Joint Ventures and Other Equity Method Affiliates - Equity Income From Affiliates (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011
Equity Income from Affiliates [Line Items]
Equity income from affiliates	$ 158	$ 161	$ 410	$ 354
Other [Member]
Equity Income from Affiliates [Line Items]
Equity income from affiliates	24	20	23	36
AstraZeneca LP [Member]
Equity Income from Affiliates [Line Items]
Equity income from affiliates	$ 134	$ 141	$ 387	$ 318