Restructuring and Severance (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Restructuring Cost and Reserve [Line Items]
Restructuring and severance	$ 4,270	$ 0	$ 294
Unpaid severance and related charges	2,400
Severance costs [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and severance	3,900
Other exit costs [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and severance	$ 400