Employee Benefit Plans- Net Periodic Benefit Cost (Credit) (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
Domestic pension benefits
Components of net periodic benefit cost (credit):
Service cost	$ 16	$ 15
Interest cost	43	42
Expected return on assets	(73)	(68)
Other	47	38
Net periodic benefit cost	33	27
Foreign pension benefits
Components of net periodic benefit cost (credit):
Service cost	9	8
Interest cost	10	9
Expected return on assets	(12)	(12)
Other	4	3
Net periodic benefit cost	11	8
Health care benefits
Components of net periodic benefit cost (credit):
Service cost	1	1
Interest cost	2	3
Expected return on assets	(2)	(2)
Other	1	3
Net periodic benefit cost	$ 2	$ 5