Employee Benefits Amounts recognized in the Consolidated Statements of Financial Position (Details) (USD $) In Millions, unless otherwise specified	Dec. 31, 2013		Dec. 31, 2012
U.K. [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Prepaid benefit cost	$ 549	[1]	$ 301	[1]
Accrued benefit liability	(257)	[2]	(385)	[2]
Accumulated other comprehensive loss	2,036		2,005
Net amount recognized	2,328		1,921
U.S. [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Prepaid benefit cost	0	[1]	0	[1]
Accrued benefit liability	(889)	[2]	(1,253)	[2]
Accumulated other comprehensive loss	1,231		1,591
Net amount recognized	342		338
Other [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Prepaid benefit cost	1	[1]	0	[1]
Accrued benefit liability	(192)	[2]	(314)	[2]
Accumulated other comprehensive loss	405		495
Net amount recognized	$ 214		$ 181

[1] Included in Other non-current assets

[2] Included in Pension, other post retirement, and post employment liabilities