Condensed Consolidated Statements Of Operations (USD $) In Millions, except Per Share data, unless otherwise specified	3 Months Ended				6 Months Ended
	Sep. 30, 2014		Sep. 30, 2013		Sep. 30, 2014		Sep. 30, 2013
Income Statement [Abstract]
Revenues	$ 44,758		$ 32,985		$ 88,816		$ 65,224
Cost of Sales	(41,835)		(30,964)		(83,096)		(61,273)
Gross Profit	2,923		2,021		5,720		3,951
Operating Expenses	(2,135)		(1,300)		(4,244)		(2,560)
Litigation Charges	0		(35)		0		(50)
Total Operating Expenses	(2,135)		(1,335)		(4,244)		(2,610)
Operating Income	788		686		1,476		1,341
Other Income, Net	24		9		44		15
Interest Expense	(99)		(59)		(200)		(118)
Income from Continuing Operations Before Income Taxes	713		636		1,320		1,238
Income Tax Expense	(222)		(213)		(404)		(387)
Income from Continuing Operations	491		423		916		851
Loss from discontinued operations, net of tax	(14)		(19)		(28)		(23)
Net Income	477		404		888		828
Net Income Attributable to Noncontrolling Interests	(8)		0		(16)		0
Net income attributable to McKesson	$ 469		$ 404		$ 872		$ 828
Earnings (Loss) Per Common Share Attributable To McKesson (Diluted)
Continuing operations	$ 2.05	[1]	$ 1.82	[1]	$ 3.83	[1]	$ 3.66	[1]
Discontinued operations	$ (0.06)	[1]	$ (0.08)	[1]	$ (0.12)	[1]	$ (0.10)	[1]
Total	$ 1.99	[1]	$ 1.74	[1]	$ 3.71	[1]	$ 3.56	[1]
Earnings (Loss) Per Common Share Attributable To McKesson (Basic)
Continuing operations	$ 2.08	[1]	$ 1.85	[1]	$ 3.89	[1]	$ 3.73	[1]
Discontinued operations	$ (0.06)	[1]	$ (0.09)	[1]	$ (0.12)	[1]	$ (0.10)	[1]
Total	$ 2.02	[1]	$ 1.76	[1]	$ 3.77	[1]	$ 3.63	[1]
Dividends Declared Per Common Share	$ 0.24		$ 0.24		$ 0.48		$ 0.44
Weighted Average Common Shares
Diluted	235		233		235		232
Basic	232		229		231		228

[1] Certain computations may reflect rounding adjustments.