McKesson (MCK) 10-K 14 May 14 2014 FY Annual report Financial data

Document_and_Entity_Informatio

Document and Entity Information Document (USD $)	12 Months Ended
In Billions, except Share data, unless otherwise specified	Mar. 31, 2014	Apr. 30, 2014	Sep. 30, 2013
Document And Entity Information [Abstract]	'	'	'
Entity Registrant Name	'McKESSON CORPORATION	'	'
Entity Central Index Key	'0000927653	'	'
Entity Tax Identification Number	'943207296	'	'
Document Type	'10-K	'	'
Current Fiscal Year End Date	'--03-31	'	'
Document Period End Date	31-Mar-14	'	'
Document Fiscal Period Focus	'FY	'	'
Document Fiscal Year Focus	'2014	'	'
Entity Well-known Seasoned Issuer	'Yes	'	'
Entity Voluntary Filers	'No	'	'
Entity Current Reporting Status	'Yes	'	'
Amendment Flag	'false	'	'
Entity Filer Category	'Large Accelerated Filer	'	'
Entity Public Float	'	'	$29.40
Entity Common Stock, Shares Outstanding	'	230,576,753	'

Consolidated_Statements_of_Ope

Consolidated Statements of Operations (USD $)	12 Months Ended
In Millions, except Per Share data, unless otherwise specified	Mar. 31, 2014		Mar. 31, 2013		Mar. 31, 2012
Income Statement [Abstract]	'		'		'
Revenues	$137,609	[1]	$122,069	[1]	$122,321	[1]
Cost of Sales	-129,300		-115,221		-115,919
Gross Profit	8,309		6,848		6,402
Operating Expenses	'		'		'
Selling, distribution and administrative expenses	-5,418		-4,099		-3,727
Research and development	-456		-433		-402
Litigation charges	-68		-72		-149
Gain on business combination	0		81		0
Total Operating Expenses	-5,942		-4,523		-4,278
Operating Income	2,367		2,325		2,124
Other Income, Net	32		34		20
Impairment of an Equity Investment	0		-191		0
Interest Expense	-303		-240		-251
Income from Continuing Operations Before Income Taxes	2,096		1,928		1,893
Income Tax Expense	-742		-581		-514
Income from continuing operations	1,354		1,347		1,379
Income (Loss) from Discontinued Operations, Net of Tax	-96		-9		24
Net Income	1,258		1,338		1,403
Net loss attributable to noncontrolling interests	5		0		0
Net Income Attributable to McKesson	$1,263		$1,338		$1,403
Diluted	'		'		'
Continuing operations	$5.83	[2]	$5.62	[2]	$5.49	[2]
Discontinued operations	($0.42)	[2]	($0.03)	[2]	$0.10	[2]
Total	$5.41	[2]	$5.59	[2]	$5.59	[2]
Basic	'		'		'
Continuing operations	$5.93	[2]	$5.74	[2]	$5.60	[2]
Discontinued operations	($0.42)	[2]	($0.03)	[2]	$0.10	[2]
Total	$5.51	[2]	$5.71	[2]	$5.70	[2]
Weighted Average Common Shares	'		'		'
Diluted	233		239		251
Basic	229		235		246
[1]	Net revenues were attributed to geographic areas based on the customers’ shipment locations.
[2]	Certain computations may reflect rounding adjustments.

Consolidated_Statements_of_Com

Consolidated Statements of Comprehensive Income (USD $)	12 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013	Mar. 31, 2012
Statement of Comprehensive Income [Abstract]	'	'	'
Net Income	$1,258	$1,338	$1,403
Other Comprehensive Income (Loss), Net of Tax	'	'	'
Foreign currency translation adjustments, net of income tax expense (benefit) of $24, ($2) and $2	53	-52	-56
Unrealized losses on cash flow hedges, net of income tax benefit of nil, nil and nil	-6	0	-5
Retirement-related benefit plans, net of income tax expense (benefit) of $29, ($10) and ($9)	36	-18	-21
Other Comprehensive Income (Loss), Net of Tax	83	-70	-82
Comprehensive Income	1,341	1,268	1,321
Comprehensive Income Attributable to Noncontrolling Interests	-16	0	0
Comprehensive Income Attributable to McKesson	1,325	1,268	1,321
Retained Earnings [Member]	'	'	'
Statement of Comprehensive Income [Abstract]	'	'	'
Net Income	$1,258	$1,338	$1,403

Consolidated_Statements_of_Com1

Consolidated Statements of Comprehensive Income (Parenthetical) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013	Mar. 31, 2012
Other Comprehensive Income (Loss), Tax, Parenthetical Disclosures [Abstract]	'	'	'
Foreign currency translation adjustments arising during period, tax expense (benefit) of $24, ($2) and $2	$24	($2)	$2
Unrealized losses on cash flow hedges arising during period, tax benefit of nil, nil and nil	0	0	0
Retirement related benefits plans, net of income tax expense (benefit) of $29, ($10) and ($9)	$29	($10)	($9)

Consolidated_Balance_Sheets

Consolidated Balance Sheets (USD $)	Mar. 31, 2014	Mar. 31, 2013
In Millions, unless otherwise specified
Current Assets	'	'
Cash and cash equivalents	$4,193	$2,456
Receivables, net	14,193	9,975
Inventories, net	13,308	10,335
Prepaid expenses and other	879	404
Total Current Assets	32,573	23,170
Property, Plant and Equipment, Net	2,222	1,321
Goodwill	9,927	6,405
Intangible Assets, Net	5,022	2,270
Other Assets	2,015	1,620
Total Assets	51,759	34,786
Current Liabilities	'	'
Drafts and accounts payable	21,429	16,108
Short-term borrowings	346	0
Deferred revenue	1,236	1,359
Deferred tax liabilities	1,588	1,626
Current portion of long-term debt	1,424	352
Other accrued liabilities	3,478	1,912
Total Current Liabilities	29,501	21,357
Long-Term Debt	8,949	4,521
Other Noncurrent Liabilities	2,991	1,838
Other Commitments and Contingent Liabilities (Note 22)	'	'
Stockholders' Equity	'	'
Preferred stock, $0.01 par value, 100 shares authorized, no shares issued or outstanding	0	0
Common stock, $0.01 par value, 800 shares authorized at March 31, 2014 and 2013, 381 and 376 shares issued at March 31, 2014 and 2013	4	4
Additional Paid-in Capital	6,552	6,078
Retained Earnings	11,453	10,402
Accumulated Other Comprehensive Income (Loss)	-3	-65
Other	23	14
Treasury Shares, at Cost, 150 and 149 at March 31, 2014 and 2013	-9,507	-9,363
Total McKesson Stockholders' Equity	8,522	7,070
Noncontrolling Interests	1,796	0
Total Equity	10,318	7,070
Total Liabilities and Stockholders' Equity	$51,759	$34,786

Consolidated_Balance_Sheets_Pa

Consolidated Balance Sheets (Parenthetical) (USD $)	Mar. 31, 2014	Mar. 31, 2013
Stockholders' Equity	'	'
Preferred stock, par value	$0.01	$0.01
Preferred stock, shares authorized	100,000,000	100,000,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Common stock, par value	$0.01	$0.01
Common stock, shares authorized	800,000,000	800,000,000
Common stock, shares issued	381,000,000	376,000,000
Treasury stock, shares	150,000,000	149,000,000

Consolidated_Statements_of_Sto

Consolidated Statements of Stockholders' Equity (USD $)

Total

Common Stock Shares Issued [Member]

Common Stock [Member]

Additional Paid-in Capital [Member]

Other Capital [Member]

Retained Earnings [Member]

Accumulated Other Comprehensive Income (Loss) [Member]

Treasury Stocks Shares [Member]

Treasury Stock [Member]

Noncontrolling Interest [Member]

In Millions

USD ($)

USD ($)

USD ($)

USD ($)

USD ($)

USD ($)

USD ($)

USD ($)

Beginning Balance, McKesson Stockholders' Equity at Mar. 31, 2011

$7,220

'

$4

$5,339

$10

$8,250

$87

'

($6,470)

'

Beginning Balance, McKesson Stockholders' Equity, Treasury Stock, Shares at Mar. 31, 2011

'

'

'

'

'

'

'

-117

'

'

Beginning Balance, McKesson Stockholders' Equity, Shares at Mar. 31, 2011

'

369

'

'

'

'

'

'

'

'

Issuance of shares under employee plans

143

'

'

167

'

'

'

'

-24

'

Issuance of shares under employee plans, shares

'

4

'

'

'

'

'

-1

'

'

Share-based compensation

154

'

'

154

'

'

'

'

'

'

Tax benefit related to issuance of shares under employee plans

46

'

'

46

'

'

'

'

'

'

Conversion of Celesio convertible bonds

0

'

'

'

'

'

'

'

'

'

Other comprehensive income (loss)

-82

'

'

'

'

'

-82

'

'

'

Other Comprehensive Income (Loss), Net of Tax

-82

'

'

'

'

'

'

'

'

'

Net Income Attributable to McKesson

1,403

'

'

'

'

'

'

'

'

'

Net loss attributable to noncontrolling interests

0

'

'

'

'

'

'

'

'

'

Net Income

1,403

'

'

'

'

1,403

'

'

'

'

Repurchase of common stock

-1,850

[1]

'

'

-140

'

'

'

'

-1,710

'

Repurchase of common stock, Shares

-20

[1],[2],[3]

'

'

'

'

'

'

-20

'

'

Cash dividends declared: $0.92 for 2014, $0.80 for 2013 and $0.80 for 2012 per common share

-202

'

'

'

'

-202

'

'

'

'

Other

-1

'

'

5

-6

'

'

'

'

'

Ending Balance, Noncontrolling Interest at Mar. 31, 2012

'

'

'

'

'

'

'

'

'

0

Ending Balance, McKesson Stockholders' Equity at Mar. 31, 2012

6,831

'

4

5,571

4

9,451

5

'

