CONSOLIDATED STATEMENTS OF EQUITY (DEFICIT) (USD $) In Thousands, except Share data, unless otherwise specified	Class A Common Stock	Class B Common Stock	Additional Paid-In Capital	Accumulated Deficit	Accumulated Other Comprehensive Loss	Noncontrolling Interests	Total
BALANCE at Dec. 31, 2011	$ 520	$ 289	$ 617,375	$ (734,511)	$ (4,848)	$ 9,813	$ (111,362)
BALANCE (in shares) at Dec. 31, 2011	52,022,086	28,933,859
Increase (Decrease) in Stockholders' Equity
Dividends declared and paid on Class A and Class B Common Stock				(123,852)			(123,852)
Class A Common Stock issued pursuant to employee benefit plans	3		5,102				5,105
Class A Common Stock issued pursuant to employee benefit plans (in shares)	309,926
Purchase of assets from entity under common control			(23,638)				(23,638)
Tax benefit on share based awards			271				271
Distributions to noncontrolling interests						(1,142)	(1,142)
Issuance of subsidiary share awards						707	707
Consolidation of variable interest entity						9,050	9,050
Purchase of subsidiary shares from noncontrolling interests			1,818			(1,818)
Other Comprehensive Income					(145)		(145)
Net income				144,666		287	144,953
BALANCE at Dec. 31, 2012	523	289	600,928	(713,697)	(4,993)	16,897	(100,053)
BALANCE (in shares) at Dec. 31, 2012	52,332,012	28,933,859
Increase (Decrease) in Stockholders' Equity
Dividends declared and paid on Class A and Class B Common Stock				(56,767)			(56,767)
Issuance of common stock, net of issuance costs	180		472,733				472,913
Issuance of common stock, net of issuance costs (in shares)	18,000,000
Class B Common Stock converted into Class A Common Stock	29	(29)
Class B Common Stock converted into Class A Common Stock (in shares)	2,905,502	(2,905,502)
Redemption of 3% Convertible Debentures, net of taxes			(5,100)				(5,100)
4.875% Convertible Debentures converted into Class A Common Stock, net of taxes	3		8,599				8,602
4.875% Convertible Debentures converted into Class A Common Stock, net of taxes	338,632
Class A Common Stock issued pursuant to employee benefit plans	6		10,229				10,235
Class A Common Stock issued pursuant to employee benefit plans (in shares)	569,423
Tax benefit on share based awards			521				521
Distributions to noncontrolling interests						(10,256)	(10,256)
Issuance of subsidiary share awards						344	344
Class A Common Stock sold by variable interest entity, net of taxes			7,008				7,008
Other Comprehensive Income					2,440		2,440
Net income				73,468		2,349	75,817
BALANCE at Dec. 31, 2013	741	260	1,094,918	(696,996)	(2,553)	9,334	405,704
BALANCE (in shares) at Dec. 31, 2013	74,145,569	26,028,357
Increase (Decrease) in Stockholders' Equity
Dividends declared and paid on Class A and Class B Common Stock				(61,103)			(61,103)
Class B Common Stock converted into Class A Common Stock	1	(1)
Class B Common Stock converted into Class A Common Stock (in shares)	100,000	(100,000)
Repurchase of Class A Common Stock	(48)		(133,109)				(133,157)
Repurchase of Class A Common Stock (in shares)	(4,876,121)						(4,900,000)
Class A Common Stock issued pursuant to employee benefit plans	2		11,510				11,512
Class A Common Stock issued pursuant to employee benefit plans (in shares)	209,451
Tax benefit on share based awards			1,365				1,365
Distributions to noncontrolling interests						(6,936)	(6,936)
Deconsolidation of variable interest entity			4,518		(546)	(27,773)	(23,801)
Other Comprehensive Income					(3,356)		(3,356)
Net income				212,279		2,836	215,115
BALANCE at Dec. 31, 2014	$ 696	$ 259	$ 979,202	$ (545,820)	$ (6,455)	$ (22,539)	$ 405,343
BALANCE (in shares) at Dec. 31, 2014	69,578,899	25,928,357