Income Taxes - Income Tax Expense (Benefit) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Income Tax Disclosure [Abstract]
Income tax (benefit) expense at United States statutory income tax rate	$ (48)	$ (855)	$ 472	$ (1,348)
Valuation allowance	97	822	(1,234)	1,354
Non-deductible compensation	25	62	34	123
Disposition of subsidiary	(24)	0	(24)	0
State income tax	32	67	58	133
Change in unrecognized tax benefits	71	60	141	130
Indefinite life intangibles	54	24	87	46
Foreign operations subject to different tax rates	(20)	(39)	(17)	(54)
Other	(19)	49	(62)	60
Income tax expense (benefit)	$ 168	$ 190	$ (545)	$ 444