Income Taxes - Uncertain Tax Positions (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Income Tax Disclosure [Abstract]
Unrecognized tax benefits including interest and penalties	$ 3,900	$ 3,700
Interest and penalties	300	200	$ 200
Schedule reconciliation of gross unrecognized tax benefits
Balance at beginning of period	3,469	3,486	3,490
Additions as a result of tax provisions taken during the current year	305	463	213
Subtractions as a result of tax provisions taken during the prior year	0	(161)	(150)
Foreign currency translation	(93)	(79)	(8)
Lapse in statute of limitations	(67)	(241)	(59)
Settlements	0	0	0
Other	8	1	0
Balance at end of period	3,622	3,469	3,486
Unrecognized tax benefits that would impact effective tax rate	3,600	$ 3,300	$ 3,200
Decrease in unrecognized tax benefits is reasonably possible in next 12 months	$ 100