Condensed Consolidated Statements of Operations and Comprehensive Income (Unaudited) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
Revenues:
Rental and other property	$ 146,394	$ 125,474
Management and other fees	2,948	2,444
Total revenues	149,342	127,918
Expenses:
Property operating, excluding real estate taxes	32,608	28,751
Real estate taxes	14,156	11,413
Depreciation	47,144	40,734
General and administrative	6,626	5,400
Cost of management and other fees	1,701	1,640
Total expenses	102,235	87,938
Earnings from operations	47,107	39,980
Interest expense before amortization	(25,211)	(24,658)
Amortization expense	(2,930)	(2,871)
Interest and other income	5,023	2,413
Equity income in co-investments	4,211	2,340
Gain on sale of land	1,503	0
Income from continuing operations	29,703	17,204
Income from discontinued operations	0	10,037
Net income	29,703	27,241
Net income attributable to noncontrolling interest	(3,132)	(3,151)
Net income attributable to controlling interest	26,571	24,090
Dividends to preferred stockholders	(1,368)	(1,368)
Net income available to common stockholders	25,203	22,722
Comprehensive income	30,739	29,592
Comprehensive income attributable to noncontrolling interest	(3,187)	(3,296)
Comprehensive income attributable to controlling interest	$ 27,552	$ 26,296
Basic:
Income from continuing operations (in dollars per share)	$ 0.68	$ 0.39
Income from discontinued operations (in dollars per share)	$ 0	$ 0.28
Net income available to common stockholders (in dollars per share)	$ 0.68	$ 0.67
Weighted average number of common shares outstanding during the period (in shares)	37,003,925	34,027,890
Diluted:
Income from continuing operations (in dollars per share)	$ 0.68	$ 0.39
Income from discontinued operations (in dollars per share)	$ 0	$ 0.28
Net income available to common stockholders (in dollars per share)	$ 0.68	$ 0.67
Weighted average number of common shares outstanding during the period (in shares)	37,092,062	34,151,475
Dividends per common share (in dollars per share)	$ 1.21	$ 1.10