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

DEBT FINANCING - Debt Summary (Details) - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016	Jun. 30, 2016
Debt Instrument [Line Items]
Total principal	$ 964,932	$ 873,194
Unamortized debt issuance costs and debt premium, net	4,208	5,760
Total debt	$ 969,140	878,954
Line of Credit [Member] \| Credit Facility [Member] \| Revolving line of credit [Member]
Debt Instrument [Line Items]
Effective interest rate (percent)	2.62%		1.87%
Total principal	$ 181,000	246,500
Unsecured Debt [Member] \| Credit Facility [Member] \| Tranche A Term Loan [Member]
Debt Instrument [Line Items]
Effective interest rate (percent)	2.60%
Total principal	$ 235,000	225,000
Unsecured Debt [Member] \| Credit Facility [Member] \| Tranche B Term Loan [Member]
Debt Instrument [Line Items]
Effective interest rate (percent)	3.24%
Total principal	$ 155,000	100,000
Unsecured Debt [Member] \| Credit Facility [Member] \| Tranche C Term Loan [Member]
Debt Instrument [Line Items]
Effective interest rate (percent)	3.71%
Total principal	$ 105,000	0
Unsecured Debt [Member] \| Term Loan Facility [Member]
Debt Instrument [Line Items]
Effective interest rate (percent)	3.08%
Total principal	$ 100,000	100,000
Mortgages [Member] \| Fixed Rate Mortgages [Member]
Debt Instrument [Line Items]
Effective interest rate (percent)	4.15%
Total principal	$ 188,932	$ 201,694