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, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Income Tax Disclosure [Abstract]
Current, Federal									$ 125	$ 36,733	$ 44,268
Deferred, Federal									70,673	7,459	(426)
Total, Federal									70,798	44,192	43,842
Current, State									1,045	8,187	2,632
Deferred, State									9,453	289	6,847
State, Total									10,498	8,476	9,479
Current Income Tax Expense (Benefit)									1,170	44,920	46,900
Deferred income tax expense									80,126	7,748	6,421
Income Tax Expense (Benefit)	$ 29,204	$ 31,760	$ 10,740	$ 9,592	$ 13,754	$ 12,768	$ 14,285	$ 11,861	$ 81,296	$ 52,668	$ 53,321