Reorganization and Restructuring (Details) $ in Millions	1 Months Ended	3 Months Ended		6 Months Ended		12 Months Ended
	Jan. 31, 2016 USD ($) director	Dec. 31, 2015 USD ($)	Dec. 31, 2014 employee	Jun. 30, 2016 USD ($) employee	Jun. 30, 2015 USD ($)	Dec. 31, 2015 USD ($)	Dec. 31, 2014 USD ($)
2015 Reorganization and Restructuring
Restructuring Cost and Reserve [Line Items]
Reorganization and restructuring costs				$ 4.4		$ 11.6
Positions eliminated across the global workforce | employee				1,000
Cumulative pretax charges				$ 16.0
Restructuring Reserve [Roll Forward]
Restructuring Reserve, beginining balance	$ 6.3			6.3
Expense (benefit)				4.4
Payments and utilization				(7.1)
Foreign currency exchange effects				0.0
Restructuring Reserve, ending balance		$ 6.3		3.6		6.3
2014 Reorganization and Restructuring
Restructuring Cost and Reserve [Line Items]
Positions eliminated across the global workforce | employee			1,700
Expected cost savings						50.0
Restructuring Reserve [Roll Forward]
Expense (benefit)					$ 0.3		$ 21.8
Severance Costs | 2015 Reorganization and Restructuring
Restructuring Reserve [Roll Forward]
Restructuring Reserve, beginining balance	$ 6.3			6.3
Expense (benefit)				2.7
Payments and utilization				(6.2)
Foreign currency exchange effects				0.1
Restructuring Reserve, ending balance		6.3		2.9		6.3
Severance Costs | 2014 Reorganization and Restructuring
Restructuring Reserve [Roll Forward]
Cumulative pretax charges		24.0				24.0
Severance Costs | Director | Executive Leadership and Board of Directors Restructuring
Restructuring Cost and Reserve [Line Items]
Reorganization and restructuring costs		1.8		3.8
Positions eliminated across the global workforce | director	2
Contract Terminations | 2015 Reorganization and Restructuring
Restructuring Reserve [Roll Forward]
Restructuring Reserve, beginining balance	$ 0.0			0.0
Expense (benefit)				0.2
Payments and utilization				(0.2)
Foreign currency exchange effects				0.0
Restructuring Reserve, ending balance		0.0		0.0		0.0
Lease Terminations | 2015 Reorganization and Restructuring
Restructuring Reserve [Roll Forward]
Restructuring Reserve, beginining balance	$ 0.0			0.0
Expense (benefit)				1.5
Payments and utilization				(0.7)
Foreign currency exchange effects				(0.1)
Restructuring Reserve, ending balance		$ 0.0		0.7		$ 0.0
Minimum | 2015 Reorganization and Restructuring
Restructuring Cost and Reserve [Line Items]
Expected cost savings				20.0
Maximum | 2015 Reorganization and Restructuring
Restructuring Cost and Reserve [Line Items]
Expected cost savings				$ 25.0