Income Taxes (Details 2) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Current tax expense
Federal	$ 96,490	$ 106,982	$ 55,008
State	14,448	23,392	11,630
Foreign	(3,366)	(5,053)	1,744
Total current	107,572	125,321	68,382
Deferred tax (benefit) expense
Federal	44,874	24,893	(4,996)
State	109	(3,333)	2,792
Total deferred	44,983	21,560	(2,204)
Total provision	152,555	146,881	66,178
Percent on pretax income
Federal taxes (as a percent)	35.00%	35.00%	35.00%
State and local income taxes (as a percent)	1.40%	3.40%	197.10%
Permanent differences (as a percent)	5.30%	2.20%	1263.10%
Foreign (as a percent)	0.20%	(1.60%)	16.10%
Other miscellaneous items (as a percent)	(0.10%)	(1.30%)	(46.50%)
Actual effective income tax rate (as a percent)	41.80%	37.70%	1464.80%
Amount based upon pre-tax income
Federal taxes	127,584	136,205	1,581
State and local income taxes	5,044	13,398	8,905
Permanent differences	19,223	8,405	57,058
Foreign	886	(6,223)	729
Other miscellaneous items	(182)	(4,904)	(2,095)
Total provision	152,555	146,881	66,178
Reconciliation of liability for unrecognized tax benefits
Balance at the beginning of the period	33,872	36,846
Additions based on current year positions	2,465	4,309
Additions based on prior year positions	5,919	3,178
Payments made on account	(13,123)
Decreases due to settlements and/or reduction in reserve	(9,639)
Decreases due to settlements and/or reduction in liabilities		(10,422)
Currency translation adjustments	899	(39)
Balance at the end of the period	$ 20,393	$ 33,872	$ 36,846