Restructuring - Restructuring Activities (Details) - Restructuring 2017 - USD ($) $ in Thousands	3 Months Ended	8 Months Ended
	Mar. 31, 2018	Mar. 31, 2018
Restructuring Reserve [Roll Forward]
Restructuring reserve, start	$ 5,189
Restructuring and related cost, incurred cost	5,244
Restructuring reserve, foreign currency translation gain (loss)	20
Payments for restructuring	4,410	$ 16,500
Restructuring reserve, settled without cash	2,408	12,500
Restructuring reserve, end	3,635	3,635
Severance and benefit related costs
Restructuring Reserve [Roll Forward]
Restructuring reserve, start	3,864
Restructuring and related cost, incurred cost	1,071
Restructuring reserve, foreign currency translation gain (loss)	20
Payments for restructuring	2,305
Restructuring reserve, settled without cash	0
Restructuring reserve, end	2,650	2,650
Lease and contract termination costs
Restructuring Reserve [Roll Forward]
Restructuring reserve, start	650
Restructuring and related cost, incurred cost	678
Restructuring reserve, foreign currency translation gain (loss)	0
Payments for restructuring	793
Restructuring reserve, settled without cash	0
Restructuring reserve, end	535	535
Relocation and other moving costs
Restructuring Reserve [Roll Forward]
Restructuring reserve, start	0
Restructuring and related cost, incurred cost	40
Restructuring reserve, foreign currency translation gain (loss)	0
Payments for restructuring	40
Restructuring reserve, settled without cash	0
Restructuring reserve, end	0	0
Other restructuring costs
Restructuring Reserve [Roll Forward]
Restructuring reserve, start	675
Restructuring and related cost, incurred cost	3,455
Restructuring reserve, foreign currency translation gain (loss)	0
Payments for restructuring	1,272
Restructuring reserve, settled without cash	2,408
Restructuring reserve, end	$ 450	$ 450