Income Taxes - Income Tax Expense (Benefit) (Details) - USD ($)
$ in Thousands
12 Months Ended
Dec. 31, 2016
Dec. 31, 2015
Dec. 31, 2014
Current:      
Federal $ (360) $ (167) $ (7,105)
State (115) (150) (63)
Foreign 12,873 11,439 15,105
Current Income Tax Expense (Benefit) 12,398 11,122 7,937
Deferred:      
Federal 0 3,222 100
State 0 318 0
Foreign 901 48 (2,487)
Deferred Income Tax Expense (Benefit) 901 3,588 (2,387)
Income Taxes $ 13,299 $ 14,710 $ 5,550