend rate (percent)		6.00%
Series A-1 preferred units \| NSA OP, LP
Class of Stock [Line Items]
Preferred share/unit dividend rate (percent)										6.00%
Unit conversion ratio										1
Merger and internalization of PRO, net of issuance costs (in shares)										287,337
Stock issued in connection with termination of lease (in shares)										33,441
Subordinated performance units
Class of Stock [Line Items]
Time frame prior to conversion for conversion metric (in years)										1 year
Percentage of cash available for distribution used in conversion ratio calculation										110.00%
Subordinated performance units \| NSA OP, LP
Class of Stock [Line Items]
Unit conversion ratio										1
Issuance of shares/units, non-voluntary (in shares)										926,623
Redemptions/conversions of units (in shares)										926,623
Unit conversion, lock out period (in years)										2 years
Subordinated performance units \| NSA OP, LP \| Northwest Retirement
Class of Stock [Line Items]
Redemptions/conversions of units (in shares)										397,000
Subordinated performance units \| NSA OP, LP \| Retirement of Northwest
Class of Stock [Line Items]
Issuance of shares, net of offering costs (in shares)										1,124,924
Subordinated performance units \| Personal Mini Affiliate \| Personal Mini
Class of Stock [Line Items]
Payments to acquire interest in subsidiaries and affiliates \| $	$ 26.1
OP units \| Self Storage Property Acquisition
Class of Stock [Line Items]
Merger and internalization of PRO, net of issuance costs (in shares)										18,895
OP units \| NSA OP, LP
Class of Stock [Line Items]
Issuance of shares, net of offering costs (in shares)										2,545,063
Unit conversion ratio				1						1
OP units \| NSA OP, LP \| Common Shares
Class of Stock [Line Items]
Redemptions/conversions of units (in shares)										1,089,851
OP units \| NSA OP, LP \| Northwest Retirement
Class of Stock [Line Items]
Issuance of shares, net of offering costs (in shares)										481,811
OP units \| NSA OP, LP \| Retirement of Northwest
Class of Stock [Line Items]
Issuance of shares, net of offering costs (in shares)										2,545,063
OP units \| DownREIT Partnership
Class of Stock [Line Items]
Issuance of shares, net of offering costs (in shares)										195,573
Unit conversion ratio				1
LTIP units \| NSA OP, LP
Class of Stock [Line Items]
Issuance of shares, net of offering costs (in shares)										185,529
Unit conversion ratio				1						1
Conversion of units (in shares)										128,487
DownREIT Subordinated Performance Performance Units \| NSA OP, LP
Class of Stock [Line Items]
Conversion of stock (in shares)										203,637
At The Market Program
Class of Stock [Line Items]
Value of common and preferred shares authorized under ATM program \| $													$ 400.0
Value of remaining available offered shares \| $				$ 169.1						$ 169.1			$ 31.0
Prior Sales Agreement
Class of Stock [Line Items]
Value of common and preferred shares authorized under ATM program \| $			$ 250.0
Preferred share/unit dividend rate (percent)			6.00%