Condensed Consolidated Statements of Equity (Unaudited) - USD ($) $ in Thousands	Total	Class A Common Stock	Common Stock Class A Common Stock	Additional Paid-In Capital	Cumulative Dividends in Excess of Earnings	Total Stockholders’ Equity	Noncontrolling Interest
Beginning balance (in shares) at Dec. 31, 2014			125,087,000
Beginning balance at Dec. 31, 2014	$ 1,476,421		$ 1,251	$ 2,281,932	$ (836,044)	$ 1,447,139	$ 29,282
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Share-based award transactions, net (in shares)			164,000
Share-based award transactions, net	1,914		$ 1	1,913		1,914
Repurchase and cancellation of common stock (in shares)			(48,000)
Repurchase and cancellation of common stock	(1,292)			(1,292)		(1,292)
Dividends declared	(36,873)				(36,309)	(36,309)
Dividends declared							(564)
Net income	6,909				6,804	6,804	105
Ending balance (in shares) at Mar. 31, 2015			125,203,000
Ending balance at Mar. 31, 2015	1,447,079		$ 1,252	2,282,553	(865,549)	1,418,256	28,823
Beginning balance (in shares) at Dec. 31, 2015		127,026,839	127,027,000
Beginning balance at Dec. 31, 2015	1,406,958		$ 1,270	2,328,806	(950,652)	1,379,424	27,534
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock (in shares)			3,418,000
Issuance of common stock	91,269		$ 34	91,235		91,269
Share-based award transactions, net (in shares)			191,000
Share-based award transactions, net	1,803		$ 2	1,801		1,803
Repurchase and cancellation of common stock (in shares)			(70,000)
Repurchase and cancellation of common stock	(1,901)			(1,901)		(1,901)
Redemption of noncontrolling interest and other (in shares)			96,000
Redemption of noncontrolling interest and other	0		$ 1	2,197		2,198	(2,198)
Dividends declared	(39,083)				(38,540)	(38,540)
Dividends declared							(543)
Net income	10,005				9,860	9,860	145
Ending balance (in shares) at Mar. 31, 2016		130,662,036	130,662,000
Ending balance at Mar. 31, 2016	$ 1,469,051		$ 1,307	$ 2,422,138	$ (979,332)	$ 1,444,113	$ 24,938