Income Taxes (Schedule Of Components Of Income Tax Expense (Benefit)) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Income Tax Disclosure [Abstract]
Current, Federal									$ 36,733	$ 44,268	$ 29,932
Deferred, Federal									7,459	(426)	(40)
Total, Federal									44,192	43,842	29,892
Current, State									8,187	2,632	4,810
Deferred, State									289	6,847	2,040
State, Total									8,476	9,479	6,850
Current Income Tax Expense (Benefit)									44,920	46,900	34,742
Deferred income tax expense									7,748	6,421	2,000
Income Tax Expense (Benefit)	$ 13,754	$ 12,768	$ 14,285	$ 11,861	$ 14,796	$ 13,587	$ 11,681	$ 13,257	$ 52,668	$ 53,321	$ 36,742