Income Taxes (Reconciliation To Effective Rate) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Income Tax Disclosure [Abstract]
Expected federal income tax expense (benefit)	$ 57,727	$ 90,780	$ 413,162
Non taxable investment income	(56,614)	(69,122)	(69,665)
Tax credits	(9,389)	(13,080)	(10,595)
Other	(9)	26	(529)
Total income tax expense (benefit)	$ (8,285)	$ 8,604	$ 332,372