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

EQUITY-BASED AWARDS - Acquisition Related LTIP Units (Details) - shares	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Number of LTIP units
Forfeited (in shares)	(118,300)
2013 Long-Term Incentive Plan [Member] \| LTIP units [Member]
Number of LTIP units
Outstanding unvested at beginning of year (in shares)	236,265	509,166	287,600
Vested (in shares)	(119,282)	(278,901)	(156,984)
Unvested at end of year (in shares)	294,529	236,265	509,166
Participating Regional Operator [Member] \| 2013 Long-Term Incentive Plan [Member] \| LTIP units [Member]
Number of LTIP units
Outstanding unvested at beginning of year (in shares)	423,800	522,900	1,262,070
Vested (in shares)	(45,100)	(99,100)	(379,970)
Unvested at end of year (in shares)	260,400	423,800	522,900
NSA Predecessor [Member] \| 2013 Long-Term Incentive Plan [Member] \| LTIP units [Member]
Number of LTIP units
Vested (in shares)			(359,200)