Share-based Compensation Plans (by Share-based Payment Award) (Details)							12 Months Ended																12 Months Ended
	Dec. 31, 2012 SARs and Stock Options		Dec. 31, 2011 SARs and Stock Options		Dec. 31, 2012 Performance Share Awards		Dec. 31, 2012 Portfolio Share Plan - Part A SARs		Dec. 31, 2012 Portfolio Share Plan - Part A SARs Minimum	Dec. 31, 2012 Portfolio Share Plan - Part A SARs Maximum	Dec. 31, 2012 Sharesave Scheme Stock Options		Dec. 31, 2012 Sharesave Scheme Stock Options United Kingdom	Dec. 31, 2012 Sharesave Scheme Stock Options Ireland	Dec. 31, 2012 Sharesave Scheme Stock Options Minimum	Dec. 31, 2012 Sharesave Scheme Stock Options Maximum	Dec. 31, 2012 Stock Purchase Plan Stock Options		Dec. 31, 2012 Stock Purchase Plan Stock Options Minimum	Dec. 31, 2012 Stock Purchase Plan Stock Options Maximum	Dec. 31, 2012 Legacy Plans Stock Options		Dec. 31, 2012 Legacy Plans Stock Options Minimum	Dec. 31, 2012 Legacy Plans Stock Options Maximum	Dec. 31, 2012 Portfolio Share Plan - Part B Performance Share Awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award outstanding (in shares)	18,536,947	[1],[2]	23,398,448	[1]	3,518,138	[2]	17,140,161	[2]			348,891	[2]					784,074	[2]			263,821	[2]			3,518,138	[2]
Award expiration period									5 years	7 years	6 months												7 years	10 years	3 years
Award vesting period							3 years								3 years	5 years			1 year	5 years			3 years	10 years	3 years
Exercise price of common stock, percent													80.00%	75.00%			85.00%

[1] Number of awards are stated in terms of ordinary share equivalents

[2] Number of awards are stated in terms of ordinary share equivalents.