Guarantor Financial Information (Details 3) (USD $) In Thousands, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Condensed consolidating financial statements
Total revenue									$ 423,052	$ 426,428	$ 331,631
Costs and expenses									343,259	294,623	253,687
Operating income (loss)	10,588	21,573	20,837	26,795	9,633	32,878	45,258	44,036	79,793	131,805	77,944
Other income (expense)									(22,682)	14,160	(20,372)
Equity in earnings of subsidiaries									0	0	0
Income tax (expense) benefit									(22,008)	(52,142)	(20,634)
NET INCOME (LOSS)									35,103	93,823	36,938
Issuer
Condensed consolidating financial statements
Total revenue									291,782	280,359	209,046
Costs and expenses									230,033	191,012	166,846
Operating income (loss)									61,749	89,347	42,200
Other income (expense)									(25,495)	6,816	(26,801)
Equity in earnings of subsidiaries									13,557	32,371	27,412
Income tax (expense) benefit									(14,708)	(34,711)	(5,873)
NET INCOME (LOSS)									35,103	93,823	36,938
Guarantor Subsidiaries
Condensed consolidating financial statements
Total revenue									132,690	147,015	123,396
Costs and expenses									114,646	104,557	87,652
Operating income (loss)									18,044	42,458	35,744
Other income (expense)									2,813	7,344	6,429
Equity in earnings of subsidiaries									0	0	0
Income tax (expense) benefit									(7,300)	(17,431)	(14,761)
NET INCOME (LOSS)									13,557	32,371	27,412
Adjustments/Eliminations
Condensed consolidating financial statements
Total revenue									(1,420)	(946)	(811)
Costs and expenses									(1,420)	(946)	(811)
Operating income (loss)									0	0	0
Other income (expense)									0	0	0
Equity in earnings of subsidiaries									(13,557)	(32,371)	(27,412)
Income tax (expense) benefit									0	0	0
NET INCOME (LOSS)									$ (13,557)	$ (32,371)	$ (27,412)