Restructuring and Other Compensation (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Restructuring Cost and Reserve [Line Items]
Severance costs	$ 0.5	$ 0.8	$ 1.0
Accrued severance liability	3.3
Employee Severance
Restructuring Cost and Reserve [Line Items]
Severance costs	8.2
Other restructuring costs	0.5
Stock Compensation Plan | Employee Severance
Restructuring Cost and Reserve [Line Items]
Severance costs	3.2
Chief Executive Officer
Restructuring Cost and Reserve [Line Items]
Severance costs	5.1
Chief Financial Officer | RSU and PSU | Employee Severance
Restructuring Cost and Reserve [Line Items]
Severance costs	$ 2.4