Income Taxes (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Income Tax Examination [Line Items]
Accrued interest expense	$ 39	$ 58	$ 142	$ 185
Gross liability for unrecognized tax benefits	4,100		4,100
Unrecognized tax benefits that would impact our effective tax rate	2,700		2,700
Interest included in total liability	800		800
Significant increases or decreases for uncertain tax positions	$ 0		$ 0
State and Foreign Tax Authorities | Minimum
Income Tax Examination [Line Items]
Period of statute of limitations (years)			3 years
State and Foreign Tax Authorities | Maximum
Income Tax Examination [Line Items]
Period of statute of limitations (years)			4 years