National Storage Affiliates Trust - 10-K filing on 2016-03-10

RELATED PARTY TRANSACTIONS (Details) $ in Thousands			1 Months Ended	3 Months Ended									6 Months Ended	9 Months Ended	12 Months Ended
RELATED PARTY TRANSACTIONS (Details) $ in Thousands	Apr. 01, 2015 shares	Feb. 28, 2014 USD ($) property	Jan. 31, 2015 property	Dec. 31, 2015 USD ($) ft² property	Sep. 30, 2015 USD ($) property	Jun. 30, 2015 USD ($) property	Mar. 31, 2015 USD ($) property	Dec. 31, 2014 USD ($) property	Sep. 30, 2014 USD ($) property	Jun. 30, 2014 USD ($) property	Mar. 31, 2014 USD ($) property	Mar. 31, 2013 USD ($)	Dec. 31, 2014 USD ($) property	Dec. 31, 2013 USD ($)	Dec. 31, 2015 USD ($) ft² property shares	Dec. 31, 2014 USD ($) property	Dec. 31, 2012 property	Jul. 01, 2014 USD ($)
Related Party Transaction [Line Items]
Affiliate payroll costs included in property operating expenses														$ 11,886	$ 45,412	$ 27,913
Note receivable from PRO				$ 0				$ 1,778					$ 1,778		$ 0	$ 1,778
Number of self storage properties acquired \| property				16	15	21	6	15	31	36	1				58	83	43
Loan receivable settled in self storage property acquisition				$ 0	$ 0	$ 0	$ 1,778	$ 0	$ 0	$ 0	$ 0				$ 1,778	$ 0
Receivable balance netted against equity interest issued in business acquisition								400	$ 4,800
Participating Regional Operator [Member] \| Management [Member]
Related Party Transaction [Line Items]
Businesses acquired with bridge loans \| property													13
Number of self storage properties acquired \| property		2	2										16
Loan receivable settled in self storage property acquisition													$ 6,200
Receivable balance netted against equity interest issued in business acquisition													5,200		1,400
Reimbursements received on assumed mortgages															$ 1,600
Units issued upon reimbursement of assumed mortgages \| shares															85,130
Bridge loan agreement				$ 5,300											$ 5,300
Related party loan, weighted average fixed rate				3.30%											3.30%
Participating Regional Operator [Member] \| Management [Member] \| Other assets, net [Member]
Related Party Transaction [Line Items]
Note receivable from PRO								$ 1,800					$ 1,800			$ 1,800
Participating Regional Operator [Member] \| Affiliated Entity [Member]
Related Party Transaction [Line Items]
Number of self storage properties acquired \| property															25	60
SecuCare Self Storage Inc. [Member] \| Affiliated Entity [Member]
Related Party Transaction [Line Items]
Fees and expenses																$ 2,700
Supervisory and Administrative Fee Agreement [Member] \| Participating Regional Operator [Member] \| Management [Member]
Related Party Transaction [Line Items]
Supervisory and administrative fees included in general and administrative expenses														2,000	$ 7,600	4,500
Supervisory and Administrative Fee Agreement [Member] \| Participating Regional Operator [Member] \| Minimum [Member] \| Management [Member]
Related Party Transaction [Line Items]
Supervisory and administrative fee, percent of gross revenues															5.00%
Supervisory and Administrative Fee Agreement [Member] \| Participating Regional Operator [Member] \| Maximum [Member] \| Management [Member]
Related Party Transaction [Line Items]
Supervisory and administrative fee, percent of gross revenues															6.00%
Affiliate Payroll Services [Member] \| Participating Regional Operator [Member] \| Management [Member]
Related Party Transaction [Line Items]
Affiliate payroll costs included in property operating expenses														3,600	$ 13,400	8,400
Affiliate Call Center Services [Member] \| SecuCare Self Storage Inc. [Member] \| Affiliated Entity [Member]
Related Party Transaction [Line Items]
Area occupied by call center \| ft²				1,500											1,500
Annual rent for call center															$ 25
Fees and expenses														300	200	500
Affiliate Call Center Services [Member] \| SecuCare Self Storage Inc. [Member] \| Affiliated Entity [Member] \| Call Center [Member]
Related Party Transaction [Line Items]
Issuance of OP units and subordinated performance units for acquisition of call center \| shares	50,000
Brokerage Fees [Member] \| Participating Regional Operator [Member] \| Management [Member]
Related Party Transaction [Line Items]
Fees and expenses														$ 500	200	300
Related Party Note [Member] \| Participating Regional Operator [Member] \| Management [Member]
Related Party Transaction [Line Items]
Note receivable from PRO		$ 4,800																$ 8,000
Related party note interest rate		5.16%
NSA Predecessor [Member]
Related Party Transaction [Line Items]
Affiliate payroll costs included in property operating expenses												$ 2,926
NSA Predecessor [Member] \| Supervisory and Administrative Fee Agreement [Member] \| Participating Regional Operator [Member] \| Management [Member]
Related Party Transaction [Line Items]
Supervisory and administrative fee, percent of gross revenues												6.00%
Supervisory and administrative fees included in general and administrative expenses												$ 400
NSA Predecessor [Member] \| Affiliate Payroll Services [Member] \| Participating Regional Operator [Member] \| Management [Member]
Related Party Transaction [Line Items]
Affiliate payroll costs included in property operating expenses												900
NSA Predecessor [Member] \| Affiliate Call Center Services [Member] \| SecuCare Self Storage Inc. [Member] \| Affiliated Entity [Member]
Related Party Transaction [Line Items]
Fees and expenses												$ 100
Acquisition Costs [Member] \| Due Diligence Costs [Member] \| Participating Regional Operator [Member] \| Management [Member]
Related Party Transaction [Line Items]
Fees and expenses															$ 600	$ 200