Consolidated Balance Sheets (Parenthetical) (GBP £) In Millions, except Per Share data, unless otherwise specified	Jun. 30, 2014	Dec. 31, 2013
Statement of Financial Position [Abstract]
Common Stock, Par Value (in USD per share)	£ 0.05	£ 0.05
Common Stock, Shares Authorized	1,000	1,000
Common Stock, Shares, Issued	598.3	597.5
Common Stock, Shares, Outstanding	598.3	597.5
Treasury Stock, Shares	11.4	13.4