Employee Benefit Plans UK Pension Assets, Fair Value Measurement by Input Level (Details) (Pension Benefits UK Plans, USD $) In Millions, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Defined Benefit Plans and Other Postretirement Benefit Plans [Line Items]
Diversified Growth Assets	$ 172.0	$ 154.7
Fixed Interest and Index-linked Securities	53.0	43.5
Cash Equivalents, at Carrying Value	0.7	7.4
Defined Benefit Plan, Fair Value of Plan Assets	225.7	205.6
Fair Value, Inputs, Level 2
Defined Benefit Plans and Other Postretirement Benefit Plans [Line Items]
Diversified Growth Assets	172.0	154.7
Fixed Interest and Index-linked Securities	0.4	0.9
Cash Equivalents, at Carrying Value	0	0
Defined Benefit Plan, Fair Value of Plan Assets	172.4	155.6
Fair Value, Inputs, Level 3
Defined Benefit Plans and Other Postretirement Benefit Plans [Line Items]
Diversified Growth Assets	0	0
Fixed Interest and Index-linked Securities	0	0
Cash Equivalents, at Carrying Value	0	0
Defined Benefit Plan, Fair Value of Plan Assets	0	0
Fair Value, Inputs, Level 1
Defined Benefit Plans and Other Postretirement Benefit Plans [Line Items]
Diversified Growth Assets	0	0
Fixed Interest and Index-linked Securities	52.6	42.6
Cash Equivalents, at Carrying Value	0.7	7.4
Defined Benefit Plan, Fair Value of Plan Assets	$ 53.3	$ 50.0