Restructuring (Restructuring Expense) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Restructuring Cost and Reserve [Line Items]
Restructuring costs	$ 1,906	$ 2,076	$ 2,084	$ 2,315
Severance and other associated costs
Restructuring Cost and Reserve [Line Items]
Restructuring costs	1,906	289	2,084	399
Wind down cost legacy platform
Restructuring Cost and Reserve [Line Items]
Restructuring costs	$ 0	$ 1,787	$ 0	$ 1,916