Restructuring - Restructuring Activities (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
Restructuring 2017
Restructuring Reserve [Roll Forward]
Restructuring and related cost, incurred cost	$ 6,737
Payments for restructuring	2,453
Restructuring reserve, settled without cash	77
Restructuring Reserve	4,207		$ 4,207
Restructuring 2016
Restructuring Reserve [Roll Forward]
Restructuring and related cost, incurred cost		$ 1,287		$ 14,791
Payments for restructuring			750	12,922
Restructuring reserve, settled without cash				765
Restructuring Reserve	150	1,104	150	1,104	$ 900
Severance and benefit related costs | Restructuring 2017
Restructuring Reserve [Roll Forward]
Restructuring and related cost, incurred cost	5,070
Payments for restructuring	1,639
Restructuring reserve, settled without cash	0
Restructuring Reserve	3,431		3,431
Severance and benefit related costs | Restructuring 2016
Restructuring Reserve [Roll Forward]
Restructuring and related cost, incurred cost				6,939
Payments for restructuring			549	5,835
Restructuring reserve, settled without cash				0
Restructuring Reserve	96	1,104	96	1,104	645
Lease termination costs | Restructuring 2017
Restructuring Reserve [Roll Forward]
Restructuring and related cost, incurred cost	340
Payments for restructuring	264
Restructuring reserve, settled without cash	0
Restructuring Reserve	76		76
Lease termination costs | Restructuring 2016
Restructuring Reserve [Roll Forward]
Restructuring and related cost, incurred cost				969
Payments for restructuring			125	969
Restructuring reserve, settled without cash				0
Restructuring Reserve	0	0	0	0	125
Relocation and other moving costs | Restructuring 2017
Restructuring Reserve [Roll Forward]
Restructuring and related cost, incurred cost	29
Payments for restructuring	29
Restructuring reserve, settled without cash	0
Restructuring Reserve	0		0
Relocation and other moving costs | Restructuring 2016
Restructuring Reserve [Roll Forward]
Restructuring and related cost, incurred cost				569
Payments for restructuring			10	569
Restructuring reserve, settled without cash				0
Restructuring Reserve	0	0	0	0	10
Other restructuring costs | Restructuring 2017
Restructuring Reserve [Roll Forward]
Restructuring and related cost, incurred cost	1,298
Payments for restructuring	521
Restructuring reserve, settled without cash	77
Restructuring Reserve	700		700
Other restructuring costs | Restructuring 2016
Restructuring Reserve [Roll Forward]
Restructuring and related cost, incurred cost				6,314
Payments for restructuring			66	5,549
Restructuring reserve, settled without cash				765
Restructuring Reserve	$ 54	$ 0	$ 54	$ 0	$ 120