-8,204

'

Ending Balance, McKesson Stockholders' Equity, Shares at Mar. 31, 2012

'

373

'

'

'

'

'

'

'

'

Ending Balance, McKesson Stockholders' Equity, Treasury Stock, Shares at Mar. 31, 2012

'

'

'

'

'

'

'

-138

'

'

Issuance of shares under employee plans

111

'

'

166

'

'

'

'

-55

'

Issuance of shares under employee plans, shares

'

5

'

'

'

'

'

'

'

'

Share-based compensation

167

'

'

167

'

'

'

'

'

'

Tax benefit related to issuance of shares under employee plans

34

'

'

34

'

'

'

'

'

'

Conversion of Celesio convertible bonds

0

'

'

'

'

'

'

'

'

'

Other comprehensive income (loss)

-70

'

'

'

'

'

-70

'

'

'

Other Comprehensive Income (Loss), Net of Tax

-70

'

'

'

'

'

'

'

'

'

Net Income Attributable to McKesson

1,338

'

'

'

'

'

'

'

'

'

Net loss attributable to noncontrolling interests

0

'

'

'

'

'

'

'

'

'

Net Income

1,338

'

'

'

'

1,338

'

'

'

'

Repurchase of common stock

-1,159

'

'

162

'

'

'

'

-1,321

'

Repurchase of common stock, Shares

-13

[1],[2],[3]

'

'

'

'

'

'

-13

'

'

Retirement of treasury stock

0

'

'

-22

'

-195

'

'

217

'

Retirement of stock repurchased, Shares

'

-2

'

'

'

'

'

'

'

'

Repurchase and retirement of treasury stock, Shares

2

'

'

'

'

'

'

2

'

'

Cash dividends declared: $0.92 for 2014, $0.80 for 2013 and $0.80 for 2012 per common share

-192

'

'

'

'

-192

'

'

'

'

Other

10

'

'

'

10

'

'

'

'

'

Ending Balance, Total Equity at Mar. 31, 2013

7,070

'

'

'

'

'

'

'

'

'

Ending Balance, Noncontrolling Interest at Mar. 31, 2013

0

'

'

'

'

'

'

'

'

0

Ending Balance, McKesson Stockholders' Equity at Mar. 31, 2013

7,070

'

4

6,078

14

10,402

-65

'

-9,363

'

Ending Balance, McKesson Stockholders' Equity, Treasury Stock, Shares at Mar. 31, 2013

-149

'

'

'

'

'

'

-149

'

'

Ending Balance, McKesson Stockholders' Equity, Shares at Mar. 31, 2013

'

376

'

'

'

'

'

'

'

'

Issuance of shares under employee plans

47

'

'

177

'

'

'

'

-130

'

Issuance of shares under employee plans, shares

'

5

'

'

'

'

'

-1

'

'

Share-based compensation

160

'

'

160

'

'

'

'

'

'

Tax benefit related to issuance of shares under employee plans

92

'

'

92

'

'

'

'

'

'

Acquisition of Celesio

1,500

'

'

'

'

'

'

'

'

'

Conversion of Celesio convertible bonds

313

'

'

'

'

'

'

'

'

'

Other comprehensive income (loss)

'

'

'

'

'

'

62

'

'

21

Other Comprehensive Income (Loss), Net of Tax

83

'

'

'

'

'

'

'

'

'

Net Income Attributable to McKesson

1,263

'

'

'

'

1,263

'

'

'

'

Net loss attributable to noncontrolling interests

5

'

'

'

'

'

'

'

'

5

Net Income

1,258

'

'

'

'

1,258

'

'

'

'

Repurchase of common stock

0

[1]

'

'

14

'

'

'

'

-14

'

Repurchase of common stock, Shares

0

[1],[2],[3]

'

'

'

'

'

'

0

'

'

Cash dividends declared: $0.92 for 2014, $0.80 for 2013 and $0.80 for 2012 per common share

-214

'

'

'

'

-214

'

'

'

'

Other

9

'

'

-2

9

2

'

'

'

'

Ending Balance, Total Equity at Mar. 31, 2014

10,318

'

'

'

'

'

'

'

'

'

Ending Balance, Noncontrolling Interest at Mar. 31, 2014

1,796

'

'

'

'

'

'

'

'

1,796

Ending Balance, McKesson Stockholders' Equity at Mar. 31, 2014

8,522

'

4

6,552

23

11,453

-3

'

-9,507

'

Ending Balance, McKesson Stockholders' Equity, Treasury Stock, Shares at Mar. 31, 2014

-150

'

'

'

'

'

'

-150

'

'

Ending Balance, McKesson Stockholders' Equity, Shares at Mar. 31, 2014

'

381

'

'

'

'

'

'

'

'

Beginning Balance, Total Equity at Dec. 31, 2013

'

'

'

'

'

'

'

'

'

'

Conversion of Celesio convertible bonds

313

'

'

33

'

'

'

'

'

280

Net Income Attributable to McKesson

371

'

'

'

'

'

'

'

'

'

Net loss attributable to noncontrolling interests

[4]

5

'

'

'

'

'

'

'

'

'

Net Income

366

'

'

'

'

'

'

'

'

'

Ending Balance, Noncontrolling Interest at Mar. 31, 2014

1,796

'

'

'

'

'

'

'

'

1,796

Ending Balance, Total Equity at Mar. 31, 2014

10,318

'

'

'

'

'

'

'

'

'

Ending Balance, McKesson Stockholders' Equity at Mar. 31, 2014

$8,522

'

$4

$6,552

'

'

'

'

'

'

Ending Balance, McKesson Stockholders' Equity, Treasury Stock, Shares at Mar. 31, 2014

-150

'

'

'

'

'

'

'

'

'

[1]

This table does not include shares tendered to satisfy the exercise price in connection with cashless exercises of employee stock options or shares tendered to satisfy tax withholding obligations in connection with employee equity awards.

[2]

The number of shares purchased reflects rounding adjustments.

[3]

All of the shares purchased were part of the publicly announced programs.

[4]

Primarily represents the noncontrolling shareholdersb portion of net loss from Celesio.

Consolidated_Statements_of_Sto1

Consolidated Statements of Stockholders' Equity (Parentheticals) (USD $)	12 Months Ended
	Mar. 31, 2014	Mar. 31, 2013	Mar. 31, 2012
Statement of Stockholders' Equity [Abstract]	'	'	'
Cash dividends declared per common share	$0.92	$0.80	$0.80

Consolidated_Statements_of_Cas

Consolidated Statements of Cash Flows (USD $)	12 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2014		Mar. 31, 2013		Mar. 31, 2012
Operating Activities	'		'		'
Net Income	$1,258		$1,338		$1,403
Adjustments to reconcile to net cash provided by operating activities:	'		'		'
Depreciation	186		133		127
Amortization	518		397		366
Other deferred taxes	16		608		175
Share-based compensation expense	160		167		154
Gain on business combination	0		-81		0
Impairment of an equity investment	0		191		0
Net LIFO expense	311		13		11
Other non-cash items	130		90		93
Changes in operating assets and liabilities, net of acquisitions:	'		'		'
Receivables	-885		315		-768
Inventories	-1,201		-60		-882
Drafts and accounts payable	2,412		-127		2,037
Deferred revenue	-36		-1		97
Taxes	218		-86		19
Litigation charges	68		72		149
Litigation settlement payments	-105		-483		-26
Other	86		-3		-5
Net cash provided by operating activities	3,136		2,483		2,950
Investing Activities	'		'		'
Property acquisitions	-274	[1]	-232	[1]	-221	[1]
Capitalized software expenditures	-141		-153		-177
Acquisitions, net of cash and cash equivalents acquired	-4,634		-1,873		-1,051
Proceeds from sale of business	97		0		0
Other	-94		49		-53
Net cash used in investing activities	-5,046		-2,209		-1,502
Financing Activities	'		'		'
Proceeds from short-term borrowings	6,145		2,225		400
Repayments of short-term borrowings	-6,122		-2,625		0
Proceeds from issuances of long-term debt	4,114		1,798		0
Repayments of long-term debt	-356		-1,143		-430
Common stock transactions:	'		'		'
Issuances	177		166		167
Share repurchases, including shares surrendered for tax withholding	-130		-1,214		-1,874
Dividends paid	-214		-194		-195
Other	5		31		27
Net cash used in financing activities	3,619		-956		-1,905
Effect of exchange rate changes on cash and cash equivalents	28		-11		-6
Net decrease in cash and cash equivalents	1,737		-693		-463
Cash and cash equivalents at beginning of year	2,456		3,149		3,612
Cash and cash equivalents at end of year	4,193		2,456		3,149
Cash paid for:	'		'		'
Interest	255		207		228
Income taxes, net of refunds	508		55		337
Non-cash item:	'		'		'
Fair value of debt assumed on acquisition	-2,312		-635		0
Conversion of Celesio convertible bonds	$313		$0		$0
[1]	Long-lived assets consist of property, plant and equipment.

