Equity (Tables)

9 Months Ended

Sep. 30, 2014

Equity [Abstract]

Shareholders' Equity

	Common Stock			Other Paid-In Capital			Retained Earnings			Accumulated Other Comprehensive Loss			Treasury Stock					Non- Controlling Interests			Total
($ and shares in millions)	Shares	Par Value											Shares		Cost
Balance at January 1, 2013	3,577	$	1,788	$	40,646		$	39,985		$	(4,682	)	550		$	(24,717	)	$	2,443		$	55,463
Net income attributable to Merck & Co., Inc.	—	—		—			3,623			—			—		—			—			3,623
Cash dividends declared on common stock	—	—		—			(3,835		)	—			—		—			—			(3,835		)
Treasury stock shares purchased	—	—		(500		)	—						129		(5,820		)	—			(6,320		)
Share-based compensation plans and other	—	—		(353		)	—			—			(29	)	1,184			14			845
Other comprehensive loss	—	—		—			—			(16		)	—					—			(16		)
Supera joint venture	—	—		116			—			—			—		—			112			228
Net income attributable to noncontrolling interests	—	—		—			—			—			—		—			79			79
Distributions attributable to noncontrolling interests	—	—		—			—			—			—		—			(61		)	(61		)
Balance at September 30, 2013	3,577	$	1,788	$	39,909		$	39,773		$	(4,698	)	650		$	(29,353	)	$	2,587		$	50,006
Balance at January 1, 2014	3,577	$	1,788	$	40,508		$	39,257		$	(2,197	)	650		$	(29,591	)	$	2,561		$	52,326
Net income attributable to Merck & Co., Inc.	—	—		—			4,604			—			—		—			—			4,604
Cash dividends declared on common stock	—	—		—			(3,872		)	—			—		—			—			(3,872		)
Treasury stock shares purchased	—	—		—			—			—			106		(6,083		)	—			(6,083		)
Share-based compensation plans and other	—	—		(168		)	—			—			(40	)	1,779			46			1,657
Other comprehensive loss	—	—		—			—			(801		)	—		—			—			(801		)
AstraZeneca option exercise	—	—		—			—			—			—		—			(2,400		)	(2,400		)
Net income attributable to noncontrolling interests	—	—		—			—			—			—		—			3			3
Distributions attributable to noncontrolling interests	—	—		—			—			—			—		—			(74		)	(74		)
Balance at September 30, 2014	3,577	$	1,788	$	40,340		$	39,989		$	(2,998	)	716		$	(33,895	)	$	136		$	45,360