CONSOLIDATED STATEMENTS OF INCOME (unaudited) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended
	Mar. 31, 2012	Mar. 31, 2011
REVENUE
Rental	$ 114,468	$ 97,145
Other	255	139
Total revenue	114,723	97,284
EXPENSES
Depreciation and amortization	35,250	26,608
Interest	28,952	25,122
General and administrative	9,168	7,870
Property	2,536	1,705
Income taxes	405	368
Total expenses	76,311	61,673
Income from continuing operations	38,412	35,611
Income from discontinued operations	851	388
Net income	39,263	35,999
Preferred stock dividends	(9,496)	(6,063)
Excess of redemption value over carrying value of preferred shares redeemed (see note 8)	(3,696)	0
Net income available to common stockholders	$ 26,071	$ 29,936
Income from continuing operations:
Basic (in dollars per share)	$ 0.19	$ 0.25
Diluted (in dollars per share)	$ 0.19	$ 0.25
Net income:
Basic (in dollars per share)	$ 0.20	$ 0.25
Diluted (in dollars per share)	$ 0.20	$ 0.25
Weighted average common shares outstanding:
Basic (in shares)	132,577,100	118,960,878
Diluted (in shares)	132,703,954	119,109,044