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, 2015	Dec. 31, 2014	Dec. 31, 2013
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	$ (10,530)	$ 6,990	$ 8,309
Change in unrecognized tax benefits	422	186	199
State income tax, less federal benefit	(6)	972	370
Foreign investment in U.S. property	0	999	1,203
Tax difference on foreign earnings	871	675	(196)
Change in foreign taxes	415	0	(33)
Change in valuation allowance	88,737	0	(100,492)
Tax credits	(346)	0	(361)
Non-deductible expenses	359	289	869
Other, net	(17)	182	192
Income tax provision (benefit)	$ 79,905	$ 10,293	$ (89,940)