Fair Value on a Nonrecurring Basis (Details) (USD $) In Millions, unless otherwise specified	Dec. 31, 2013
Level 1
Fair value assets and liabilities measured on recurring and nonrecurring basis
Fair Value	$ 0
Level 2
Fair value assets and liabilities measured on recurring and nonrecurring basis
Fair Value	1,367.5
Level 3
Fair value assets and liabilities measured on recurring and nonrecurring basis
Fair Value	87.2
Fair Value, Total
Fair value assets and liabilities measured on recurring and nonrecurring basis
Fair Value	$ 1,454.7