Commitments and Contingencies Narrative (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018	Dec. 31, 2018	Dec. 31, 2017
Loss Contingencies [Line Items]
Restructuring expenses	$ 173	$ 374	$ 448	$ 464
Restructuring reserve	741	412	741	412	$ 1,630	$ 492
Employee Severance [Member]
Loss Contingencies [Line Items]
Restructuring expenses	$ 200	$ 400	$ 400	$ 500