Consolidated Statements Of Operations (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended
	Mar. 31, 2012	Mar. 31, 2011
Revenues
Rental income	$ 53,217	$ 47,126
Other operating income	3,865	2,409
Total operating revenues	57,082	49,535
Expenses
Property operations and maintenance	14,053	13,513
Real estate taxes	5,761	5,044
General and administrative	7,565	5,772
Acquisition costs	7	42
Depreciation and amortization	10,245	8,625
Total operating expenses	37,631	32,996
Income from operations	19,451	16,539
Other income (expenses)
Interest expense	(8,253)	(7,897)
Interest income	3	18
Equity in income of joint ventures	68	40
Net income	11,269	8,700
Net income attributable to noncontrolling interest	(131)	(440)
Net income attributable to common shareholders	$ 11,138	$ 8,260
Earnings per common share attributable to common shareholders - basic	$ 0.39	$ 0.30
Earnings per common share attributable to common shareholders - diluted	$ 0.39	$ 0.30
Common shares used in basic earnings per share calculation	28,785,663	27,537,278
Common shares used in diluted earnings per share calculation	28,877,736	27,577,435
Dividends declared per common share	$ 0.45	$ 0.45