Commitments and Contingencies Narrative (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016	Dec. 31, 2016	Dec. 31, 2015
Loss Contingencies [Line Items]
Restructuring expenses	$ 46	$ 539	$ 954	$ 1,271
Restructuring reserve	49	474	49	474	$ 201	$ 81
Employee Severance [Member]
Loss Contingencies [Line Items]
Restructuring expenses	$ 46	$ 539	$ 954	$ 1,271