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

Quarterly report pursuant to Section 13 or 15(d)

SUBSEQUENT EVENTS (Details)

SUBSEQUENT EVENTS (Details) (USD $)	0 Months Ended	1 Months Ended	3 Months Ended		0 Months Ended	2 Months Ended	1 Months Ended	0 Months Ended
SUBSEQUENT EVENTS (Details) (USD $)	Jan. 01, 2015 property	Jan. 31, 2015 property	Mar. 31, 2015 property	Mar. 31, 2014	Jun. 03, 2015	May 31, 2015 property	Jun. 05, 2015	Apr. 28, 2015	Apr. 11, 2015	Apr. 01, 2015	May 18, 2015	Dec. 31, 2014
Subsequent Event [Line Items]
Number of self storage properties acquired	5us-gaap_NumberOfBusinessesAcquired	6us-gaap_NumberOfBusinessesAcquired	6us-gaap_NumberOfBusinessesAcquired
Aggregate purchase price			$ 34,235,000
Consideration given, cash			6,991,000	1,850,000
Consideration given, value of OP Equity			8,954,000
Liabilities assumed, mortgages			16,442,000
Revolving line of credit [Member] \| Credit Facility [Member] \| London Interbank Offered Rate (LIBOR) [Member] \| Line of Credit [Member]
Subsequent Event [Line Items]
Reduced borrowing rate			2.50%
Term Loan [Member] \| Credit Facility [Member] \| London Interbank Offered Rate (LIBOR) [Member] \| Line of Credit [Member]
Subsequent Event [Line Items]
Reduced borrowing rate			2.40%
National Storage Affiliates Holdings LLC [Member] \| OP units [Member] \| NSA OP, LP [Member]
Subsequent Event [Line Items]
Shares redeemed from NSA Holdings (in shares)			126,400									126,400
National Storage Affiliates Holdings LLC [Member] \| Common Shares [Member] \| National Storage Affiliates Trust [Member]
Subsequent Event [Line Items]
Shares redeemed from NSA Holdings (in shares)			1,000
Subsequent Event [Member]
Subsequent Event [Line Items]
Number of self storage properties acquired						21
Cash dividend (in dollars per share)					$ 0.15
Cash dividend (in dollars per unit)					$ 0.15
Subsequent Event [Member] \| Credit Facility [Member] \| Line of Credit [Member]
Subsequent Event [Line Items]
Debt covenant, required real estate property owned, maximum borrowing base, percent							60.00%
Debt covenant, maximum total leverage							60.00%
Debt covenant, minimum interest coverage ratio							1.5
Debt covenant, required minimum net worth							133,300,000
Debt covenant, required proceeds of equity issuances, percent							75.00%
Subsequent Event [Member] \| Revolving line of credit [Member] \| Credit Facility [Member] \| London Interbank Offered Rate (LIBOR) [Member] \| Line of Credit [Member]
Subsequent Event [Line Items]
Reduction in pricing grids, basis points reduced							1.00%
Reduced borrowing rate							1.60%
Subsequent Event [Member] \| Term Loan [Member] \| Credit Facility [Member] \| London Interbank Offered Rate (LIBOR) [Member] \| Line of Credit [Member]
Subsequent Event [Line Items]
Reduction in pricing grids, basis points reduced							1.00%
Reduced borrowing rate							1.50%
Subsequent Event [Member] \| April - May 2015 Acquisitions [Member]
Subsequent Event [Line Items]
Number of self storage properties acquired						21
Aggregate purchase price						93,100,000
Consideration given, cash						41,300,000
Cash received in acquisition						600,000
Consideration given, value of OP Equity						23,000,000
Liabilities assumed, mortgages						28,600,000
Subsequent Event [Member] \| April - May 2015 Acquisitions [Member] \| Subordinated performance units [Member]
Subsequent Event [Line Items]
Equity interest issued (in units)						345,970
Subsequent Event [Member] \| April - May 2015 Acquisitions [Member] \| OP units [Member]
Subsequent Event [Line Items]
Equity interest issued (in units)						1,420,098
Subsequent Event [Member] \| 2013 Equity Incentive Plan [Member]
Subsequent Event [Line Items]
Shares vested							43,350
Share based compensation expense							400,000
Subsequent Event [Member] \| National Storage Affiliates Holdings LLC [Member] \| Common Shares [Member] \| National Storage Affiliates Trust [Member]
Subsequent Event [Line Items]
Shares redeemed from NSA Holdings (in shares)								1,000
Subsequent Event [Member] \| Parent Company [Member] \| NSA OP, LP [Member] \| OP units [Member]
Subsequent Event [Line Items]
Exchanged net proceeds from initial public offering for equity (in shares)								23,000,000
Subsequent Event [Member] \| Participating Regional Operator [Member] \| April - May 2015 Acquisitions [Member] \| Affiliated Entity [Member]
Subsequent Event [Line Items]
Number of self storage properties acquired						4
Subsequent Event [Member] \| Unidentified Third Parties [Member] \| April - May 2015 Acquisitions [Member]
Subsequent Event [Line Items]
Number of self storage properties acquired						17
Subsequent Event [Member] \| Dividend declared for three months ended March 31, 2015 [Member] \| Class A And B Units [Member]
Subsequent Event [Line Items]
Declared distributions									7,400,000
Subsequent Event [Member] \| Dividend declared for April 1 through April 20, 2015 [Member] \| Class A And B Units [Member]
Subsequent Event [Line Items]
Declared distributions									1,600,000
Subsequent Event [Member] \| Call Center [Member] \| SecuCare Self Storage Inc. [Member] \| Call Center Services [Member] \| Affiliated Entity [Member]
Subsequent Event [Line Items]
Issuance of OP units and subordinated performance units for acquisition of call center										50,000
Common Shares [Member] \| Subsequent Event [Member] \| IPO [Member]
Subsequent Event [Line Items]
Shares offered including underwriters option								20,000,000
Share price								13.00
Total net proceeds from initial public offering								236,400,000
Common Shares [Member] \| Subsequent Event [Member] \| Over-Allotment Option [Member]
Subsequent Event [Line Items]
Shares offered including underwriters option											3,000,000
Total net proceeds from initial public offering											$ 36,300,000