Restructuring Charges (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2014
Restructuring Cost and Reserve [Line Items]
Restructuring Cost, Total Expected Cost, Low End of Range	$ 5.8
Restructuring Cost, Total Expected Cost, High End of Range	6.3
Restructuring Cost, Severance Costs	5.3
Restructuring Cost, Other Costs, Low End of Range	0.5
Restructuring Cost, Other Costs, High End of Range	1.0
Restructuring and Related Cost, Cost Incurred to Date	4.0
Restructuring and Related Costs, Cost Incurred to Date, Research and Development	3.6
Restructuring and Related Costs, Cost Incurred to Date, General and Administrative	0.4
Restructuring and Related Costs, Cost Incurred to Date, Stock-based Compensation	0.1
Restructuring Reserve	$ 1.1