Restructuring - Textual (Detail) (USD $)	3 Months Ended		9 Months Ended		3 Months Ended	9 Months Ended		3 Months Ended		9 Months Ended			3 Months Ended		9 Months Ended			1 Months Ended	9 Months Ended	1 Months Ended	9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2011 Legacy Schering-Plough Program [Member]	Sep. 30, 2012 Legacy Schering-Plough Program [Member]	Sep. 30, 2011 Legacy Schering-Plough Program [Member]	Sep. 30, 2012 Merger Restructuring Program [Member] Positions	Sep. 30, 2011 Merger Restructuring Program [Member] Positions	Sep. 30, 2012 Merger Restructuring Program [Member] Positions	Sep. 30, 2011 Merger Restructuring Program [Member] Positions	Dec. 31, 2011 Merger Restructuring Program [Member]	Sep. 30, 2012 2008 Global Restructuring Program [Member] Positions	Sep. 30, 2011 2008 Global Restructuring Program [Member] Positions	Sep. 30, 2012 2008 Global Restructuring Program [Member] Positions Employees	Sep. 30, 2011 2008 Global Restructuring Program [Member] Positions	Dec. 31, 2011 2008 Global Restructuring Program [Member]	Jul. 31, 2011 Minimum [Member] Merger Restructuring Program [Member]	Sep. 30, 2012 Minimum [Member] Merger Restructuring Program [Member]	Jul. 31, 2011 Maximum [Member] Merger Restructuring Program [Member]	Sep. 30, 2012 Maximum [Member] Merger Restructuring Program [Member]	Sep. 30, 2012 Maximum [Member] 2008 Global Restructuring Program [Member]
Restructuring Cost and Reserve [Line Items]
Additional expected percentage of reduction in total workforce related to Merger Restructuring Program																		12.00%		13.00%
Initial expected percentage of reduction in total workforce related to Merger Restructuring Program										17.00%
Total pretax restructuring costs	$ 163,000,000	$ 275,000,000	$ 741,000,000	$ 1,201,000,000				$ 150,000,000	$ 255,000,000	$ 718,000,000	$ 1,176,000,000		$ 13,000,000	$ 20,000,000	$ 23,000,000	$ 25,000,000
Cumulative restructuring costs incurred to date since program inception										5,800,000,000					1,600,000,000
Positions eliminated since inception of program								20,750		20,750			6,400		6,400
Expected cumulative restructuring costs, pretax																			7,200,000,000		7,500,000,000	2,000,000,000
Percentage estimate of cumulative pre tax costs that will result in cash outlays (primarily from employee separation expense)										Two-thirds					Two-thirds
Percentage estimate of cumulative pretax costs that will be non-cash (primarily from accelerated depreciation of facilities)										One-thirds					One-third
Total number of positions expected to be eliminated															7,200
Number of active employees expected to be eliminated															6,800
Vacant positions eliminated															400
Number of positions eliminated								525	1,300	2,325	2,635		10	110	150	290
Accelerated depreciation for Legacy Schering-Plough Program					2,000,000	4,000,000	18,000,000
Restructuring Reserve						$ 17,000,000		$ 783,000,000		$ 783,000,000		$ 1,195,000,000	$ 95,000,000		$ 95,000,000		$ 126,000,000