Retirement Benefit Plans (Details 11) (U.S. and Puerto Rico [Member], USD $) In Millions, unless otherwise specified	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Fair value of U.S. and Puerto Rico pension plan assets
Plan assets at fair market value	$ 275.1	$ 244.9	$ 202.1
Cash and Cash Equivalents [Member]
Fair value of U.S. and Puerto Rico pension plan assets
Plan assets at fair market value	1.4	0.8
U.S. large-cap [Member]
Fair value of U.S. and Puerto Rico pension plan assets
Plan assets at fair market value	52.9	34.1
U.S. small-cap [Member]
Fair value of U.S. and Puerto Rico pension plan assets
Plan assets at fair market value	17.4	12.3
Real Estate [Member]
Fair value of U.S. and Puerto Rico pension plan assets
Plan assets at fair market value	18.7	14.8
International [Member]
Fair value of U.S. and Puerto Rico pension plan assets
Plan assets at fair market value	50.0	43.8
Fixed Income Securities [Member]
Fair value of U.S. and Puerto Rico pension plan assets
Plan assets at fair market value	109.7	113.4
Commodity- linked mutual funds [Member]
Fair value of U.S. and Puerto Rico pension plan assets
Plan assets at fair market value	25.0	25.7
Fair Value Measurements at Reporting Date Using: Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Fair value of U.S. and Puerto Rico pension plan assets
Plan assets at fair market value	1.4	0.8
Fair Value Measurements at Reporting Date Using: Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Cash and Cash Equivalents [Member]
Fair value of U.S. and Puerto Rico pension plan assets
Plan assets at fair market value	1.4	0.8
Fair Value Measurements at Reporting Date Using: Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | U.S. large-cap [Member]
Fair value of U.S. and Puerto Rico pension plan assets
Plan assets at fair market value	0	0
Fair Value Measurements at Reporting Date Using: Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | U.S. small-cap [Member]
Fair value of U.S. and Puerto Rico pension plan assets
Plan assets at fair market value	0	0
Fair Value Measurements at Reporting Date Using: Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Real Estate [Member]
Fair value of U.S. and Puerto Rico pension plan assets
Plan assets at fair market value	0	0
Fair Value Measurements at Reporting Date Using: Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | International [Member]
Fair value of U.S. and Puerto Rico pension plan assets
Plan assets at fair market value	0	0
Fair Value Measurements at Reporting Date Using: Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Fixed Income Securities [Member]
Fair value of U.S. and Puerto Rico pension plan assets
Plan assets at fair market value	0	0
Fair Value Measurements at Reporting Date Using: Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Commodity- linked mutual funds [Member]
Fair value of U.S. and Puerto Rico pension plan assets
Plan assets at fair market value	0	0
Fair Value Measurements at Reporting Date Using: Significant Other Observable Inputs (Level 2) [Member]
Fair value of U.S. and Puerto Rico pension plan assets
Plan assets at fair market value	273.7	244.1
Fair Value Measurements at Reporting Date Using: Significant Other Observable Inputs (Level 2) [Member] | Cash and Cash Equivalents [Member]
Fair value of U.S. and Puerto Rico pension plan assets
Plan assets at fair market value	0	0
Fair Value Measurements at Reporting Date Using: Significant Other Observable Inputs (Level 2) [Member] | U.S. large-cap [Member]
Fair value of U.S. and Puerto Rico pension plan assets
Plan assets at fair market value	52.9	34.1
Fair Value Measurements at Reporting Date Using: Significant Other Observable Inputs (Level 2) [Member] | U.S. small-cap [Member]
Fair value of U.S. and Puerto Rico pension plan assets
Plan assets at fair market value	17.4	12.3
Fair Value Measurements at Reporting Date Using: Significant Other Observable Inputs (Level 2) [Member] | Real Estate [Member]
Fair value of U.S. and Puerto Rico pension plan assets
Plan assets at fair market value	18.7	14.8
Fair Value Measurements at Reporting Date Using: Significant Other Observable Inputs (Level 2) [Member] | International [Member]
Fair value of U.S. and Puerto Rico pension plan assets
Plan assets at fair market value	50.0	43.8
Fair Value Measurements at Reporting Date Using: Significant Other Observable Inputs (Level 2) [Member] | Fixed Income Securities [Member]
Fair value of U.S. and Puerto Rico pension plan assets
Plan assets at fair market value	109.7	113.4
Fair Value Measurements at Reporting Date Using: Significant Other Observable Inputs (Level 2) [Member] | Commodity- linked mutual funds [Member]
Fair value of U.S. and Puerto Rico pension plan assets
Plan assets at fair market value	25.0	25.7
Fair Value Measurements at Reporting Date Using: Significant Unobservable Inputs (Level 3) [Member]
Fair value of U.S. and Puerto Rico pension plan assets
Plan assets at fair market value	0	0
Fair Value Measurements at Reporting Date Using: Significant Unobservable Inputs (Level 3) [Member] | Cash and Cash Equivalents [Member]
Fair value of U.S. and Puerto Rico pension plan assets
Plan assets at fair market value	0	0
Fair Value Measurements at Reporting Date Using: Significant Unobservable Inputs (Level 3) [Member] | U.S. large-cap [Member]
Fair value of U.S. and Puerto Rico pension plan assets
Plan assets at fair market value	0	0
Fair Value Measurements at Reporting Date Using: Significant Unobservable Inputs (Level 3) [Member] | U.S. small-cap [Member]
Fair value of U.S. and Puerto Rico pension plan assets
Plan assets at fair market value	0	0
Fair Value Measurements at Reporting Date Using: Significant Unobservable Inputs (Level 3) [Member] | Real Estate [Member]
Fair value of U.S. and Puerto Rico pension plan assets
Plan assets at fair market value	0	0
Fair Value Measurements at Reporting Date Using: Significant Unobservable Inputs (Level 3) [Member] | International [Member]
Fair value of U.S. and Puerto Rico pension plan assets
Plan assets at fair market value	0	0
Fair Value Measurements at Reporting Date Using: Significant Unobservable Inputs (Level 3) [Member] | Fixed Income Securities [Member]
Fair value of U.S. and Puerto Rico pension plan assets
Plan assets at fair market value	0	0
Fair Value Measurements at Reporting Date Using: Significant Unobservable Inputs (Level 3) [Member] | Commodity- linked mutual funds [Member]
Fair value of U.S. and Puerto Rico pension plan assets
Plan assets at fair market value	$ 0	$ 0