Income Tax (Benefit) Expense Reconciliation (Details) - USD ($) $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2018	Dec. 31, 2018	Dec. 31, 2017
Valuation Allowance [Line Items]
Income tax benefit at U.S. statutory income tax rate		$ (4,609)	$ (4,255)
Effective Income Tax Rate Reconciliation, Change in Enacted Tax Rate, Amount		(82)
Tax Act adjustment			18,100
Valuation allowance		4,562	3,169
Indefinite life intangibles		92	1,173
Change in unrecognized tax benefits		200	500
Other		(158)	384
Income Tax Expense (Benefit)		315	(16,688)
Effective Income Tax Rate Reconciliation, Deduction, Other, Amount		233	490
Effective Income Tax Rate Reconciliation, Tax Exempt Income, Amount	$ 747		0
Effective Income Tax Rate Reconciliation, Nondeductible Expense, Share-based Compensation Cost, Amount		$ (470)	$ 403