Reorganization and Restructuring (Details)	1 Months Ended	3 Months Ended			12 Months Ended
	Jan. 31, 2016 USD ($) director	Dec. 31, 2015 USD ($)	Sep. 30, 2015 USD ($)	Dec. 31, 2014 USD ($)	Dec. 31, 2015 USD ($) position	Dec. 31, 2014 USD ($) position
Reorganization and Restructuring 2015
Restructuring Cost and Reserve [Line Items]
Restructuring charges incurred					$ 11,600,000
Restructuring Reserve [Roll Forward]
Beginning balance	$ 6,300,000				0
Expense		$ 9,600,000	$ 2,000,000		11,600,000
Payments and utilization					(5,300,000)
Foreign currency exchange effects					0
Ending balance		6,300,000		$ 0	6,300,000	$ 0
Reorganization And Restructuring 2014
Restructuring Cost and Reserve [Line Items]
Number of positions eliminated | position						1,700
Restructuring Reserve [Roll Forward]
Beginning balance	1,300,000				21,400,000	$ 0
Expense					1,900,000	21,800,000
Payments and utilization					(20,900,000)	(300,000)
Foreign currency exchange effects					(1,100,000)	(100,000)
Ending balance		1,300,000		21,400,000	1,300,000	21,400,000
Employee Severance
Restructuring Cost and Reserve [Line Items]
Restructuring charges incurred				21,800,000
Employee Severance | Reorganization and Restructuring 2015
Restructuring Reserve [Roll Forward]
Beginning balance	6,300,000				0
Expense					9,800,000
Payments and utilization					(3,500,000)
Foreign currency exchange effects					0
Ending balance		6,300,000		0	6,300,000	0
Employee Severance | Reorganization And Restructuring 2014
Restructuring Cost and Reserve [Line Items]
Estimated restructuring charges		24,000,000			24,000,000
Restructuring Reserve [Roll Forward]
Beginning balance	900,000				21,400,000	0
Expense					(400,000)	21,800,000
Payments and utilization					(19,000,000)	(300,000)
Foreign currency exchange effects					(1,100,000)	(100,000)
Ending balance		900,000		21,400,000	900,000	21,400,000
Contract Terminations | Reorganization and Restructuring 2015
Restructuring Reserve [Roll Forward]
Beginning balance	0				0
Expense					1,600,000
Payments and utilization					(1,600,000)
Foreign currency exchange effects					0
Ending balance		0		0	0	0
Contract Terminations | Reorganization And Restructuring 2014
Restructuring Reserve [Roll Forward]
Beginning balance	400,000				0	0
Expense					2,300,000	0
Payments and utilization					(1,900,000)	0
Foreign currency exchange effects					0	0
Ending balance		400,000		0	400,000	0
Impairments | Reorganization and Restructuring 2015
Restructuring Reserve [Roll Forward]
Beginning balance	$ 0				0
Expense					200,000
Payments and utilization					(200,000)
Foreign currency exchange effects					0
Ending balance		0		$ 0	$ 0	0
Minimum | Reorganization and Restructuring 2015
Restructuring Cost and Reserve [Line Items]
Number of positions eliminated | position					1,000
Cost savings					$ 25,000,000
Minimum | Employee Severance | Executive Leadership and Board of Directors Restructuring
Restructuring Cost and Reserve [Line Items]
Estimated restructuring charges		5,000,000			$ 5,000,000
Maximum | Reorganization and Restructuring 2015
Restructuring Cost and Reserve [Line Items]
Number of positions eliminated | position					1,200
Cost savings					$ 35,000,000
Maximum | Reorganization And Restructuring 2014
Restructuring Cost and Reserve [Line Items]
Cost savings						$ 50,000,000
Maximum | Employee Severance | Executive Leadership and Board of Directors Restructuring
Restructuring Cost and Reserve [Line Items]
Estimated restructuring charges		10,000,000			$ 10,000,000
Director | Employee Severance | Executive Leadership and Board of Directors Restructuring
Restructuring Cost and Reserve [Line Items]
Restructuring charges incurred		$ 1,800,000
Director | Subsequent Event | Employee Severance | Executive Leadership and Board of Directors Restructuring
Restructuring Cost and Reserve [Line Items]
Number of positions eliminated | director	2