Income Taxes - Benefit (Provision) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Income Tax Benefit (Provision):
Federal	$ 22,255	$ 57,547	$ 45,518
State	6,406	(2,479)	7,268
Foreign	913	2,448	1,124
Income Tax Rate Change		(99,528)
Income tax benefit (provision) before valuation allowance	29,574	(42,012)	53,910
Deferred tax valuation allowance	(28,809)	66,294	$ (53,910)
Income Tax Benefit (Provision)	$ 765	$ 24,282