Consolidated Statement of Equity Statement - 6 months ended Jun. 30, 2016 - USD ($) $ in Thousands	Total	Common Stock [Member]	Additional Paid-in Capital [Member]	Retained Earnings [Member]	Parent [Member]	Operating Partnership Noncontrolling Interest [Member]	Partially Owned Properties Noncontrolling Interest [Member]	Noncontrolling Interest [Member]
Balance at Dec. 31, 2015	$ 1,076,461	$ 872	$ 1,129,284	$ (109,024)	$ 1,021,132	$ 45,451	$ 9,878	$ 55,329
Net proceeds from sale of common shares	764,205	472	763,733		764,205
Restricted share award grants, net	2,329	2	2,597	(270)	2,329
Purchase of OP Units	(2,129)					(2,129)		(2,129)
Conversion of OP Units		2	3,291		3,293	(3,293)		(3,293)
Dividends/distributions declared	(56,483)			(54,821)	(54,821)	(1,662)		(1,662)
Preferred distributions	(985)			(985)	(985)
Issuance of OP Units in connection with acquisition	2,869		(3,900)		(3,900)	6,869	(100)	6,769
Distributions	(363)						(363)	(363)
Change in market value of Redeemable Noncontrolling Interests in Operating Partnership	(444)		(444)		(444)
Net income	12,608			11,857	11,857	374	377	751
Adjustment for Noncontrolling Interests ownership in Operating Partnership			(4,545)		(4,545)	4,545		4,545
Balance at Jun. 30, 2016	$ 1,798,068	$ 1,348	$ 1,890,016	$ (153,243)	$ 1,738,121	$ 50,155	$ 9,792	$ 59,947