Income Taxes (Provision For Income Taxes) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Income Tax Disclosure [Abstract]
Federal, Current	$ 480,446	$ 294,509	$ 270,024
State, Current	71,750	40,325	7,148
Federal, Deferred	(127,714)	(168,756)	94,896
State, Deferred	(18,422)	(24,906)	19,508
Income tax provision total	$ 406,060	$ 141,172	$ 391,576