Consolidated Statements Of Operations (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011
Revenues
Rental income	$ 57,574	$ 48,273	$ 161,857	$ 139,402
Other operating income	4,200	3,824	12,018	8,764
Total operating revenues	61,774	52,097	173,875	148,166
Expenses
Property operations and maintenance	14,319	13,275	40,993	38,410
Real estate taxes	5,629	4,976	16,635	14,532
General and administrative	8,172	6,637	23,707	18,344
Acquisition costs	1,075	2,913	2,382	3,048
Depreciation and amortization	10,427	8,585	30,461	25,164
Total operating expenses	39,622	36,386	114,178	99,498
Income from operations	22,152	15,711	59,697	48,668
Other income (expenses)
Interest expense	(8,350)	(13,760)	(24,914)	(29,739)
Interest income		5	3	31
Equity in income (losses) of joint ventures	335	(512)	608	(408)
Income from continuing operations	14,137	1,444	35,394	18,552
Income from discontinued operations (including gain on disposal of $4,498 in 2012)	4,821	922	6,693	2,595
Net income	18,958	2,366	42,087	21,147
Net income attributable to noncontrolling interest	(151)	(27)	(421)	(811)
Net income attributable to common shareholders	$ 18,807	$ 2,339	$ 41,666	$ 20,336
Earnings per common share attributable to common shareholders-basic
Continuing operations	$ 0.48	$ 0.05	$ 1.20	$ 0.64
Discontinued operations	$ 0.16	$ 0.03	$ 0.23	$ 0.10
Earnings per share-basic	$ 0.64	$ 0.08	$ 1.43	$ 0.74
Earnings per common share attributable to common shareholders-diluted
Continuing operations	$ 0.47	$ 0.05	$ 1.20	$ 0.64
Discontinued operations	$ 0.16	$ 0.03	$ 0.23	$ 0.10
Earnings per share-diluted	$ 0.63	$ 0.08	$ 1.43	$ 0.74
Common shares used in basic earnings per share calculation	29,474,866	27,593,338	29,047,998	27,563,536
Common shares used in diluted earnings per share calculation	29,624,311	27,634,029	29,167,681	27,607,567
Dividends declared per common share	$ 0.45	$ 0.45	$ 1.35	$ 1.35