Income Taxes - Provision for income tax (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Current:
Federal	$ 1,088
State	1,408	1,172	594
Foreign	4,121	3,147	735
Total current income taxes	6,617	4,319	1,329
Deferred:
Federal	14,853	12,589
State	10,681	1,992
Foreign	(131)	620	220
Total deferred income taxes	25,403	15,201	220
Total provision for income taxes	$ 32,020	$ 19,520	$ 1,549