Income Taxes (Components Of The Provision For Income Taxes) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Income Tax Disclosure [Abstract]
Federal	$ 74,074	$ 27,470	$ 34,255
State	11,890	9,796	6,896
Total current income tax expense (benefit)	85,964	37,266	41,151
Federal	14,978	39,934	6,695
State	2,704	3,414	929
Total deferred income tax expense (benefit)	17,682	43,348	7,624
Total provision for income taxes	$ 103,646	$ 80,614	$ 48,775