Restructuring - Additional Information (Details) (2014 Restructuring Program [Member], USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2014 position
Restructuring Cost and Reserve [Line Items]
Number of full-time positions eliminated	320
Minimum | Employee Severance [Member]
Restructuring Cost and Reserve [Line Items]
Total expected restructuring cost	22.0
Maximum | Employee Severance [Member]
Restructuring Cost and Reserve [Line Items]
Total expected restructuring cost	24.0