Redeemable Noncontrolling Interests and Noncontrolling Interests - Schedule of Changes in Redeemable Noncontrolling Interests and Noncontrolling Interests (Details) - USD ($) $ in Millions			3 Months Ended						9 Months Ended
	Jun. 02, 2025	Apr. 01, 2025	Dec. 31, 2025	Sep. 30, 2025	Jun. 30, 2025	Dec. 31, 2024	Sep. 30, 2024	Jun. 30, 2024	Dec. 31, 2025	Dec. 31, 2024
Equity, Attributable to Noncontrolling Interest [Roll Forward]
Beginning balance		$ (1,694)	$ (1,355)		$ (1,694)	$ (2,642)		$ (1,599)	$ (1,694)	$ (1,599)
Beginning balance, redeemable noncontrolling interests		0			0				0
Net income attributable to noncontrolling interests			1,250			928			3,244	2,175
Net income attributable to noncontrolling interests			7						12
Payments to noncontrolling interests			(44)			(44)			(135)	(132)
Adjustment to redemption values			(25)						(72)
Other			1			2			0	0
Ending balance			(901)	$ (1,355)		(2,704)	$ (2,642)		(901)	(2,704)
Ending balance, redeemable noncontrolling interests			802						802
PRISM Vision LLC
Equity, Attributable to Noncontrolling Interest [Roll Forward]
Acquisition		25
Core Ventures
Equity, Attributable to Noncontrolling Interest [Roll Forward]
Acquisition	$ 700
Noncontrolling Interests
Equity, Attributable to Noncontrolling Interest [Roll Forward]
Beginning balance		380	384	379	380	375	374	372	380	372
Net income attributable to noncontrolling interests			57	48	47	49	46	45
Payments to noncontrolling interests			(44)	(44)	(47)	(44)	(45)	(43)	(135)	(132)
Adjustment to redemption values			0	0		0	0
Other				1	(1)		0	0
Ending balance			397	384	379	$ 380	$ 375	374	397	$ 380
Noncontrolling Interests \| PRISM Vision LLC
Equity, Attributable to Noncontrolling Interest [Roll Forward]
Acquisition					0			0
Noncontrolling Interests \| Core Ventures
Equity, Attributable to Noncontrolling Interest [Roll Forward]
Acquisition					0			$ 0
Redeemable Noncontrolling Interests
Equity, Attributable to Noncontrolling Interest [Roll Forward]
Beginning balance, redeemable noncontrolling interests		0	777	725	0				0
Net income attributable to noncontrolling interests			7	5	0
Payments to noncontrolling interests			(7)	0	0
Adjustment to redemption values			25	47
Other				0	0
Ending balance, redeemable noncontrolling interests			$ 802	$ 777	725				$ 802
Redeemable Noncontrolling Interests \| PRISM Vision LLC
Equity, Attributable to Noncontrolling Interest [Roll Forward]
Acquisition		$ 25			25
Redeemable Noncontrolling Interests \| Core Ventures
Equity, Attributable to Noncontrolling Interest [Roll Forward]
Acquisition					$ 700

MCKESSON CORP 10-Q