Property Acquisitions and Dispositions - Reconciliation of Purchase Price to Cash Paid by the Company (Details) - USD ($) $ in Thousands		12 Months Ended
	Oct. 01, 2015	Dec. 31, 2016	Dec. 31, 2015
Property Acquisition And Dispositions [Line Items]
Total purchase price attributable to the Company		$ 74,235	$ 142,399
Cash Paid		$ 995,759	$ 1,517,196
SmartStop Self Storage, Inc (SmartStop) [Member]
Property Acquisition And Dispositions [Line Items]
Total purchase price	$ 1,391,272
Less: amount paid for Excluded Assets by Strategic 1031	(90,360)
Total purchase price attributable to the Company	1,300,912
Cash Paid	1,272,256
Fair value of OP Units issued to certain SmartStop unit holders	28,656
Less: Cash paid for transaction costs	8,053
Less: Cash paid for defeasance and prepayment fees	38,360
Less: Severance and share-based compensation to SmartStop employees	7,665
Total consideration transferred	$ 1,246,834