Consolidated Statements of Changes in Equity (Unaudited) - USD ($) $ in Thousands	Total	Class A Common Stock [Member]	Additional Paid-in Capital [Member]	Accumulated Other Comprehensive (Loss) Income [Member]	Accumulated Deficit [Member]	Stockholders' Equity [Member]	Non-controlling Interests [Member]
Balance at Dec. 31, 2015	$ 2,505,731	$ 937	$ 3,070,200	$ (32,758)	$ (545,791)	$ 2,492,588	$ 13,143
Shares of class A common stock issued, net	2	2				2
Restricted class A common stock earned	14,190		14,190			14,190
Dividends reinvested	20		276		(256)	20
Deferred directors' compensation	282		282			282
Other comprehensive income (loss)	(13,631)			(13,631)		(13,631)
Net income	193,040				184,921	184,921	8,119
Dividends declared on common stock	(174,678)				(174,678)	(174,678)
Distributions to non-controlling interests	(20,158)						(20,158)
Balance at Sep. 30, 2016	2,504,798	939	3,084,948	(46,389)	(535,804)	2,503,694	1,104
Balance at Dec. 31, 2016	2,493,603	945	3,089,997	(56,202)	(541,137)	2,493,603
Shares of class A common stock issued, net	3	3				3
Restricted class A common stock earned	17,493		17,493			17,493
Issuance of convertible notes	964		964			964
Dividends reinvested	31		327		(296)	31
Deferred directors' compensation	313		313			313
Other comprehensive income (loss)	23,840			23,840		23,840
Net income	159,829				159,741	159,741	88
Contributions from non-controlling interests	6,090						6,090
Dividends declared on common stock	(176,374)				(176,374)	(176,374)
Balance at Sep. 30, 2017	$ 2,525,792	$ 948	$ 3,109,094	$ (32,362)	$ (558,066)	$ 2,519,614	$ 6,178