CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) shares in Millions, $ in Millions	12 Months Ended
	Mar. 31, 2022	Mar. 31, 2021	Mar. 31, 2020
Income Statement [Abstract]
Revenues	$ 263,966	$ 238,228	$ 231,051
Cost of sales	(250,836)	(226,080)	(219,028)
Gross profit	13,130	12,148	12,023
Selling, distribution, general, and administrative expenses	(10,537)	(8,849)	(9,182)
Claims and litigation charges, net	(274)	(7,936)	(82)
Goodwill impairment charges	0	(69)	(2)
Restructuring, impairment, and related charges, net	(281)	(334)	(268)
Total operating expenses	(11,092)	(17,188)	(9,534)
Operating income (loss)	2,038	(5,040)	2,489
Other income, net	259	223	12
Equity earnings and charges from investment in Change Healthcare Joint Venture	0	0	(1,108)
Loss on debt extinguishment	(191)	0	0
Interest expense	(178)	(217)	(249)
Income (loss) from continuing operations before income taxes	1,928	(5,034)	1,144
Income tax benefit (expense)	(636)	695	(18)
Income (loss) from continuing operations	1,292	(4,339)	1,126
Loss from discontinued operations, net of tax	(5)	(1)	(6)
Net income (loss)	1,287	(4,340)	1,120
Net income attributable to noncontrolling interests	(173)	(199)	(220)
Net income (loss) attributable to McKesson Corporation	$ 1,114	$ (4,539)	$ 900
Diluted
Continuing operations (in dollars per share)	$ 7.26	$ (28.26)	$ 4.99
Discontinued operations (in dollars per share)	(0.03)	0	(0.04)
Total (in dollars per share)	7.23	(28.26)	4.95
Basic
Continuing operations (in dollars per share)	7.35	(28.26)	5.01
Discontinued operations (in dollars per share)	(0.03)	0	(0.03)
Total (in dollars per share)	$ 7.32	$ (28.26)	$ 4.98
Weighted-average common shares outstanding
Diluted (in shares)	154.1	160.6	181.6
Basic (in shares)	152.3	160.6	180.6