Income Taxes (Schedule of Components of Income Tax Expense) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Current Income Tax Expense (Benefit), Continuing Operations [Abstract]
Federal	$ 148,495	$ 2,333	$ 0
State and Foreign	18,836	6,489	4,360
Current Income Tax Expense (Benefit)	167,331	8,822	4,360
Deferred Income Tax Expense (Benefit), Continuing Operations [Abstract]
Federal	(77,360)	62,131	62,078
State	(11,154)	7,029	18,666
Deferred Income Tax Expense (Benefit)	(88,514)	69,160	80,744
Tax Expense Relating To Uncertain Tax Positions Including Accrued Interest	7,241	6,266	2,969
Income Tax Expense (Benefit)	$ 86,058	$ 84,248	$ 88,073