Significant_Accounting_Policie

Significant Accounting Policies	12 Months Ended
	Mar. 31, 2014
Accounting Policies [Abstract]	'
Significant Accounting Policies	'
	Significant Accounting Policies
	Nature of Operations: McKesson Corporation (“McKesson,” the “Company,” the “Registrant” or “we” and other similar pronouns) delivers pharmaceuticals, medical supplies and healthcare information technology that make healthcare safer while reducing costs. We conduct our business through two operating segments, McKesson Distribution Solutions and McKesson Technology Solutions, as further described in Financial Note 25, “Segments of Business.”
	Basis of Presentation: The consolidated financial statements and accompanying notes are prepared in accordance with U. S. generally accepted accounting principles (“GAAP”). The consolidated financial statements of McKesson include the financial statements of all wholly-owned subsidiaries and majority-owned or controlled companies. We also evaluate our ownership, contractual and other interests in entities to determine if they are variable interest entities (“VIEs”), if we have a variable interest in those entities and the nature and extent of those interests. These evaluations are highly complex and involve judgment and the use of estimates and assumptions based on available historical information and management’s judgment, among other factors. Based on our evaluations, if we determine we are the primary beneficiary of such VIEs we consolidate such entities into our financial statements. Refer to Financial Note 15, “Variable Interest Entities” for more information on these VIEs. Investments in business entities in which we do not have control, but have the ability to exercise significant influence over operating and financial policies, are accounted for using the equity method and our proportionate share of income or loss is recorded in other income, net. Equity investments in non-publicly traded entities are primarily accounted for using the cost method. Intercompany transactions and balances have been eliminated.
	Fiscal Period: The Company’s fiscal year begins on April 1 and ends on March 31. Unless otherwise noted, all references to a particular year shall mean the Company’s fiscal year.
	Reclassifications: Certain prior year amounts have been reclassified to conform to the current year presentation.
	Use of Estimates: The preparation of financial statements in conformity with U.S. GAAP requires that we make estimates and assumptions that affect the reported amounts in the consolidated financial statements and accompanying notes. Actual amounts could differ from those estimated amounts.
	Cash and Cash Equivalents: All highly liquid debt instruments purchased with original maturity of three months or less at the date of acquisition are included in cash and cash equivalents.
	Cash equivalents, which are available-for-sale, are carried at fair value. Cash equivalents are primarily invested in AAA rated prime and U.S. government money market funds denominated in U.S. dollars, AAA rated prime money market funds denominated in Euros, overnight repurchase agreements collateralized by U.S. Treasury bonds, Canadian government securities and/or securities that are guaranteed or sponsored by the U.S. government and an AAA rated prime money market fund denominated in British pound sterling.
	The remaining cash and cash equivalents are deposited with several financial institutions. Deposits at U.S. banks exceed the amount insured by the Federal Deposit Insurance Corporation. We mitigate the risk of our short-term investment portfolio by depositing funds with reputable financial institutions and monitoring risk profiles and investment strategies of money market funds. Within the Celesio operations, the majority of deposits are placed in Germany with only banks that are part of deposit protection programs.
	Restricted Cash: Cash that is subject to legal restrictions or is unavailable for general operating purposes is classified as restricted cash and is included within prepaid expenses and other in the consolidated balance sheets. At March 31, 2014 and 2013 restricted cash was not material.
	Marketable Securities Available-for-Sale: We carry our marketable securities, which are available-for-sale, at fair value and they are included in prepaid expenses and other in the consolidated balance sheets. The unrealized gains and losses, net of the related tax effect, computed in marking these securities to market have been reported within stockholders’ equity. At March 31, 2014 and 2013 marketable securities were not material.
	In determining whether an other-than-temporary decline in market value has occurred, we consider the duration that, and extent to which, the fair value of the investment is below its cost, the financial condition and future prospects of the issuer or underlying collateral of a security, and our intent and ability to retain the security in order to allow for an anticipated recovery in fair value. Other-than-temporary declines in fair value from amortized cost for available-for-sale equity securities that we intend to sell or would more likely than not be required to sell before the expected recovery of the amortized cost basis are charged to other income (expense) in the period in which the loss occurs.
	Concentrations of Credit Risk and Receivables: Our trade receivables are subject to a concentration of credit risk with customers primarily in our Distribution Solutions segment. During 2014, sales to our ten largest customers accounted for approximately 48% of our total consolidated revenues. Sales to our largest customer, CVS Caremark Corporation ("CVS"), accounted for approximately 16% of our total consolidated revenues. At March 31, 2014, trade accounts receivable from our ten largest customers were approximately 32% of total trade accounts receivable. Accounts receivable from CVS were approximately 12% of total trade accounts receivable. As a result, our sales and credit concentration is significant. We also have agreements with group purchasing organizations (“GPOs”), each of which functions as a purchasing agent on behalf of member hospitals, pharmacies and other healthcare providers. The accounts receivables balances are with individual members of the GPOs. A default in payment, a material reduction in purchases from these or any other large customers, or the loss of a large customer or customer groups could have a material adverse impact on our financial condition, results of operations and liquidity. In addition, trade receivables are subject to a concentration of credit risk with customers in the institutional, retail and healthcare provider sectors, which can be affected by a downturn in the economy and changes in reimbursement policies. This credit risk is mitigated by the size and diversity of the customer base as well as its geographic dispersion. We estimate the receivables for which we do not expect full collection based on historical collection rates and ongoing evaluations of the creditworthiness of our customers. An allowance is recorded in our consolidated financial statements for these amounts.
	Financing Receivables: We assess and monitor credit risk associated with financing receivables, namely lease and notes receivables, through regular review of our collection experience in determining our allowance for loan losses. On an ongoing basis, we also evaluate credit quality of our financing receivables utilizing aging of receivables and write-offs, as well as considering existing economic conditions, to determine if an allowance is necessary. Financing receivables are derecognized if legal title to them has been transferred and all related risks and rewards incidental to ownership have passed to the buyer.  As of March 31, 2014 and 2013, financing receivables and the related allowance were not material to our consolidated financial statements.
	Inventories: We report inventories at the lower of cost or market (“LCM”). Inventories for our Distribution Solutions segment consist of merchandise held for resale. For our Distribution Solutions segment, the majority of the cost of domestic inventories is determined using the last-in, first-out (“LIFO”) method. The majority of the cost of inventories held in foreign locations is based on weighted average purchase prices using the first-in, first-out method. Technology Solutions segment inventories consist of computer hardware with cost generally determined by the standard cost method, which approximates average cost. Rebates, cash discounts, and other incentives received from vendors are accounted for as a reduction in the cost of inventory and are recognized when the inventory is sold.
	The LIFO method was used to value approximately 67% and 80% of our inventories at March 31, 2014 and 2013. If we had used the FIFO method of inventory valuation, which approximates current replacement costs, inventories would have been approximately $431 million and $120 million higher than the amounts reported at March 31, 2014 and 2013, respectively. These amounts are equivalent to our LIFO reserves. Our LIFO valuation amount includes both pharmaceutical and non-pharmaceutical products. In 2014, 2013 and 2012, we recognized net LIFO expense of $311 million, $13 million and $11 million within our consolidated statements of operations. A LIFO expense is recognized when the net effect of price increases on branded pharmaceuticals and non-pharmaceutical products held in inventory exceeds the impact of price declines and shifts towards generic pharmaceuticals, including the effect of branded pharmaceutical products that have lost market exclusivity. A LIFO credit is recognized when the net effect of price declines and shifts towards generic pharmaceuticals exceeds the impact of price increases on branded pharmaceuticals and non-pharmaceutical products held in inventory.
	We believe that the average inventory costing method provides a reasonable estimation of the current cost of replacing inventory (i.e., “market”). As such, our LIFO inventory is valued at the lower of LIFO or market. Primarily due to historical net deflation in our pharmaceutical inventories, pharmaceutical inventories at LIFO were $60 million higher than market as of March 31, 2013. As a result, we recorded a LCM credit of $60 million and $16 million in 2014 and 2013 within our consolidated statements of operations to adjust our LIFO inventories to market.
	Shipping and Handling Costs: We include costs to warehouse, pick, pack and deliver inventory to our customers in selling, distribution and administrative expenses.
	Property, Plant and Equipment: We state our property, plant and equipment at cost and depreciate them under the straight-line method at rates designed to distribute the cost of properties over estimated service lives ranging from one to thirty years.
	Goodwill: Goodwill is tested for impairment on an annual basis in the fourth quarter or more frequently if indicators for potential impairment exist. Impairment testing is conducted at the reporting unit level, which is generally defined as a component — one level below our Distribution Solutions and Technology Solutions operating segments, for which discrete financial information is available and segment management regularly reviews the operating results of that unit. Components that have essentially similar operations, products, services, customers and operating margins are aggregated as a single reporting unit.
	The first step in goodwill testing requires us to compare the estimated fair value of a reporting unit to its carrying value. This step may be performed utilizing either a qualitative or quantitative assessment. If the carrying value of the reporting unit is lower than its estimated fair value, no further evaluation is necessary. If the carrying value of the reporting unit is higher than its estimated fair value, the second step must be performed to measure the amount of impairment loss. Under the second step, the implied fair value of goodwill is calculated in a hypothetical analysis by subtracting the fair value of all assets and liabilities of the reporting unit, including any unrecognized intangible assets, from the fair value of the reporting unit calculated in the first step of the impairment test. If the carrying value of goodwill for the reporting unit exceeds the implied fair value of goodwill, an impairment charge is recorded for that excess.
