CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) shares in Millions, $ in Millions	12 Months Ended
	Mar. 31, 2016	Mar. 31, 2015	Mar. 31, 2014
Income Statement [Abstract]
Revenues	$ 190,884	$ 179,045	$ 137,392
Cost of Sales	(179,468)	(167,634)	(129,040)
Gross Profit	11,416	11,411	8,352
Operating Expenses
Selling, distribution and administrative expenses	(7,276)	(7,901)	(5,388)
Research and development	(392)	(392)	(457)
Restructuring charges	(203)	0	0
Claim and litigation charges	0	(150)	(68)
Total Operating Expenses	(7,871)	(8,443)	(5,913)
Operating Income	3,545	2,968	2,439
Other Income, Net	58	63	32
Interest Expense	(353)	(374)	(300)
Income from Continuing Operations Before Income Taxes	3,250	2,657	2,171
Income Tax Expense	(908)	(815)	(757)
Income from Continuing Operations	2,342	1,842	1,414
Loss from Discontinued Operations, Net of Tax	(32)	(299)	(156)
Net Income	2,310	1,543	1,258
Net (Income) Loss Attributable to Noncontrolling Interests	(52)	(67)	5
Net Income Attributable to McKesson Corporation	$ 2,258	$ 1,476	$ 1,263
Diluted
Continuing operations (in dollars per share)	$ 9.84	$ 7.54	$ 6.08
Discontinued operations (in dollars per share)	(0.14)	(1.27)	(0.67)
Total (in dollars per share)	9.70	6.27	5.41
Basic
Continuing operations (in dollars per share)	9.96	7.66	6.19
Discontinued operations (in dollars per share)	(0.14)	(1.29)	(0.68)
Total (in dollars per share)	$ 9.82	$ 6.37	$ 5.51
Weighted Average Common Shares
Diluted (in shares)	233	235	233
Basic (in shares)	230	232	229