Consolidated Balance Sheets (USD $) In Thousands, unless otherwise specified	Mar. 31, 2014	Dec. 31, 2013
Investment in storage facilities:
Land	$ 346,052	$ 312,053
Building, equipment, and construction in progress	1,617,007	1,552,584
Real estate investment property, at cost, total	1,963,059	1,864,637
Less: accumulated depreciation	(377,685)	(366,472)
Investment in storage facilities, net	1,585,374	1,498,165
Cash and cash equivalents	6,260	9,524
Accounts receivable	4,774	5,119
Receivable from unconsolidated joint ventures	860	883
Investment in unconsolidated joint ventures	30,199	30,391
Prepaid expenses	7,594	5,978
Fair value of interest rate swap agreements	580	794
Other assets	7,367	11,021
Total Assets	1,643,008	1,561,875
Liabilities
Line of credit	115,000	49,000
Term notes	575,000	575,000
Accounts payable and accrued liabilities	27,095	37,741
Deferred revenue	7,589	6,708
Fair value of interest rate swap agreements	9,233	7,523
Mortgages payable	2,223	2,254
Total Liabilities	736,140	678,226
Noncontrolling redeemable Operating Partnership Units at redemption value	14,535	12,940
Shareholders' Equity
Common stock $.01 par value, 100,000,000 shares authorized, 32,938,654 shares issued and outstanding at March 31, 2014 (32,532,991 at December 31, 2013)	341	337
Additional paid-in capital	1,097,014	1,066,399
Dividends in excess of net income	(169,516)	(162,450)
Accumulated other comprehensive loss	(8,331)	(6,402)
Treasury stock at cost, 1,171,886 shares	(27,175)	(27,175)
Total Shareholders' Equity	892,333	870,709
Total Liabilities and Shareholders' Equity	$ 1,643,008	$ 1,561,875