Employee Benefit Plans (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Domestic Pension Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 8	$ 6
Interest cost	33	22
Expected return on plan assets	(41)	(30)
Net amortization	11	15
Net periodic benefit cost	11	13
Domestic Other Postretirement Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	3	3
Interest cost	11	8
Expected return on plan assets	(13)	(10)
Net amortization	(1)	1
Net periodic benefit cost	0	2
UK Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	6	5
Interest cost	24	21
Expected return on plan assets	(31)	(25)
Net amortization	13	14
Net periodic benefit cost	$ 12	$ 15