Income Taxes - Narrative (Details) - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Significant Change in Unrecognized Tax Benefits is Reasonably Possible [Line Items]
Net tax benefit related to reduction in U.S. corporate tax rate		$ 8,400,000
One-time tax expense resulting from transition tax		10,600,000
TCJA remeasurement of deferred taxes	$ 71,000	8,383,000	$ 0
U.S. transition tax	(3,271,000)	10,612,000	0
Net GILTI	347,000	0	0
Foreign withholding tax	$ 5,590,000	$ 0	$ 0
Statutory federal rate	21.00%	35.00%	35.00%
Increase in valuation allowance	$ 567,000	$ 636,000	$ 1,800,000
U.S federal net operating loss carryforwards	$ 86,300,000	67,900,000
Period to utilize the net operating loss carryforwards	17 years
NOL carryforward used in period	$ 11,900,000	9,100,000
Foreign operating loss carryforwards	5,900,000	5,400,000
Foreign operating loss carryforward, no expiration	5,200,000	4,900,000
Foreign operating loss carryforward, expiring	761,000	526,000
Unrecognized tax benefits including interest and penalties	3,300,000	3,100,000
Unrecognized tax benefits that would impact effective rate	3,000,000.0	2,700,000
Reduction of uncertain tax benefits related to certain liabilities for unrecognized tax benefits	307,000
Accrued interest and penalties	373,000	304,000
Income tax penalties and interest expense	69,000	$ 88,000	$ 30,000
Maximum
Significant Change in Unrecognized Tax Benefits is Reasonably Possible [Line Items]
Estimated decrease in unrecognized tax benefit in next twelve months	$ 400,000