CONSOLIDATED STATEMENT OF CHANGES IN EQUITY - 9 months ended Sep. 30, 2015 - USD ($) $ in Thousands	Total	Common Stock	Limited Voting Stock	Additional Paid-In Capital	Accumulated Other Comprehensive Loss	Accumulated Deficit	Noncontrolling Interests
Beginning balance at Dec. 31, 2014	$ 1,679,316	$ 111	$ 4	$ 1,842,581	$ (6,166)	$ (443,757)	$ 286,543
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	84,963					58,658	26,305
Other comprehensive income (loss)	(2,539)				(3,684)		1,145
Common dividends declared – $0.5625 per share	(65,504)					(62,696)	(2,808)
Share-based compensation	4,840			4,840
Issuance of 15,690 shares to directors	275			275
Offering costs associated with the issuance of common stock	(209)			(209)
Issuance of 367,257 shares of common stock upon redemption of Operating Partnership units	0	1		6,336			(6,337)
Contribution of capital by noncontrolling interests	2,125						2,125
Distributions to noncontrolling interests	(55,866)						(55,866)
Ending balance at Sep. 30, 2015	$ 1,647,401	$ 112	$ 4	$ 1,853,823	$ (9,850)	$ (447,795)	$ 251,107