Consolidated Statements Of Cash Flows (USD $)	9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011
Operating Activities
Net income	$ 42,087,000	$ 21,147,000
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	31,247,000	26,222,000
Amortization of deferred financing fees	627,000	931,000
Gain on sale of storage facilities	(4,498,000)
Equity in (income) losses of joint ventures	(608,000)	408,000
Distributions from unconsolidated joint venture	1,471,000	471,000
Non-vested stock earned	1,906,000	1,026,000
Stock option expense	238,000	253,000
Changes in assets and liabilities (excluding the effects of acquisitions):
Accounts receivable	(308,000)	68,000
Prepaid expenses	(1,025,000)	(527,000)
Accounts payable and other liabilities	(2,242,000)	5,895,000
Deferred revenue	(413,000)	44,000
Net cash provided by operating activities	68,482,000	55,938,000
Investing Activities
Acquisitions of storage facilities	(105,137,000)	(145,873,000)
Improvements, equipment additions, and construction in progress	(20,813,000)	(17,181,000)
Net proceeds from the sale of storage facilities	47,698,000
Investment in unconsolidated joint ventures	(3,482,000)	(12,150,000)
Advances to joint ventures	(62,000)	(326,000)
Reimbursement of (payment of) property deposits	365,000	(347,000)
Net cash used in investing activities	(81,431,000)	(175,877,000)
Financing Activities
Net proceeds from sale of common stock	78,314,000	5,679,000
Proceeds from line of credit	70,000,000	413,000,000
Repayments of line of credit	(90,000,000)	(234,000,000)
Financing costs		(4,060,000)
Dividends paid-common stock	(39,317,000)	(37,366,000)
Distributions to noncontrolling interest holders	(458,000)	(1,025,000)
Redemption of operating partnership units	(7,364,000)
Additional investment in Locke Sovran II LLC		(14,199,000)
Mortgage principal payments	(128,000)	(7,283,000)
Net cash provided by financing activities	11,047,000	120,746,000
Net (decrease) increase in cash	(1,902,000)	807,000
Cash at beginning of period	7,321,000	5,766,000
Cash at end of period	5,419,000	6,573,000
Supplemental cash flow information
Cash paid for interest, net of interest capitalized	$ 24,808,000	$ 26,582,000