Summary Of The Unconsolidated Joint Ventures' Financial Statements (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011	Dec. 31, 2011
Schedule of Equity Method Investments [Line Items]
Investment in storage facilities, net	$ 1,342,972		$ 1,342,972		$ 1,245,873
Other assets	5,510		5,510		7,373
Total Assets	1,397,348		1,397,348		1,343,674
Mortgages payable	4,295		4,295		4,423
Total Liabilities	657,966		657,966		673,669
Depreciation and amortization	(10,427)	(8,585)	(30,461)	(25,164)
Sovran HHF Storage Holdings LLC [Member]
Schedule of Equity Method Investments [Line Items]
Investment in storage facilities, net	160,556		160,556
Other assets	5,007		5,007
Total Assets	165,563		165,563
Due to the Company	321		321
Mortgages payable	64,790		64,790
Other liabilities	3,228		3,228
Total Liabilities	68,339		68,339
Unaffiliated partners' equity (deficiency)	77,779		77,779
Company equity (deficiency)	19,445		19,445
Total Partners' Equity (deficiency)	97,224		97,224
Total Liabilities and Partners' Equity (deficiency)	165,563		165,563
Total revenues			14,709
Depreciation and amortization			(2,770)
Other expenses			(9,520)
Net income			2,419
Sovran HHF Storage Holdings II LLC [Member]
Schedule of Equity Method Investments [Line Items]
Investment in storage facilities, net	190,986		190,986
Other assets	4,517		4,517
Total Assets	195,503		195,503
Due to the Company	336		336
Mortgages payable	104,444		104,444
Other liabilities	2,174		2,174
Total Liabilities	106,954		106,954
Unaffiliated partners' equity (deficiency)	75,206		75,206
Company equity (deficiency)	13,343		13,343
Total Partners' Equity (deficiency)	88,549		88,549
Total Liabilities and Partners' Equity (deficiency)	195,503		195,503
Total revenues			17,351
Depreciation and amortization			(3,972)
Other expenses			(12,780)
Net income			599
Iskalo Office Holdings, LLC [Member]
Schedule of Equity Method Investments [Line Items]
Investment in office building	5,182		5,182
Other assets	611		611
Total Assets	5,793		5,793
Mortgages payable	6,636		6,636
Other liabilities	720		720
Total Liabilities	7,356		7,356
Unaffiliated partners' equity (deficiency)	(1,070)		(1,070)
Company equity (deficiency)	(493)		(493)
Total Partners' Equity (deficiency)	(1,563)		(1,563)
Total Liabilities and Partners' Equity (deficiency)	5,793		5,793
Total revenues			836
Depreciation and amortization			(175)
Other expenses			(642)
Net income			$ 19