Income Taxes Income Taxes (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Operating Loss Carryforwards [Line Items]
Unrecognized tax benefits, period increase (decrease)			$ (3,335)	$ (700)
Income tax expense	$ (204)	$ 789	$ 363	$ 1,121
United States
Operating Loss Carryforwards [Line Items]
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent			35.00%