	To estimate the fair value of our reporting units, we use a combination of the market approach and the income approach. Under the market approach, we estimate fair value by comparing the business to similar businesses or guideline companies whose securities are actively traded in public markets. Under the income approach, we use a discounted cash flow model in which cash flows anticipated over several periods, plus a terminal value at the end of that time horizon, are discounted to their present value using an appropriate expected rate of return. The discount rate used for cash flows reflects capital market conditions and the specific risks associated with the business. In addition, we compare the aggregate of the reporting units’ fair value to the Company’s market capitalization as a further corroboration of the fair values. The testing requires a complex series of assumptions and judgment by management in projecting future operating results, selecting guideline companies for comparisons and assessing risks. The use of alternative assumptions and estimates could affect the fair values and change the impairment determinations.
	Intangible Assets: Currently all of our intangible assets are subject to amortization and are amortized based on the pattern of their economic consumption or on a straight-line basis over their estimated useful lives, ranging from one to thirty-eight years. We review intangible assets for impairment whenever events or changes in circumstances indicate that the carrying value of the assets may not be recoverable. Determination of recoverability is based on the lowest level of identifiable estimated future undiscounted cash flows resulting from use of the asset and its eventual disposition. Measurement of any impairment loss is based on the excess of the carrying value of the asset over its fair market value.
	Capitalized Software Held for Sale: Development costs for software held for sale, which primarily pertain to our Technology Solutions segment, are capitalized once a project has reached the point of technological feasibility. Completed projects are amortized after reaching the point of general availability using the straight-line method based on an estimated useful life of approximately three years. At each balance sheet date, or earlier if an indicator of an impairment exists, we evaluate the recoverability of unamortized capitalized software costs based on estimated future undiscounted revenues net of estimated related costs over the remaining amortization period.
	Capitalized Software Held for Internal Use: We capitalize costs of software held for internal use during the application development stage of a project and amortize those costs over their estimated useful lives ranging from one to ten years. As of March 31, 2014 and 2013, capitalized software held for internal use was $514 million and $465 million, net of accumulated amortization of $1,004 million and $1,011 million, and was included in other assets in the consolidated balance sheets.
	Insurance Programs: Under our insurance programs, we seek to obtain coverage for catastrophic exposures as well as those risks required to be insured by law or contract. It is our policy to retain a significant portion of certain losses primarily related to workers’ compensation and comprehensive general, product and vehicle liability. Provisions for losses expected under these programs are recorded based upon our estimate of the aggregate liability for claims incurred as well as for claims incurred but not yet reported. Such estimates utilize certain actuarial assumptions followed in the insurance industry.
	Revenue Recognition:
	Distribution Solutions
	Revenues for our Distribution Solutions segment are recognized when product is delivered and title passes to the customer or when services have been rendered and there are no further obligations to the customer.
	Revenues are recorded net of sales returns, allowances, rebates and other incentives. Our sales return policy generally allows customers to return products only if they can be resold for value or returned to suppliers for full credit. Sales returns are accrued based on estimates at the time of sale to the customer. Sales returns from customers were approximately $1.9 billion in 2014, $1.9 billion in 2013 and $1.6 billion in 2012. Taxes collected from customers and remitted to governmental authorities are presented on a net basis; that is, they are excluded from revenues.
	Revenues for our Distribution Solutions segment include large volume sales of pharmaceuticals primarily to a limited number of large customers who warehouse their own product. We order bulk product from the manufacturer, receive and process the product primarily through our central distribution facility and deliver the bulk product (generally in the same form as received from the manufacturer) directly to our customers’ warehouses. We also record revenues for direct store deliveries from most of these same customers. Direct store deliveries are shipments from the manufacturer to our customers of a limited category of products that require special handling. We assume the primary liability to the manufacturer for these products.
	Revenues are recorded gross when we are the primary party obligated in the transaction, take title to and possession of the inventory, are subject to inventory risk, have latitude in establishing prices, assume the risk of loss for collection from customers as well as delivery or return of the product, are responsible for fulfillment and other customer service requirements, or the transactions have several but not all of these indicators.
	Our Distribution Solutions segment also engages in multiple-element arrangements, which may contain a combination of various products and services. Revenue from a multiple element arrangement is allocated to the separate elements based on their relative selling price and recognized in accordance with the revenue recognition criteria applicable to each element. Relative selling price is determined based on vendor-specific objective evidence (“VSOE”) of selling price, if available, third-party evidence (“TPE”), if VSOE of selling price is not available, or estimated selling price (“ESP”), if neither VSOE of selling price nor TPE is available.
	Technology Solutions
	Revenues for our Technology Solutions segment are generated primarily by licensing software and software systems (consisting of software, hardware and maintenance support), and providing claims processing, outsourcing and professional services. Software and hardware are included in product revenue, while maintenance support among other services are included in service revenue. Revenue for this segment is recognized as follows:
	Software systems are marketed under information systems agreements as well as service agreements. Perpetual software arrangements are recognized at the time of delivery or under the percentage-of-completion method if the arrangements require significant production, modification or customization of the software. Contracts accounted for under the percentage-of-completion method are generally measured based on the ratio of labor hours incurred to date to total estimated labor hours to be incurred. Changes in estimates to complete and revisions in overall profit estimates on these contracts are charged to earnings in the period in which they are determined. We accrue for contract losses if and when the current estimate of total contract costs exceeds total contract revenue.
	Revenue from time-based software license agreements is recognized ratably over the term of the agreement. Software implementation fees are recognized as the work is performed or under the percentage-of-completion method. Maintenance and support agreements are marketed under annual or multi-year agreements and are recognized ratably over the period covered by the agreements. Hardware revenues are generally recognized upon delivery.
	Subscription, content and transaction processing fees are generally marketed under annual and multi-year agreements and are recognized ratably over the contracted terms beginning on the service start date for fixed fee arrangements and recognized as transactions are performed beginning on the service start date for per-transaction fee arrangements. Remote processing service fees are recognized monthly as the service is performed. Outsourcing service revenues are recognized as the service is performed.
	We also offer certain products on an application service provider basis, making our software functionality available on a remote hosting basis from our data centers. The data centers provide system and administrative support, as well as hosting services. Revenue on products sold on an application service provider basis is recognized on a monthly basis over the term of the contract beginning on the service start date of products hosted.
	This segment engages in multiple-element arrangements, which may contain any combination of software, hardware, implementation or consulting services, or maintenance services. For multiple element arrangements that do not include software, revenue is allocated to the separate elements based on their relative selling price and recognized in accordance with the revenue recognition criteria applicable to each element. Relative selling price is determined based on VSOE of selling price if available, TPE, if VSOE of selling price is not available, or ESP if neither VSOE of selling price nor TPE is available. For multiple-element arrangements accounted for in accordance with specific software accounting guidance when some elements are delivered prior to others in an arrangement and VSOE of fair value exists for the undelivered elements, revenue for the delivered elements is recognized upon delivery of such items. The segment establishes VSOE for hardware and implementation and consulting services based on the price charged when sold separately, and for maintenance services, based on renewal rates offered to customers. Revenue for the software element is recognized under the residual method only when fair value has been established for all of the undelivered elements in an arrangement. If fair value cannot be established for any undelivered element, all of the arrangement’s revenue is deferred until the delivery of the last element or until the fair value of the undelivered element is determinable. For multiple-element arrangements with both software elements and nonsoftware elements, arrangement consideration is allocated between the software elements as a whole and nonsoftware elements.  The segment then further allocates consideration to the individual elements within the software group, and revenue is recognized for all elements under the applicable accounting guidance and our policies described above.
	Supplier Incentives: Fees for service and other incentives received from suppliers, relating to the purchase or distribution of inventory, are generally reported as a reduction to cost of goods sold. We consider these fees and other incentives to represent product discounts and as a result, the amounts are recorded as a reduction of product cost and are recognized through cost of goods sold upon the sale of the related inventory.
