Certain Changes in Total Equity (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2013		Mar. 31, 2013 Net Unrealized Gain/(Losses) [Member] Currency Translation Adjustment And Other [Member]		Mar. 31, 2013 Net Unrealized Gain/(Losses) [Member] Derivative Financial Instruments [Member]		Mar. 31, 2013 Net Unrealized Gain/(Losses) [Member] Available For-Sale Securities [Member]		Mar. 31, 2013 Benefit Plans [Member] Actuarial Gains/(Losses) [Member]		Mar. 31, 2013 Benefit Plans [Member] Prior Service (Costs)/ Credits And Other [Member]		Feb. 06, 2013 Zoetis [Member] IPO [Member]
Equity [Abstract]
Noncontrolling interest, ownership percentage by noncontrolling owners													19.80%
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Balance, December 31, 2012	$ (5,953)		$ (177)		$ (88)		$ 163		$ (6,110)		$ 259
Other comprehensive income/(loss)	(202)	[1]	(360)	[1]	(23)	[1]	(13)	[1]	208	[1]	(14)	[1]
Balance, March 31, 2012	$ (6,155)		$ (537)		$ (111)		$ 150		$ (5,902)		$ 245

[1] Amounts do not include foreign currency translation loss of $3 million attributable to noncontrolling interests for the first quarter of 2013.