CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) shares in Millions, $ in Millions	3 Months Ended
	Jun. 30, 2017	Jun. 30, 2016
Income Statement [Abstract]
Revenues	$ 51,051	$ 49,733
Cost of Sales	(48,491)	(46,826)
Gross Profit	2,560	2,907
Operating Expenses	(1,964)	(1,935)
Operating Expenses	1,927	1,935
Gain on Healthcare Technology Net Asset Exchange	37	0
Operating Income	633	972
Other Income, Net	13	19
Loss from Equity Method Investment in Change Healthcare	(120)	0
Interest Expense	(68)	(79)
Income from Continuing Operations Before Income Taxes	458	912
Income Tax Expense	(95)	(239)
Income from Continuing Operations	363	673
Income (Loss) from Discontinued Operations, Net of Tax	2	(113)
Net Income	365	560
Net Income Attributable to Noncontrolling Interests	(56)	(18)
Net Income Attributable to McKesson Corporation	$ 309	$ 542
Diluted
Continuing operations (in dollars per share)	$ 1.44	$ 2.88
Discontinued operations (in dollars per share)	0.01	(0.50)
Total (in dollars per share)	1.45	2.38
Basic
Continuing operations (in dollars per share)	1.46	2.91
Discontinued operations (in dollars per share)	0.00	(0.50)
Total (in dollars per share)	1.46	2.41
Dividends declared per common share (in dollars per share)	$ 0.28	$ 0.28
Weighted Average Common Shares
Diluted (in shares)	213	228
Basic (in shares)	211	225