	Supplier Reserves: We establish reserves against amounts due from suppliers relating to various price and rebate incentives, including deductions or billings taken against payments otherwise due to them. These reserve estimates are established based on judgment after considering the status of current outstanding claims, historical experience with the suppliers, the specific incentive programs and any other pertinent information available. We evaluate the amounts due from suppliers on a continual basis and adjust the reserve estimates when appropriate based on changes in factual circumstances. As of March 31, 2014 and 2013 supplier reserves were $181 million and $164 million. The ultimate outcome of any outstanding claims may be different than our estimate. All of the supplier reserves at March 31, 2014 and 2013 pertain to our Distribution Solutions segment.
	Income Taxes: We account for income taxes under the asset and liability method, which requires the recognition of deferred tax assets and liabilities for the expected future tax consequences of events that have been included in the financial statements. Under this method, deferred tax assets and liabilities are determined based on the difference between the financial statements and the tax basis of assets and liabilities using enacted tax rates in effect for the year in which the differences are expected to reverse. Tax benefits from uncertain tax positions are recognized when it is more likely than not that the position will be sustained upon examination, including resolutions of any related appeals or litigation processes, based on the technical merits. The amount recognized is measured as the largest amount of tax benefit that is greater than 50 percent likely of being realized upon effective settlements. Deferred taxes are not provided on undistributed earnings of our foreign operations that are considered to be permanently reinvested.
	Foreign Currency Translation: Our international subsidiaries generally consider their local currency to be their functional currency. Assets and liabilities of these international subsidiaries are translated into U.S. dollars at year-end exchange rates and revenues and expenses are translated at average exchange rates during the year. Currency translation adjustments for the year are included in other comprehensive income or loss in the statements of consolidated comprehensive income, and the cumulative effect is included in the stockholders’ equity section of the consolidated balance sheets. When we sell all or substantially all of an international entity, the related share of the cumulative currency translation adjustment is removed from stockholders’ equity and is included in the gain or loss on sale in the consolidated statements of operations. Realized gains and losses from currency exchange transactions are recorded in operating expenses in the consolidated statements of operations and were not material to our consolidated results of operations in 2014, 2013 or 2012.
	Derivative Financial Instruments: Derivative financial instruments are used principally in the management of foreign currency and interest rate exposures and are recorded on the consolidated balance sheets at fair value. If a derivative is designated as a fair value hedge, the changes in the fair value of the derivative and of the hedged item attributable to the hedged risk are recognized as a charge or credit to earnings. If the derivative is designated as a cash flow hedge, the effective portions of changes in the fair value of the derivative are included in other comprehensive income or loss in the statements of consolidated comprehensive income, and the cumulative effect is included in the stockholders’ equity section of the consolidated balance sheets. The cumulative changes in fair value are reclassed to the consolidated statements of operations when the hedged item affects earnings. We periodically evaluate hedge effectiveness, and ineffective portions of changes in the fair value of cash flow hedges are recognized as a charge or credit to earnings. Derivative instruments not designated as hedges are marked-to-market at the end of each accounting period with the change included in earnings.
	Comprehensive Income: Comprehensive income consists of two components, net income and other comprehensive income. Other comprehensive income refers to revenue, expenses, and gains and losses that under GAAP are recorded as an element of shareholders’ equity but are excluded from net income. Our other comprehensive income consists of foreign currency translation adjustments from those subsidiaries where the local currency is the functional currency, unrealized gains and losses on cash flow hedges, as well as unrealized gains and losses on retirement-related benefit plans.
	Noncontrolling Interests: Noncontrolling interests primarily represent the portion of Celesio’s profit or loss, net assets and comprehensive income that is not allocable to McKesson Corporation.
	Share-Based Compensation: We account for all share-based compensation transactions using a fair-value based measurement method. The share-based compensation expense, for the portion of the awards that is ultimately expected to vest, is recognized on a straight-line basis over the requisite service period. The compensation expense recognized has been classified in the consolidated statements of operations or capitalized on the consolidated balance sheets in the same manner as cash compensation paid to our employees.
	Loss Contingencies: We are subject to various claims, other pending and potential legal actions for damages, investigations relating to governmental laws and regulations and other matters arising out of the normal conduct of our business. When a loss is considered probable and reasonably estimable, we record a liability in the amount of our best estimate for the ultimate loss. However, the likelihood of a loss with respect to a particular contingency is often difficult to predict and determining a meaningful estimate of the loss or a range of loss may not be practicable based on the information available and the potential effect of future events and decisions by third parties that will determine the ultimate resolution of the contingency. Moreover, it is not uncommon for such matters to be resolved over many years, during which time relevant developments and new information must be reevaluated at least quarterly to determine both the likelihood of potential loss and whether it is possible to reasonably estimate a range of possible loss. When a loss is probable but a reasonable estimate cannot be made, disclosure of the proceeding is provided.
	Disclosure also is provided when it is reasonably possible that a loss will be incurred or when it is reasonably possible that the amount of a loss will exceed the recorded provision. We review all contingencies at least quarterly to determine whether the likelihood of loss has changed and to assess whether a reasonable estimate of the loss or range of the loss can be made. As discussed above, development of a meaningful estimate of loss or a range of potential loss is complex when the outcome is directly dependent on negotiations with or decisions by third parties, such as regulatory agencies, the court system and other interested parties. Such factors bear directly on whether it is possible to reasonably estimate a range of potential loss and boundaries of high and low estimate.
	Business Combinations: We account for acquired businesses using the acquisition method of accounting, which requires that once control is obtained of a business, 100% of the assets acquired and liabilities assumed, including amounts attributed to noncontrolling interests, be recorded at the date of acquisition at their respective fair values. Any excess of the purchase price over the estimated fair values of the net assets acquired is recorded as goodwill. Acquisition-related expenses and related restructuring costs are expensed as incurred.
	Several valuation methods may be used to determine the fair value of assets acquired and liabilities assumed.  For intangible assets, we typically use the income method.  This method starts with a forecast of all of the expected future net cash flows for each asset.  These cash flows are then adjusted to present value by applying an appropriate discount rate that reflects the risk factors associated with the cash flow streams.  Some of the more significant estimates and assumptions inherent in the income method or other methods include the amount and timing of projected future cash flows, the discount rate selected to measure the risks inherent in the future cash flows and the assessment of the asset’s life cycle and the competitive trends impacting the asset, including consideration of any technical, legal, regulatory, or economic barriers to entry.  Determining the useful life of an intangible asset also requires judgment as different types of intangible assets will have different useful lives and certain assets may even be considered to have indefinite useful lives.
	Recently Adopted Accounting Pronouncements
	Comprehensive Income: In the first quarter of 2014, we adopted disclosure guidance related to the reporting of amounts reclassified out of Accumulated Other Comprehensive Income (“AOCI”). The guidance requires disclosure of amounts reclassified out of AOCI by component. In addition, an entity is required to present either on the face of the statement of operations or in the notes, significant amounts reclassified out of AOCI by the respective line items of net income but only if the amount reclassified is required to be reclassified to net income in its entirety in the same reporting period. For amounts not reclassified in their entirety to net income, an entity is required to cross-reference to other disclosures that provide additional detail about those amounts. This guidance did not have a material effect on our consolidated financial statements.
	Balance Sheet Offsetting: In the first quarter of 2014, we adopted disclosure guidance related to the offsetting of assets and liabilities. The guidance requires an entity to disclose information about offsetting assets and liabilities for derivatives, repurchase agreements and reverse purchase agreements, and securities borrowing and securities lending transactions that are either offset in accordance with specific GAAP criteria or subject to a master netting arrangement or similar agreement. The amended guidance did not have a material effect on our consolidated financial statements.
	Recently Issued Accounting Pronouncements Not Yet Adopted
	Cumulative Translation Adjustments: In March 2013, amended guidance was issued for parent’s accounting for the cumulative translation adjustment upon derecognition of certain subsidiaries or group of assets within a foreign entity or of an investment in a foreign entity.  The amended guidance requires the release of any cumulative translation adjustment into net income only upon complete or substantially complete liquidation of a controlling interest in a subsidiary or a group of assets within a foreign entity.  Also, it requires the release of all or a pro rata portion of the cumulative translation adjustment to net income in case of sale of an equity method investment that is a foreign entity.  The amended guidance is applicable to us effective first quarter of fiscal 2015. Early adoption is permitted.  We are currently evaluating the impact of this amended guidance on our consolidated financial statements.
	Discontinued Operations: In April 2014, amended guidance was issued for reporting of discontinued operations and disclosures of disposals of components.  The amended guidance raises the threshold for disposals to qualify as discontinued operations and permits significant continuing involvement and continuing cash flows with the discontinued operation.  In addition, the amended guidance requires additional disclosures for discontinued operations and new disclosures for individually material disposal transactions that do not meet the definition of a discontinued operation.  The amended guidance is effective for us prospectively commencing in the first quarter of 2016.  Early adoption is permitted. We are currently evaluating the impact of this amended guidance on our consolidated financial statements.

