Income Taxes - Income Tax Provision (Benefit) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Current:
United States - Federal	$ 0	$ 18,064	$ 30,738
United States - State	330	331	1,081
France	0	265	5,267
Total current	330	18,660	37,086
Deferred:
United States - Federal	(19,503)	4,686	(6,443)
United States - State	1,280	1,043	(23)
France	0	0	938
Total deferred	(18,223)	5,729	(5,528)
Income tax (benefit) provision	$ (17,893)	$ 24,389	$ 31,558