Interim Consolidated Statement of Income (Unaudited) (USD $) In Millions, except Per Share data	3 Months Ended		9 Months Ended
	Sep. 30, 2011	Sep. 30, 2010	Sep. 30, 2011	Sep. 30, 2010
Consolidated Statement of Income [Abstract]
Sales	$ 12,022	$ 11,125	$ 35,753	$ 33,893
Costs, Expenses and Other
Materials and production	4,352	4,191	12,695	13,956
Marketing and administrative	3,340	3,192	10,029	9,589
Research and development	1,954	2,322	6,048	6,552
Restructuring costs	119	50	773	864
Equity income from affiliates	(161)	(236)	(354)	(417)
Other (income) expense, net	66	1,108	809	995
Total Costs, Expenses and Other	9,670	10,627	30,000	31,539
Income Before Taxes	2,352	498	5,753	2,354
Taxes on Income	628	126	904	872
Net Income	1,724	372	4,849	1,482
Less: Net Income Attributable to Noncontrolling Interests	32	30	89	89
Net Income Attributable to Merck & Co., Inc.	$ 1,692	$ 342	$ 4,760	$ 1,393
Basic Earnings per Common Share Attributable to Merck & Co., Inc. Common Shareholders	$ 0.55	$ 0.11	$ 1.54	$ 0.45
Earnings per Common Share Assuming Dilution Attributable to Merck & Co., Inc. Common Shareholders	$ 0.55	$ 0.11	$ 1.53	$ 0.44
Dividends Declared per Common Share	$ 0.38	$ 0.38	$ 1.14	$ 1.14