Income Taxes - Effective Income Tax Expense (Benefit) Reconciliation (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Effective Income Tax Rate Reconciliation, Amount [Abstract]
Statutory amount (computed at 21% in 2019 and 2018 and 35% in 2017)	$ (733)	$ (22,398)	$ (1,449)
Re-measurement of deferred tax assets			(7,451)
Valuation allowance on foreign tax credits	1,081	593	1,514
State income tax, net of federal benefit	991	(1,922)	168
Permanent differences, other	461	1,550	505
Permanent differences, incentive stock options	311	(24)	447
Valuation allowance, other	(166)	10,384	(77)
Uncertain tax provision			1,614
Other	(77)	(416)	188
Total	$ 1,868	$ (12,233)	$ (4,541)
Consolidated effective tax rate	(53.50%)	11.50%	109.70%