CONSOLIDATED STATEMENT OF EQUITY (USD $) In Thousands, except Share data, unless otherwise specified	Total USD ($)	Additional Paid-In Capital USD ($)	Accumulated Deficit USD ($)	Accumulated Other Comprehensive Loss USD ($)	Noncontrolling Interests USD ($)	Class A Common Stock	Class A Common Stock Common Stock USD ($)	Class B Common Stock	Class B Common Stock Common Stock USD ($)
BALANCE at Dec. 31, 2012	$ (100,053)	$ 600,928	$ (713,697)	$ (4,993)	$ 16,897		$ 523		$ 289
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	(41,938)		(41,938)
Issuance of common stock, net of issuance costs	472,400	472,220					180
Issuance of common stock, net of issuance costs (in shares)							18,000,000
Class B Common Stock converted into Class A Common Stock							27		(27)
Class B Common Stock converted into Class A Common Stock (in shares)							2,671,649		(2,671,649)
4.875% Convertible Debentures converted into Class A Common Stock, net of taxes	7,313	7,310					3
4.875% Convertible Debentures converted into Class A Common Stock, net of taxes (in shares)							338,632
Class A Common Stock issued pursuant to employee benefit plans	9,479	9,129			344		6
Class A Common Stock issued pursuant to employee benefit plans (in shares)							558,149
Tax benefit on share based awards	503	503
Distributions to noncontrolling interests	(9,939)				(9,939)
Class A Common Stock sold by variable interest entity, net of taxes	7,008	7,008
Amortization of net periodic pension benefit costs, net of taxes	(116)			(116)
Net income	71,580		71,165		415
BALANCE at Sep. 30, 2013	416,238	1,097,098	(684,470)	(5,109)	7,717		739		263
BALANCE (in shares) at Sep. 30, 2013							73,900,442		26,262,210
BALANCE at Dec. 31, 2013	405,704	1,094,918	(696,996)	(2,553)	9,334		741		260
BALANCE (in shares) at Dec. 31, 2013						74,145,569	74,145,569	26,028,357	26,028,357
Increase (Decrease) in Stockholders' Equity
Dividends declared and paid on Class A and Class B Common Stock	(45,322)		(45,322)
Class B Common Stock converted into Class A Common Stock (in shares)							50,000		(50,000)
Repurchases of Class A Common Stock	(108,476)	(108,438)					(38)
Repurchases of Class A Common Stock (in shares)	(3,900,000)						(3,914,506)
Class A Common Stock issued pursuant to employee benefit plans	9,552	9,550					2
Class A Common Stock issued pursuant to employee benefit plans (in shares)							185,590
Tax benefit on share based awards	1,399	1,399
Distributions to noncontrolling interests	(3,046)				(3,046)
Deconsolidation of variable interest entity	(23,800)	4,518		(546)	(27,772)
Other comprehensive income	406			406
Amortization of net periodic pension benefit costs, net of taxes	121
Net income	118,026		116,834		1,192
BALANCE at Sep. 30, 2014	$ 354,443	$ 1,001,947	$ (625,484)	$ (2,693)	$ (20,292)		$ 705		$ 260
BALANCE (in shares) at Sep. 30, 2014						70,466,653	70,466,653	25,978,357	25,978,357