Income Taxes - The differences between the U.S. Federal income taxes computed at the statutory rate (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Income Tax Expense (Benefit), Continuing Operations, Income Tax Reconciliation [Abstract]
Statutory federal income tax rate	35.00%	35.00%	35.00%
Statutory federal income tax	$ (9,737)	$ (10,530)	$ 6,990
Change in unrecognized tax benefits	(2,780)	422	186
State income tax, less federal benefit	9	(6)	972
Foreign investment in U.S. property	0	0	999
Tax difference on foreign earnings	225	871	675
Change in foreign taxes	0	415	0
Change in valuation allowance	8,606	88,737	0
Tax credits	0	(346)	0
Non-deductible expenses	180	359	289
Other, net	101	(17)	182
Income tax provision (benefit)	$ (3,396)	$ 79,905	$ 10,293