Employee Benefits (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011
U.S. Pension Plan
Defined Benefit Plan Disclosure
Interest cost	$ 30	$ 31	$ 60	$ 61
Expected return on plan assets	(32)	(30)	(64)	(60)
Amortization of net actuarial loss	11	7	22	15
Net periodic benefit cost	9	8	18	16
Estimate of contributions to defined benefit pension plans for the current fiscal year	237		237
Contributions made to defined benefit pension plans			52
International Pension Plan
Defined Benefit Plan Disclosure
Service cost	4	5	8	10
Interest cost	66	68	132	134
Expected return on plan assets	(81)	(73)	(161)	(144)
Amortization of net actuarial loss	15	14	29	27
Net periodic benefit cost	4	14	8	27
Estimate of contributions to defined benefit pension plans for the current fiscal year	304		304
Contributions made to defined benefit pension plans			$ 175