CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) shares in Millions, $ in Millions	3 Months Ended		6 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Income Statement [Abstract]
Total Revenues	$ 53,075	$ 52,061	$ 105,682	$ 103,112
Cost of Sales	(50,271)	(49,227)	(100,099)	(97,718)
Gross Profit	2,804	2,834	5,583	5,394
Operating Expenses	(2,033)	(2,009)	(4,063)	(3,936)
Goodwill Impairment Charges	0	(350)	(570)	(350)
Restructuring and Asset Impairment Charges	(82)	(236)	(178)	(236)
Total Operating Expenses	(2,115)	(2,595)	(4,811)	(4,522)
Operating Income	689	239	772	872
Other Income, Net	20	69	60	82
Loss from Equity Method Investment in Change Healthcare	(56)	(61)	(112)	(181)
Interest Expense	(66)	(69)	(127)	(137)
Income from Continuing Operations Before Income Taxes	587	178	593	636
Income Tax Expense	(35)	(122)	(122)	(217)
Income from Continuing Operations	552	56	471	419
Income from Discontinued Operations, Net of Tax	1	0	2	2
Net Income	553	56	473	421
Net Income Attributable to Noncontrolling Interests	(54)	(55)	(112)	(111)
Net Income Attributable to McKesson Corporation	$ 499	$ 1	$ 361	$ 310
Diluted
Continuing operations (in dollars per share)	$ 2.51	$ 0.01	$ 1.79	$ 1.46
Discontinued operations (in dollars per share)	0.00	0.00	0.01	0.01
Total (in dollars per share)	2.51	0.01	1.80	1.47
Basic
Continuing operations (in dollars per share)	2.52	0.01	1.80	1.47
Discontinued operations (in dollars per share)	0.00	0.00	0.01	0.01
Total (in dollars per share)	2.52	0.01	1.81	1.48
Dividends declared per common share (in dollars per share)	$ 0.39	$ 0.34	$ 0.73	$ 0.62
Weighted Average Common Shares
Diluted (in shares)	199	210	201	211
Basic (in shares)	198	209	200	210