Income Taxes (Details 2) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Current tax expense
Federal	$ 106,982	$ 55,008	$ 65,941
State	23,392	11,630	20,232
Foreign	(5,053)	1,744	(233)
Total current	125,321	68,382	85,940
Deferred tax (benefit) expense
Federal	24,893	(4,996)	(112,072)
State	(3,333)	2,792	(34,336)
Total deferred	21,560	(2,204)	(146,408)
Total provision/ (benefit)	146,881	66,178	(60,468)
Percent on pretax income
Federal taxes (as a percent)	35.00%	35.00%	35.00%
State and local income taxes (as a percent)	3.40%	197.10%	3.30%
Permanent differences (as a percent)	2.20%	1263.10%	(20.50%)
Foreign (as a percent)	(1.60%)	16.10%	0.40%
Other miscellaneous items (as a percent)	(1.30%)	(46.50%)	0.20%
Actual effective income tax rate (as a percent)	37.70%	1464.80%	18.40%
Amount based upon pre-tax income
Federal taxes	136,205	1,581	(114,758)
State and local income taxes	13,398	8,905	(10,671)
Permanent differences	8,405	57,058	67,166
Foreign	(6,223)	729	(1,291)
Other miscellaneous items	(4,904)	(2,095)	(914)
Total provision/ (benefit)	146,881	66,178	(60,468)
Reconciliation of liability for unrecognized tax benefits
Balance at the beginning of the period	36,846	46,702
Additions based on current year positions	4,309	5,712
Reductions based on prior year positions		(1,749)
Additions based on prior year positions	3,178
Decreases due to settlements and/or reduction in liabilities	(10,422)	(16,436)
Currency translation adjustments	(39)	2,617
Balance at the end of the period	$ 33,872	$ 36,846	$ 46,702