Pension Plans (Details) (USD $) In Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2011	Jun. 30, 2010	Jun. 30, 2011	Jun. 30, 2010
UK Pension Benefit [Member]
Components of net periodic benefit cost (income):
Service cost	$ 10	$ 9	$ 19	$ 18
Interest cost	27	24	53	49
Expected return on plan assets	(41)	(33)	(81)	(69)
Amortization of unrecognized prior service gain	(1)	(1)	(2)	(2)
Amortization of unrecognized actuarial loss	7	9	15	18
Net periodic benefit cost	2	8	4	14
Pension Plans (Textuals) [Abstract]
Contributions made to defined benefit pension plans			46	43
Approximate expected contribution to defined pension plan for the full year 2011	92		92
US Pension Benefits [Member]
Components of net periodic benefit cost (income):
Interest cost	11	10	21	20
Expected return on plan assets	(12)	(10)	(23)	(21)
Amortization of unrecognized actuarial loss	1		2	1
Net periodic benefit cost	0		0
Pension Plans (Textuals) [Abstract]
Contributions made to defined benefit pension plans			13	13
Approximate expected contribution to defined pension plan for the full year 2011	30		30
Intl Pension Benefits [Member]
Components of net periodic benefit cost (income):
Service cost	1	2	2	3
Interest cost	2	2	4	4
Expected return on plan assets	(2)	(2)	(4)	(4)
Amortization of unrecognized actuarial loss		1		1
Net periodic benefit cost	1	3	2	4	[1]
Pension Plans (Textuals) [Abstract]
Contributions made to defined benefit pension plans			4	4
Approximate expected contribution to defined pension plan for the full year 2011	$ 7		$ 7

[1] The 2010 Unaudited Condensed Consolidated Statement of Cash Flows has been recast to conform to the new balance sheet presentation. See Note 2 - Basis of Presentation and Significant Accounting Policies for details.