Summary of Significant Accounting Policies - Additional Information (Detail) (USD $)	1 Months Ended		12 Months Ended
	May 31, 2012	Jan. 31, 2010	Dec. 31, 2013 Term sqft	Dec. 31, 2012	Dec. 31, 2011
Summary Of Significant Accounting Policies [Line Items]
Additional interest acquired in VIE as primary beneficiary		2.00%
Net interest in property		12.00%
Initial term of lease			10 years
Number of successive five year terms			4
Extension period of operating lease			5 years
Net real estate asset in consolidated joint venture			$ 16,600,000
Portion of consolidated secured debt			10,100,000
Portion of non-controlling interest			5,700,000
Purchase price allocation to intangible assets			7,050,000	7,260,000
Amount paid as acquisition fees			2,900,000	3,600,000	7,700,000
Impairment losses of long-lived assets			0	0
Aggregate investment			100,000
Percentage of ownership interest			1.49%
Redemption of equity interest	1,400,000
Gain on sale of investment in unconsolidated joint venture	800,000			815,000
Area of lease to single tenant			356,000
Maximum exposure to loss			27,600,000
Maturity date of guaranteed loan			Aug. 01, 2020
Estimated amortization expenses of intangible assets in 2014			5,400,000
Estimated amortization expenses of intangible assets in 2015			3,400,000
Estimated amortization expenses of intangible assets in 2016			1,600,000
Estimated amortization expenses of intangible assets in 2017			0
Estimated amortization expenses of intangible assets in 2018			0
Accumulated amortization of deferred financing costs			5,900,000	4,400,000
Maximum period for reimbursement of offering cost			60 days
Maximum offering cost rate			3.50%
Net gain (loss) recorded on foreign currency transactions			(460,000)	60,000	(17,000)
Minimum percentage of ordinary taxable income to be distributed to stockholders			90.00%
Antidilutive unvested restricted stock not included in diluted weighted average shares			6,250	6,250	6,875
Fair Value, Inputs, Level 2
Summary Of Significant Accounting Policies [Line Items]
Derivative liabilities classified in accounts payable and accrued liabilities, at fair value			303,051
Westport Lax LLC
Summary Of Significant Accounting Policies [Line Items]
Area of lease to single tenant			356,000
Ownership interest in equity method investment			12.00%
Carrying value of equity method investment			1,300,000
Ownership percentage of affiliates			78.00%
Preferred equity distribution percentage			10.00%
Amount of investment			6,900,000
Non-interest bearing receivable			400,000
Remaining interest owned by third party			10.00%
Hawthorne Property
Summary Of Significant Accounting Policies [Line Items]
Maximum exposure to loss			19,000,000
Variable Interest Entities Acquired in 2009 Mergers [Member]
Summary Of Significant Accounting Policies [Line Items]
Number of interests in unconsolidated joint ventures deemed to be VIEs			5
Delaware statutory trust (DST)
Summary Of Significant Accounting Policies [Line Items]
Passive or limited partner interests in storage facilities			2
Scenario, Actual [Member]
Summary Of Significant Accounting Policies [Line Items]
Maximum offering cost rate			3.50%
Personal Property | Minimum
Summary Of Significant Accounting Policies [Line Items]
Estimated useful life			3 years
Personal Property | Maximum
Summary Of Significant Accounting Policies [Line Items]
Estimated useful life			5 years
In-place lease intangibles
Summary Of Significant Accounting Policies [Line Items]
Accumulated amortization of lease intangibles			$ 44,600,000	$ 36,400,000