CONSOLIDATED STATEMENTS OF SHAREHOLDERS' EQUITY (USD $) In Thousands, except Share data, unless otherwise specified	Total	Total Shareholders’ Equity	Common Shares	Additional Paid-In Capital	Accumulated Other Comprehensive Income (Loss)	Retained Earnings	Noncontrolling Interests
Balance at Dec. 31, 2013	$ 1,121,588	$ 704,236	$ 56	$ 665,301	$ 1,132	$ 37,747	$ 417,352
Balance (in Shares) at Dec. 31, 2013	55,643,068		55,643,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Conversion of OP Units to Common Shares by limited partners of the Operating Partnership (in Shares)			99,000
Conversion of OP Units to Common Shares by limited partners of the Operating Partnership	0	2,267		2,267			(2,267)
Issuance of Common Shares, net of issuance costs (in Shares)			4,254,000
Issuance of Common Shares, net of issuance costs	114,641	114,641	4	114,637
Issuance of OP Units to acquire real estate	38,937						38,937
Dividends declared ($0.69 per Common Share)	(42,964)	(40,416)				(40,416)	(2,548)
Vesting of employee Restricted Share and LTIP awards (in Shares)			85,000
Employee and trustee stock compensation, net	6,554	1,586		1,586			4,968
Noncontrolling interest distributions	(211,339)						(211,339)
Noncontrolling interest contributions	35,317						35,317
Balance before adjustment towards comprehensive income (in Shares)			60,081,000
Balance before adjustment towards comprehensive income	1,062,734	782,314	60	783,791	1,132	(2,669)	280,420
Comprehensive (loss) income:
Net income	142,055	61,623				61,623	80,432
Unrealized (loss) income on valuation of swap agreements	(5,189)	(5,969)			(5,969)		780
Reclassification of realized interest on swap agreements	2,734	3,283			3,283		(549)
Comprehensive income	139,600	58,937			(2,686)	61,623	80,663
Balance at Sep. 30, 2014	$ 1,202,334	$ 841,251	$ 60	$ 783,791	$ (1,554)	$ 58,954	$ 361,083
Balance (in Shares) at Sep. 30, 2014	60,081,109		60,081,000