Business_Combinations

Business Combinations	12 Months Ended
	Mar. 31, 2014
Business Combinations [Abstract]	'
Business Combinations	'
	Business Combinations
	Fiscal 2014
	On February 6, 2014, we completed the acquisition of 77.6% of the then outstanding common shares of Celesio AG (“Celesio”) and certain convertible bonds of Celesio for cash consideration of $4.5 billion, net of cash acquired (the “Acquisition”). Upon the acquisition, our ownership of Celesio’s fully diluted common shares was 75.6% and, as required, we consolidated Celesio’s debt with a fair value of $2.3 billion as a liability on our consolidated balance sheet. The Acquisition was funded by utilizing a senior bridge loan, our existing accounts receivable sales facility and cash on hand. Celesio is an international wholesale and retail company and a provider of logistics and services to the pharmaceutical and healthcare sectors. Celesio’s headquarters is in Stuttgart, Germany and it operates in 14 countries around the world. The acquisition of Celesio expands our global geographic area; the combined company will be one of the largest pharmaceutical wholesalers and providers of logistics and services in the healthcare sector worldwide.
	Our acquisition of Celesio was consummated through a series of transactions:
	•	129.3 million of common shares of Celesio were acquired from Franz Haniel & Cie. GmbH (“Haniel”) for cash consideration of €23.50 per common share or $4,128 million.
	•	4,840 of the 7,000 convertible bonds issued by Celesio in the nominal aggregate amount of €350 million due in October 2014 (the “2014 Bonds”), and 2,180 of the 3,500 convertible bonds issued by Celesio in the nominal amount of €350 million due in April 2018 (the “2018 Bonds”) were acquired from Elliot International, L.P., The Liverpool Limited Partnership and Elliot Capital Advisers, L.P. (together, the “Elliot Group”) for cash consideration of $951 million. The 2,180 acquired 2018 Bonds were converted to 11.4 million common shares of Celesio.
	•	303 of the 2014 Bonds and 216 of the 2018 Bonds were acquired in private transactions for cash consideration of $63 million. 139 of the acquired 2018 Bonds were converted to 0.7 million common shares of Celesio.
	From February 7, 2014 through March 31, 2014, we converted our remaining 2014 Bonds and 2018 Bonds into 11.9 million of Celesio common shares.  Also during this time period, substantially all of the remaining 2014 Bonds and 2018 Bonds held by third parties were converted to 9 million of Celesio common shares valued at $313 million and approximately $30 million in cash.  At March 31, 2014, we owned approximately 75.4% of Celesio’s outstanding and fully diluted common shares.
	In accordance with a business combination agreement that we entered into with Celesio in January 2014, on February 28, 2014 and April 7, 2014 we launched voluntary public tender offers for the common shares of Celesio that remain outstanding for €23.50 per share. In April 2014, the last of these tender offers expired and we acquired 1 million of additional common shares. We also intend to enter into a domination and profit and loss transfer agreement, with Celesio as the dominated party, pursuant to Sections 291 et seq. of the German Stock Corporation Act (Aktiengesetz - AktG). Such a domination and profit and loss transfer agreement does not require any further regulatory approval.
	The following table summarizes the preliminary recording of the fair values of the assets acquired and liabilities assumed as of the acquisition date. Due to the recent timing of the acquisition, these amounts are subject to change within the measurement period as our fair value assessments are finalized.
	(In millions)	Amounts
		Recognized as of
		Acquisition Date
		(Provisional)
	Receivables	$	3,425
	Other current assets, net of cash and cash equivalents acquired	2,413
	Goodwill	3,570
	Intangible assets	3,018
	Other long-term assets	1,272
	Current liabilities	(4,096		)
	Short-term borrowings and current portion of long-term debt	(1,990		)
	Long-term debt	(322		)
	Other long-term liabilities	(1,293		)
	Fair value of net assets, less cash and cash equivalents	5,997
	Less: Noncontrolling Interests	(1,500		)
	Net assets acquired, net of cash and cash equivalents	$	4,497
	Included in the purchase price allocation are acquired identifiable intangibles of $3,018 million, the fair value of which was primarily determined by applying the income approach, using several significant unobservable inputs for projected cash flows and a discount rate. These inputs are considered Level 3 inputs under the fair value measurements and disclosure guidance. Acquired intangibles primarily consist of $1,574 million of customer relationships, $1,202 million of pharmacy licenses and $172 million of trademarks. The estimated weighted average life of the customer relationships, pharmacy licenses, trademarks and total intangible assets are eleven years, twenty-six years, fourteen years and seventeen years.
	The fair value of Celesio’s long-term debt was determined by quoted market prices in a less active market and other observable inputs from available market information, which are considered to be Level 2 inputs under the fair value measurements and disclosure guidance. The fair values of the conversion options on Celesio’s convertible bonds, which are classified as current liabilities, were determined by using an option pricing model that uses observable market data for all inputs, such as historical volatility of the Company’s common stock, risk-free interest rate and other factors that are considered to be Level 2 inputs under the fair value measurements and disclosure guidance.
	The fair value of the noncontrolling interests on the date of acquisition of $1,500 million was made up of the following components:
	(In millions)	Amounts
		Recognized as of
		Acquisition Date
		(Provisional)
	Fair value of Celesio common shares not acquired by McKesson	$	1,412
	Fair value of Celesio’s previously existing noncontrolling interests	88
	Total	$	1,500
	The fair value of the noncontrolling interests for the Celesio common shares that were not acquired by McKesson was determined by a quoted market price that is considered to be a Level 1 input under the fair value measurements and disclosure guidance.
	The excess of the purchase price and the noncontrolling interests over the fair value of the acquired net assets has been allocated to goodwill, which primarily reflects the expected future benefits to be realized upon integrating the business. Most of the goodwill is not expected to be deductible for tax purposes.
	Financial results for Celesio since the acquisition date are included in the results of operations for the fourth quarter and year ended March 31, 2014 within our International pharmaceutical distribution and services business, which is part of our Distribution Solutions segment. Celesio contributed $4.8 billion of revenues and immaterial net earnings from the date of the acquisition through March 31, 2014.
	The following table provides pro forma results of operations for the years ended March 31, 2014 and March 31, 2013, as if Celesio had been acquired as of April 1, 2012. The pro forma results include the effect of preliminary purchase accounting adjustments such as the estimated changes in depreciation and amortization expense on the acquired tangible and intangible assets, financing costs, and related income tax expense. These adjustments are subject to change within the measurement period as our fair values assessments are finalized. The pro forma results do not reflect any material cost of integration activities or benefits that may result from synergies that may be derived from any integration activities. Accordingly, such amounts are not necessarily indicative of the results if the acquisition had occurred on the date indicated or which may occur in the future.
		Unaudited pro forma for the
		Years Ended March 31,
	(In millions)	2014			2013
	Net revenues	$	161,483		$	150,395
	Net income from continuing operations attributable to McKesson (1)	$	1,493		$	1,202
	-1	Includes $89 million of after-tax acquisition-related expenses and a $28 million after-tax charge associated with our portion of the reversal of a step-up to fair value of Celesio’s inventory at the date of acquisition.  These expenses were incurred in 2014; for pro forma purposes, they are allocated to 2013.
	Refer to Financial Note 14, “Debt and Financing Activities,” for additional information on the assumption and extinguishment of acquired debt and long-term debt issued to fund a portion of this acquisition.
	Fiscal 2013
	On February 22, 2013, we acquired all of the outstanding shares of PSS World Medical, Inc. (“PSS World Medical”) of Jacksonville, Florida for $29.00 per share plus the assumption of PSS World Medical’s debt, or approximately $1.9 billion in aggregate, consisting of cash consideration of $1.3 billion, net of cash acquired, and the assumption of long-term debt with a fair value of $0.6 billion. The cash paid at acquisition was funded from cash on hand and the issuance of long-term debt. PSS World Medical markets and distributes medical products and services throughout the United States. The acquisition of PSS World Medical expands our existing Medical-Surgical business.
	Included in the purchase price allocation are acquired identifiable intangibles of $568 million, the fair value of which was primarily determined by applying the income approach, using several significant unobservable inputs for projected cash flows and a discount rate. These inputs are considered Level 3 inputs under the fair value measurements and disclosure guidance. Acquired intangibles primarily consist of $539 million of customer lists and $15 million of trademarks and trade names. The estimated weighted average lives of the customer lists, trademarks and trade names and total intangible assets are nine years, two years and nine years. The fair values of the debt acquired was determined using quoted market prices and other inputs that were derived from available market information, which are considered to be Level 2 inputs under the fair value measurements and disclosure guidance. Refer to Financial Note 14, “Debt and Financing Activities,” for additional information on the assumption and redemption of acquired debt and long-term debt issued to fund a portion of this acquisition. The excess of the purchase price over the net tangible and intangible assets of approximately $1,149 million was recorded as goodwill, which primarily reflects the expected future benefits to be realized upon integrating the business. Most of the goodwill is not expected to be deductible for tax purposes.
	Financial results for PSS World Medical since the acquisition date are included in the results of operations within our Medical-Surgical distributions and services business, which is part of our Distribution Solutions segment beginning in the fourth quarter of 2013.
	On April 6, 2012, we purchased the remaining 50% ownership interest in our corporate headquarters building located in San Francisco, California, for $90 million, which was funded from cash on hand.  We previously held a 50% ownership interest and were the primary tenant in this building.  This transaction was accounted for as a step acquisition, which required that we re-measure our previously held 50% ownership interest to fair value and record the difference between the fair value and carrying value as a gain in the consolidated statements of operations.  The re-measurement to fair value resulted in a non-cash pre-tax gain of $81 million ($51 million after-tax), which was recorded as a gain on business combination within Corporate in the consolidated statements of operations during the first quarter of 2013.
	The total fair value of the net assets acquired was $180 million, which was allocated as follows: building and improvements of $113 million and land of $58 million with the remainder allocated for settlement of our pre-existing lease and lease intangible assets. The fair value of the building and improvements was determined based on current market replacement costs less depreciation and unamortized tenant improvement costs, as well as, other relevant market information, which are considered to be Level 3 inputs under the fair value measurements and disclosure guidance. The building and improvements have a weighted average useful life of 30 years. The fair value of the land was determined using comparable sales of land within the surrounding market, which is considered to be a Level 2 input.
	Fiscal 2012
	On March 25, 2012, we acquired substantially all of the assets of Drug Trading Company Limited, the independent banner business of the Katz Group Canada Inc. (“Katz Group”), and Medicine Shoppe Canada Inc., the franchise business of the Katz Group (collectively, “Katz Assets”) for $925 million, which was funded from cash on hand. The acquisition of the assets from the Drug Trading Company Limited consists of a marketing and purchasing arm of independently owned pharmacies in Canada. The acquisition of Medicine Shoppe Canada Inc. consists of the franchise business of providing services to independent pharmacies in Canada. Financial results for the acquired Katz Assets have been included in the results of operations within our Canadian pharmaceutical distribution and services business, which is part of our Distribution Solutions segment, beginning in the first quarter of 2013.
	Included in the purchase price allocation are acquired identifiable intangibles of $442 million, the fair value of which was determined by applying the income approach, using several unobservable inputs for projected cash flows and a discount rate. These inputs are considered Level 3 inputs under the fair value measurement and disclosure guidance. Acquired intangibles primarily consist of $318 million of service agreements and $114 million of trademarks and trade names. Service agreements, trademarks and trade names and total acquired intangibles assets each has an estimated weighted average life of 20 years. The excess of the purchase price over the net tangible and intangible assets of approximately $512 million was recorded as goodwill, which primarily reflects the expected future benefits to be realized upon integrating the business. The amount of goodwill expected to be deductible for tax purposes is $290 million.
	During the last three years, we also completed a number of other smaller acquisitions within both of our operating segments. Financial results for our business acquisitions have been included in our consolidated financial statements since their respective acquisition dates. Purchase prices for our business acquisitions have been allocated based on estimated fair values at the date of acquisition.
	We incurred the following acquisition expenses and related adjustments:
		Years Ended March 31,
	(In millions)	2014			2013			2012
	Cost of Sales	$	3		$	—		$	—
	Operating Expenses
	Transaction closing expenses	39			16			3
Restructuring, severance and relocation	43			30			3
Other integration related expenses	73			25			20
Gain on business combination	—			(81		)	—
Total	155			(10		)	26
Other Income, Net	14			—			—
Interest Expense - bridge loan fees	46			11			—
Total Acquisition Expenses and Related Adjustments	$	218		$	1		$	26
The acquisition expenses and related adjustments by segment is as follows:
	Years Ended March 31,
(In millions)	2014			2013			2012
Cost of Sales - Technology Solutions	$	3		$	—		$	—
Operating Expenses
Distribution Solutions	119			47			24
Technology Solutions	15			7			1
Corporate	21			(64		)	1
Total	155			(10		)	26
Corporate - Other Income, Net	14			—			—
Corporate - Interest Expense	46			11			—
Total Acquisition Expenses and Related Adjustments	$	218		$	1		$	26
Acquisition expenses and related adjustments incurred in 2014 were primarily related to our acquisition of Celesio and the integration of PSS World Medical. Related expenses for 2013 primarily pertained to our acquisition of PSS World Medical and our gain on business combination from our acquisition of the remaining 50% ownership interest in our corporate headquarters building, and for 2012 were primarily incurred to integrate a 2011 acquisition. Additional acquisition-related expenses are expected to be incurred as we integrate our acquired businesses.
Goodwill recognized for our business acquisitions is generally not expected to be deductible for tax purposes. However, if we acquire the assets of a company, the goodwill may be deductible for tax purposes. For all acquisitions other than Celesio, the pro forma results of operations for our business acquisitions, and the results of operations for these acquisitions since the acquisition date have not been presented because the effects were not material to the consolidated financial statements on either an individual or an aggregate basis.

