Income Taxes (Components Of Income Tax Expense) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Federal
Current	$ 44,469us-gaap_CurrentFederalTaxExpenseBenefit	$ 30,266us-gaap_CurrentFederalTaxExpenseBenefit	$ 9,340us-gaap_CurrentFederalTaxExpenseBenefit
Deferred	20,444	(14,970)	6,238
Total	64,913	15,296	15,578
State
Current	4,421	5,234	2,079
Deferred	142	(577)	742
Total	4,563	4,657	2,821
Total, Current	48,890us-gaap_CurrentIncomeTaxExpenseBenefit	35,500us-gaap_CurrentIncomeTaxExpenseBenefit	11,419us-gaap_CurrentIncomeTaxExpenseBenefit
Total, Deferred	20,586us-gaap_DeferredIncomeTaxExpenseBenefit	(15,547)us-gaap_DeferredIncomeTaxExpenseBenefit	6,980us-gaap_DeferredIncomeTaxExpenseBenefit
Income tax expense	$ 69,476us-gaap_IncomeTaxExpenseBenefit	$ 19,953us-gaap_IncomeTaxExpenseBenefit	$ 18,399us-gaap_IncomeTaxExpenseBenefit

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