Income Taxes Domestic Tax Components (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Federal
Current	$ (5,526)	$ 806	$ 723
Deferred	(15,588)	17,378	(2,054)
Investment tax credits	(33)	166	(196)
State
Current	38	33	10
Deferred	2,399	(5,015)	(6,130)
Income Tax (Benefit) Expense	$ (18,710)	$ 13,368	$ (7,647)