Income Taxes (Details) (USD $)	3 Months Ended								12 Months Ended
	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Dec. 31, 2010	Sep. 30, 2010	Jun. 30, 2010	Mar. 31, 2010	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009	Dec. 31, 2008
Income Taxes [Abstract]
Income Tax Reconciliation, Income Tax Expense (Benefit), at Federal Statutory Income Tax Rate									$ 95,489,000	$ 11,728,000	$ 116,043,000
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate									35.00%	35.00%	35.00%
income tax reconciliation, state, local and foreign income taxes, net of federal income tax benefit									9,415,000	4,133,000	10,661,000
Effective Income Tax Reconciliation, state, local and foreign income taxes, net of federal income tax benefit									3.50%	12.30%	3.20%
Income tax reconciliation, reduction for tax positions settled, net of federal income tax benefit									(1,676,000)	(12,324,000)	(37,952,000)
Effective income tax rate reconciliation, reduction for tax positions settled, net of federal income tax benefit									(0.60%)	(36.80%)	(11.40%)
Income Tax Reconciliation, Tax Settlements									7,000,000	13,746,000	5,307,000
Effective Income Tax Rate Reconciliation, Tax Settlements									2.60%	41.00%	1.60%
Income Tax Reconciliation, Other Adjustments									1,065,000	1,761,000	2,797,000
Effective Income Tax Rate Reconciliation, Other Adjustments									0.30%	5.30%	0.80%
Current Income Tax Expense (Benefit)									48,384,000	(3,908,000)	6,198,000
Deferred Income Tax Expense (Benefit)									62,909,000	22,952,000	90,658,000
Income Tax Expense (Benefit)	31,723,000	23,343,000	27,403,000	28,824,000	(16,379,000)	(14,100,000)	15,879,000	33,644,000	111,293,000	19,044,000	96,856,000
Effective Income Tax Rate, Continuing Operations									40.80%	56.80%	29.20%
deferred federal tax asset, net	32,000,000								32,000,000
deferred state tax asset, net	45,000,000								45,000,000
deferred foreign tax asset, net	3,000,000								3,000,000
Tax Benefit from Stock Options Exercised									5,000,000	(1,200,000)	1,800,000
Deferred Tax Assets, Valuation Allowance	(18,232,000)				(18,418,000)				(18,232,000)	(18,418,000)
Unrecognized Tax Benefits	17,091,000				18,034,000				17,091,000	18,034,000	27,700,000	66,902,000
Income Taxes Paid									6,400,000	23,600,000	60,900,000
Unrecognized Tax Benefits that Would Impact Effective Tax Rate	10,700,000								10,700,000
Potential Federal and State unrecognized tax benefit reversal within one year	3,300,000								3,300,000
Unrecognized Tax Benefits, Income Tax Penalties and Interest Accrued	(600,000)								(600,000)
Cash paid for interest, net of federal tax benefit and penalties accrued									3,100,000
deferred tax benefit, ferderal, state and foreign	$ 80,000,000								$ 80,000,000