Discontinued_Operations

Discontinued Operations	12 Months Ended
	Mar. 31, 2014
Discontinued Operations and Disposal Groups [Abstract]	'
Discontinued Operation	'
	Discontinued Operations
	In 2014, we committed to a plan to sell our International Technology and our Hospital Automation businesses from our Technology Solutions segment and certain businesses from our Distribution Solutions segment. The results of operations and cash flows for these businesses are classified as discontinued operations for the years ended March 31, 2014, 2013 and 2012 in our consolidated financial statements.
	During the third quarter of 2014, we recorded an $80 million pre-tax ($80 million after-tax) non-cash impairment charge to reduce the carrying value of our International Technology business to its estimated net realizable value (fair value less costs to sell). The charge was primarily the result of the terms of the preliminary purchase offers received for this business during the third quarter of 2014. The impairment charge was primarily attributed to goodwill and other long-lived assets and as a result, there was no tax benefit associated with this charge. The ultimate selling price of our International Technology business may be higher or lower than our current assessment of fair value.
	During the third quarter of 2014, we sold our Hospital Automation business for net cash proceeds of $55 million and recorded a pre-tax and after-tax loss of $5 million and $7 million.
	A summary of results of discontinued operations is as follows:
		Years Ended March 31,
	(In millions)	2014			2013			2012
	Revenues	$	421		$	386		$	413
	Income (loss) from discontinued operations	$	(102	)	$	(9	)	$	26
	Loss on sale	(5		)	—			—
	Income (loss) from discontinued operations before income tax	(107		)	(9		)	26
	Income tax (expense) benefit	11			—			(2		)
	Income (loss) from discontinued operations, net of tax	$	(96	)	$	(9	)	$	24
	The assets and liabilities of our discontinued operations were classified as held-for-sale effective June 30, 2013. All applicable assets of the businesses to be sold are included under the caption “Prepaid expenses and other” and all applicable liabilities under the caption “Other accrued liabilities” within our consolidated balance sheet at March 31, 2014. The carrying values of the assets and liabilities classified as held-for-sale were $267 million and $248 million at March 31, 2014.

Asset_Impairments_and_Product_

Asset Impairments and Product Alignment Charges	12 Months Ended
	Mar. 31, 2014
Asset Impairment Charges [Abstract]	'
Asset Impairments and Product Alignment Charges	'
	Asset Impairments and Product Alignment Charges
	In 2014, 2013 and 2012, we recorded asset impairments and product alignment charges of $57 million, $46 million and $51 million in our Technology Solutions segment.
	Fiscal 2014
	During the third quarter of 2014, our Technology Solutions segment recorded pre-tax charges totaling $57 million. These charges primarily consist of $35 million of product alignment charges, $15 million of integration-related expenses and $7 million of reduction-in-workforce severance charges. Included in the total charge was $35 million for severance for employees primarily in our research and development, customer services and sales functions, and $15 million for asset impairments which primarily represents the write-off of deferred costs related to a product that will no longer be developed. Charges were recorded in our consolidated statement of operations as follows: $34 million in cost of sales and $23 million in operating expenses.
	Fiscal 2013
	During the fourth quarter of 2013, we recorded $46 million of non-cash pre-tax impairment charges. These charges were the result of a significant decrease in estimated revenues for a software product. The charge included a $36 million goodwill impairment to reduce the carrying value of goodwill within the applicable reporting unit to its implied fair value. In addition, the goodwill had a nominal tax basis. This impairment charge was recorded in operating expenses within our consolidated statement of operations. Refer to Financial Note 19, “Fair Value Measurements,” for more information on this nonrecurring fair value measurement. The balance of the charge represents a $10 million impairment to reduce the carrying value of the unamortized capitalized software held for sale costs for this product to its net realizable value. We concluded that the estimated future undiscounted revenues, net of estimated related costs, were insufficient to recover its carrying value. This impairment charge was recorded in cost of sales within our consolidated statement of operations.
	Fiscal 2012
	During the third quarter of 2012, we approved a plan to align our hospital clinical and revenue cycle healthcare software products within our Technology Solutions segment. As part of this alignment strategy, we began converging our core clinical and revenue cycle Horizon and Paragon product lines onto Paragon’s Microsoft®-based platform. Additionally, we stopped development of our Horizon Enterprise Revenue Management™ (“HzERM”) software product. The plan resulted in a pre-tax charge of $51 million in 2012, of which $31 million was recorded to cost of sales and $20 million was recorded to operating expenses within our consolidated statement of operations. The majority of these charges were incurred in the third quarter of 2012. The pre-tax charge included $24 million of non-cash asset impairment charges, primarily for the write-off of prepaid licenses and commissions and capitalized internal use software that were determined to be obsolete as they would not be utilized going forward, $10 million for severance, $7 million for customer allowances and $10 million for other charges.

Impairment_and_Sale_of_an_Equi

Impairment and Sale of an Equity Investment	12 Months Ended
	Mar. 31, 2014
Equity Method Investment and Joint Venture Disclosure [Abstract]	'
Equity Method Investments and Joint Ventures Disclosure [Text Block]	'
	Impairment and Sale of an Equity Investment
	During 2013, we committed to a plan to sell our 49% equity interest in Nadro, S.A. de C.V. (“Nadro”) and in the fourth quarter of 2013 recorded a pre-tax impairment charge of $191 million reducing the investment’s carrying value to its estimated fair value. The charge reflected deterioration in Nadro’s market position, projected lower revenue growth rates and operating margins and continued business challenges in the wholesale pharmaceutical distribution business in Mexico. Cumulative foreign currency translation losses of $69 million were included in the assessment of the investment’s carrying value for purposes of calculating the impairment charge. Cumulative foreign currency translation losses (net of tax), were included in Accumulated Other Comprehensive Income on our consolidated balance sheet at March 31, 2013. The impairment charge was recorded in impairment of an equity investment in the consolidated statements of operations within our Distribution Solutions segment. Refer to Financial Note 19, “Fair Value Measurements,” for more information on this fair value measurement.
	In September 2013, we completed the sale of our 49% equity interest in Nadro which resulted in no material gain or loss. Under the terms of the agreement, we received $41 million in total cash consideration. There was no material gain or loss on the disposition based on the adjusted net realizable value of the investment at the time of the sale. Prior to the sale, our investment in Nadro was accounted for under the equity method of accounting within our Distribution Solutions segment.

