Income Taxes Income Tax Expense Detail (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Income Taxes [Abstract]
Current Federal Tax Expense (Benefit)	$ 17,997	$ 34,664	$ 33,364
Current State and Local Tax Expense (Benefit)	(1,495)	454	2,703
Current Income Tax Expense (Benefit)	16,502	35,118	36,067
Deferred Federal Income Tax Expense (Benefit)	(28,020)	(5,291)	5,170
Deferred State and Local Income Tax Expense (Benefit)	843	(164)	2,478
Deferred Income Tax Expense (Benefit)	(27,177)	(5,455)	7,648
Income Tax Expense (Benefit)	$ (10,675)	$ 29,663	$ 43,715