CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS (Unaudited) - USD ($) shares in Millions, $ in Millions	3 Months Ended		6 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Income Statement [Abstract]
Revenues	$ 52,061	$ 49,957	$ 103,112	$ 99,690
Cost of Sales	(49,227)	(47,201)	(97,718)	(94,027)
Gross Profit	2,834	2,756	5,394	5,663
Operating Expenses	(2,009)	(1,886)	(3,936)	(3,821)
Goodwill Impairment Charges	(350)	(290)	(350)	(290)
Restructuring and Asset Impairment Charges	(236)	0	(236)	0
Operating Income	239	580	872	1,552
Other Income, Net	69	23	82	42
Loss from Equity Method Investment in Change Healthcare	(61)	0	(181)	0
Interest Expense	(69)	(78)	(137)	(157)
Income from Continuing Operations Before Income Taxes	178	525	636	1,437
Income Tax Expense	(122)	(200)	(217)	(439)
Income from Continuing Operations	56	325	419	998
Income (Loss) from Discontinued Operations, Net of Tax	0	(1)	2	(114)
Net Income	56	324	421	884
Net Income Attributable to Noncontrolling Interests	(55)	(17)	(111)	(35)
Net Income Attributable to McKesson Corporation	$ 1	$ 307	$ 310	$ 849
Diluted
Continuing operations (in dollars per share)	$ 0.01	$ 1.35	$ 1.46	$ 4.22
Discontinued operations (in dollars per share)	0.00	(0.01)	0.01	(0.50)
Total (in dollars per share)	0.01	1.34	1.47	3.72
Basic
Continuing operations (in dollars per share)	0.01	1.36	1.47	4.27
Discontinued operations (in dollars per share)	0.00	0.00	0.01	(0.51)
Total (in dollars per share)	0.01	1.36	1.48	3.76
Dividends declared per common share (in dollars per share)	$ 0.34	$ 0.28	$ 0.62	$ 0.56
Weighted Average Common Shares
Diluted (in shares)	210	228	211	228
Basic (in shares)	209	226	210	226