Equity (Tables)

9 Months Ended

Sep. 30, 2023

Equity [Abstract]

Schedule of Equity

	Three Months Ended September 30,
	Common Stock			Other Paid-In Capital		Retained Earnings		Accumulated Other Comprehensive Loss		Treasury Stock			Non- controlling Interests		Total
($ and shares in millions except per share amounts)	Shares	Par Value								Shares	Cost
Balance at July 1, 2022	3,577	$	1,788	$	44,115	$	58,437	$	(4,327)	1,044	$	(56,770)	$	75	$	43,318
Net income attributable to Merck & Co., Inc.	—	—		—		3,248		—		—	—		—		3,248
Other comprehensive loss, net of taxes	—	—		—		—		(416)		—	—		—		(416)
Cash dividends declared on common stock ($0.69 per share)	—	—		—		(1,757)		—		—	—		—		(1,757)
Share-based compensation plans and other	—	—		128		—		—		—	12		—		140
Net income attributable to noncontrolling interests	—	—		—		—		—		—	—		5		5
Distributions attributable to noncontrolling interests	—	—		—		—		—		—	—		(14)		(14)
Balance at September 30, 2022	3,577	$	1,788	$	44,243	$	59,928	$	(4,743)	1,044	$	(56,758)	$	66	$	44,524
Balance at July 1, 2023	3,577	$	1,788	$	44,219	$	54,198	$	(4,900)	1,038	$	(56,612)	$	49	$	38,742
Net income attributable to Merck & Co., Inc.	—	—		—		4,745		—		—	—		—		4,745
Other comprehensive loss, net of taxes	—	—		—		—		(16)		—	—		—		(16)
Cash dividends declared on common stock ($0.73 per share)	—	—		—		(1,861)		—		—	—		—		(1,861)
Treasury stock shares purchased	—	—		—		—		—		4	(466)		—		(466)
Share-based compensation plans and other	—	—		139		—		—		—	12		—		151
Net income attributable to noncontrolling interests	—	—		—		—		—		—	—		5		5
Balance at September 30, 2023	3,577	$	1,788	$	44,358	$	57,082	$	(4,916)	1,042	$	(57,066)	$	54	$	41,300

	Nine Months Ended September 30,
	Common Stock			Other Paid-In Capital		Retained Earnings		Accumulated Other Comprehensive Loss		Treasury Stock			Non- controlling Interests		Total
($ and shares in millions except per share amounts)	Shares	Par Value								Shares	Cost
Balance at January 1, 2022	3,577	$	1,788	$	44,238	$	53,696	$	(4,429)	1,049	$	(57,109)	$	73	$	38,257
Net income attributable to Merck & Co., Inc.	—	—		—		11,502		—		—	—		—		11,502
Other comprehensive loss, net of taxes	—	—		—		—		(314)		—	—		—		(314)
Cash dividends declared on common stock ($2.07 per share)	—	—		—		(5,270)		—		—	—		—		(5,270)
Share-based compensation plans and other	—	—		5		—		—		(5)	351		—		356
Net income attributable to noncontrolling interests	—	—		—		—		—		—	—		6		6
Distributions attributable to noncontrolling interests	—	—		—		—		—		—	—		(13)		(13)
Balance at September 30, 2022	3,577	$	1,788	$	44,243	$	59,928	$	(4,743)	1,044	$	(56,758)	$	66	$	44,524
Balance at January 1, 2023	3,577	$	1,788	$	44,379	$	61,081	$	(4,768)	1,039	$	(56,489)	$	67	$	46,058
Net income attributable to Merck & Co., Inc.	—	—		—		1,591		—		—	—		—		1,591
Other comprehensive loss, net of taxes	—	—		—		—		(148)		—	—		—		(148)
Cash dividends declared on common stock ($2.19 per share)	—	—		—		(5,590)		—		—	—		—		(5,590)
Treasury stock shares purchased	—	—		—		—		—		9	(953)		—		(953)
Share-based compensation plans and other	—	—		(21)		—		—		(6)	376		—		355
Net income attributable to noncontrolling interests	—	—		—		—		—		—	—		12		12
Distributions attributable to noncontrolling interests	—	—		—		—		—		—	—		(25)		(25)
Balance at September 30, 2023	3,577	$	1,788	$	44,358	$	57,082	$	(4,916)	1,042	$	(57,066)	$	54	$	41,300