ShareBased_Compensation

Share-Based Compensation	12 Months Ended
	Mar. 31, 2014
Share-based Compensation [Abstract]	'
Share-Based Compensation	'
	Share-Based Compensation
	We provide share-based compensation to our employees, officers and non-employee directors, including stock options, an employee stock purchase plan, restricted stock units (“RSUs”) and performance-based restricted stock units (“PeRSUs”) (collectively, “share-based awards”). Most of our share-based awards are granted in the first quarter of each fiscal year.
	Compensation expense for the share-based awards is recognized for the portion of awards ultimately expected to vest. We estimate the number of share-based awards, which will ultimately vest primarily based on historical experience. The estimated forfeiture rate established upon grant is re-assessed throughout the requisite service period and is adjusted when actual forfeitures occur. The actual forfeitures in future reporting periods could be higher or lower than current estimates.
	The compensation expense recognized has been classified in the consolidated statements of operations or capitalized in the consolidated balance sheets in the same manner as cash compensation paid to our employees. There was no material share-based compensation expense capitalized as part of the cost of an asset in 2014, 2013 and 2012.
	Impact on Net Income
	The components of share-based compensation expense and related tax benefits are as follows:
		Years Ended March 31,
	(In millions)	2014				2013				2012
	RSUs (1)	$	88			$	109			$	97
	PeRSUs (2)	38				23				24
	Stock options	22				24				23
	Employee stock purchase plan	12				11				10
	Share-based compensation expense	160				167				154
	Tax benefit for share-based compensation expense (3)	(55		)		(59		)		(55		)
	Share-based compensation expense, net of tax	$	105			$	108			$	99
	-1	This expense was primarily the result of PeRSUs awarded in prior years, which converted to RSUs due to the attainment of goals during the applicable years’ performance period.
	-2	Represents estimated compensation expense for PeRSUs that are conditional upon attaining performance objectives during the current year’s performance period.
	-3	Income tax benefit is computed using the tax rates of applicable tax jurisdictions. Additionally, a portion of pre-tax compensation expense is not tax-deductible.
	Stock Plans
	In July 2013, our stockholders approved the 2013 Stock Plan to replace the 2005 Stock Plan. These stock plans provide our employees, officers and non-employee directors the opportunity to receive equity-based, long-term incentives in the form of stock options, restricted stock, RSUs, PeRSUs and other share-based awards. The 2013 Stock Plan reserves 30.0 million shares plus the remaining number of shares reserved but unused under the 2005 Stock Plan. As of March 31, 2014, 33.6 million shares remain available for future grant under the 2013 Stock Plan.
	Stock Options
	Stock options are granted at no less than fair market value, and those options granted under the 2013 Stock Plan generally have a contractual term of seven years and follow a four-year vesting schedule.
	Compensation expense for stock options is recognized on a straight-line basis over the requisite service period and is based on the grant-date fair value for the portion of the awards that is ultimately expected to vest. We use the Black-Scholes options-pricing model to estimate the fair value of our stock options. Once the fair value of an employee stock option is determined, current accounting practices do not permit it to be changed, even if the estimates used are different from actual. The options-pricing model requires the use of various estimates and assumptions as follows:
	•	Expected stock price volatility is based on a combination of historical volatility of our common stock and implied market volatility. We believe that this market-based input provides a reasonable estimate of our future stock price movements and is consistent with employee stock option valuation considerations.
	•	Expected dividend yield is based on historical experience and investors’ current expectations.
	•	The risk-free interest rate for periods within the expected life of the option is based on the constant maturity U.S. Treasury rate in effect at the time of grant.
	•	Expected life of the options is based primarily on historical employee stock option exercises and other behavior data and reflects the impact of changes in contractual life of current option grants compared to our historical grants.
	Weighted-average assumptions used to estimate the fair value of employee stock options were as follows:
		Years Ended March 31,
		2014		2013		2012
	Expected stock price volatility	22%		27%		27%
	Expected dividend yield	0.70%		0.90%		1.00%
	Risk-free interest rate	0.70%		0.80%		2.10%
	Expected life (in years)	4		5		5
	The following is a summary of stock options outstanding at March 31, 2014:
									Options Outstanding						Options Exercisable
	Range of Exercise								Number of		Weighted-		Weighted-		Number of	Weighted-
	Prices								Options		Average		Average		Options	Average
									Outstanding		Remaining		Exercise Price		Exercisable at	Exercise Price
									at Year End		Contractual				Year End
									(In millions)		Life (Years)				(In millions)
	$	35.53		–	$	69			3		2		$	55.7	2	$	53.76
	69.01			–	169.44				3		5		96.35		1	84.81
									6						3
	The following table summarizes stock option activity during 2014:
	(In millions, except per share data)	Shares		Weighted-				Weighted-		Aggregate
				Average				Average		Intrinsic
				Exercise				Remaining		Value (2)
				Price				Contractual
								Term (Years)
	Outstanding, March 31, 2013	7		$	65.79			4		$	260
	Granted	1		120.79
	Exercised	-2		56.74
	Outstanding, March 31, 2014	6		$	78.07			4		$	473
	Vested and expected to vest (1)	5		$	77.27			4		$	472
	Vested and exercisable, March 31, 2014	3		61.07				3		281
	-1	The number of options expected to vest takes into account an estimate of expected forfeitures.
	-2	The intrinsic value is calculated as the difference between the period-end market price of the Company’s common stock and the exercise price of “in-the-money” options.
	The following table provides data related to stock option activity:
		Years Ended March 31,
	(In millions, except per share data)	2014				2013				2012
	Weighted-average grant date fair value per stock option	$	21.45			$	19.63			$	20.32
	Aggregate intrinsic value on exercise	$	144			$	107			$	108
Cash received upon exercise	$	111			$	106			$	113
Tax benefits realized related to exercise	$	55			$	41			$	40
Total fair value of stock options vested	$	24			$	24			$	23
Total compensation cost, net of estimated forfeitures, related to unvested stock options not yet recognized, pre-tax	$	29			$	37			$	40
Weighted-average period in years over which stock option compensation cost is expected to be recognized	1				1				1
RSUs and PeRSUs
RSUs, which entitle the holder to receive at the end of a vesting term a specified number of shares of the Company’s common stock, are accounted for at fair value at the date of grant. Total compensation expense for RSUs under our stock plans is determined by the product of the number of shares that are expected to vest and the grant date market price of the Company’s common stock. The Compensation Committee determines the vesting terms at the time of grant. These awards generally vest in three to four years. We recognize expense for RSUs on a straight-line basis over the requisite service period.
Non-employee directors receive an annual grant of RSUs, which vest immediately and are expensed upon grant. The director may choose to receive payment immediately or defer receipt of the underlying shares if they meet director stock ownership guidelines. At March 31, 2014, 150,000 RSUs for our directors are vested.
PeRSUs are RSUs for which the number of RSUs awarded may be conditional upon the attainment of one or more performance objectives over a specified period. PeRSUs are accounted for as variable awards until the performance goals are reached and the grant date is established. Total compensation expense for PeRSUs is determined by the product of the number of shares eligible to be awarded and expected to vest, and the market price of the Company’s common stock, commencing at the inception of the requisite service period. During the performance period, the compensation expense for PeRSUs is re-computed using the market price and the performance modifier at the end of a reporting period. At the end of the performance period, if the goals are attained, the awards are granted and classified as RSUs and accounted for on that basis. We recognize compensation expense of these awards on a straight-line basis over the requisite aggregate service period of generally four years.
The following table summarizes RSU activity during 2014:
(In millions, except per share data)	Shares		Weighted-
			Average
			Grant Date Fair
			Value Per Share
Nonvested, March 31, 2013	6		$	76.2
Granted	1		120.63
Vested	-3		67.32
Nonvested, March 31, 2014	4		$	93.25
The following table provides data related to RSU activity:
	Years Ended March 31,
(In millions)	2014				2013				2012
Total fair value of shares vested	$	184			$	66			$	44
Total compensation cost, net of estimated forfeitures, related to nonvested RSU awards not yet recognized, pre-tax	$	115			$	128			$	143
Weighted-average period in years over which RSU cost is expected to be recognized	2				2				3
In May 2013, the Compensation Committee approved 1 million PeRSU target share units representing the base number of awards that could be granted, if goals are attained, and would be granted in the first quarter of 2014 (the “2014 PeRSU”). These target share units are not included in the table above as they have not been granted in the form of RSUs. As of March 31, 2014, the total pre-tax compensation expense, net of estimated forfeitures, related to nonvested 2014 PeRSUs not yet recognized was approximately $121 million, (based on the period-end market price of the Company’s common stock) and the weighted-average period over which the cost is expected to be recognized is three years.
Employee Stock Purchase Plan (“ESPP”)
The Company has an ESPP under which 21 million shares have been authorized for issuance. The ESPP allows eligible employees to purchase shares of our common stock through payroll deductions. The deductions occur over three-month purchase periods and the shares are then purchased at 85% of the market price at the end of each purchase period. Employees are allowed to terminate their participation in the ESPP at any time during the purchase period prior to the purchase of the shares. The 15% discount provided to employees on these shares is included in compensation expense. The shares related to funds outstanding at the end of a quarter are included in the calculation of diluted weighted average shares outstanding. These amounts have not been significant. Shares issued under the ESPP in 2014, 2013 and 2012 were nil, 1 million and 1 million. At March 31, 2014, 5 million shares remain available for issuance.

Other_Income_Expense_Net

Other Income (Expense), Net	12 Months Ended
	Mar. 31, 2014
Other Nonoperating Income (Expense) [Abstract]	'
Other Income (Expense), Net	'
	Other Income, Net
		Years Ended March 31,
	(In millions)	2014			2013		2012
	Interest income	$	23		$	22	$	19
	Equity in earnings (loss), net (1)	(3		)	3		9
	Other, net	12			9		(8		)
	Total	$	32		$	34	$	20
	-1	Primarily recorded within our Distribution Solutions segment.

Income_Taxes

Income Taxes	12 Months Ended
	Mar. 31, 2014
Income Tax Disclosure [Abstract]	'
Income Taxes	'
	Income Taxes
		Years Ended March 31,
	(In millions)	2014			2013			2012
	Income from continuing operations before income taxes
	U.S.	$	1,554		$	1,562		$	1,293
	Foreign	542			366			600
	Total income from continuing operations before income taxes	$	2,096		$	1,928		$	1,893
	Income tax expense related to continuing operations consists of the following:
		Years Ended March 31,
	(In millions)	2014			2013			2012
	Current
	Federal	$	484		$	(84	)	$	265
	State	64			14			51
	Foreign	178			40			28
	Total current	726			(30		)	344
	Deferred
	Federal	24			538			132
	State	10			80			29
	Foreign	(18		)	(7		)	9
	Total deferred	16			611			170
	Income tax expense	$	742		$	581		$	514
	Income tax expense included $94 million of net discrete tax expense in 2014, and $29 million and $66 million of net discrete tax benefit in 2013 and 2012. Discrete tax expense for 2014 primarily related to a $122 million charge regarding an unfavorable decision from the Tax Court of Canada with respect to transfer pricing issues. Included in the 2012 discrete tax benefit is a $31 million credit to income tax expense as a result of the reversal of an unrecognized tax benefit relating to our AWP litigation. The 2013 federal and state current income tax expense reflects the utilization of alternative minimum tax credit carryforwards.
	We have received reassessments from the Canada Revenue Agency (“CRA”) for a total of $219 million related to a transfer pricing matter impacting years 2003 through 2009. We previously appealed the reassessment for 2003 to the Tax Court of Canada and have filed a notice of objection for 2004 through 2009. On December 13, 2013, the Tax Court of Canada dismissed our appeal of the reassessment with respect to 2003. On January 10, 2014, we filed a Notice of Appeal to the Federal Court of Appeal in response to the judgment of the Tax Court of Canada. As a result of the unfavorable Tax Court Decision relating to 2003, we recognized a discrete tax expense of $122 million in the third quarter of 2014, which includes tax and interest, for the years 2003 through 2013. The ultimate resolution of these issues could result in an increase or decrease to income tax expense.
	We have received tax assessments of $98 million from the U.S. Internal Revenue Service (“IRS”) relating to 2003 through 2006. We are pursuing administrative relief through the appeals process. We continue to believe in the merits of our tax positions and that we have adequately provided for any potential adverse results relating to these examinations in our financial statements.
	The IRS is currently examining our U.S. corporation income tax returns for 2007 through 2009. The CRA is currently examining our Canadian income tax returns for 2010 through 2013. In nearly all jurisdictions, the tax years prior to 2003 are no longer subject to examination.
	Significant judgments and estimates are required in determining the consolidated income tax provision and evaluating income tax uncertainties. Although our major taxing jurisdictions are the U.S. and Canada, we are subject to income taxes in numerous foreign jurisdictions. Our income tax expense, deferred tax assets and liabilities and uncertain tax liabilities reflect management’s best assessment of estimated current and future taxes to be paid. We believe that we have made adequate provision for all income tax uncertainties.
	The reconciliation between our effective tax rate on income from continuing operations and statutory tax rate is as follows:
		Years Ended March 31,
	(In millions)	2014			2013			2012
	Income tax expense at federal statutory rate	$	734		$	670		$	670
	State income taxes net of federal tax benefit	57			58			56
	Foreign income taxed at various rates	(166		)	(136		)	(174		)
	Canadian litigation	122			—			—
	Unrecognized tax benefits and settlements	(6		)	1			(18		)
	Tax credits	(6		)	(13		)	(13		)
	Other, net	7			1			(7		)
	Income tax expense	$	742		$	581		$	514
	At March 31, 2014 undistributed earnings of our foreign operations totaling $4.2 billion were considered to be permanently reinvested. No deferred tax liability has been recognized on the basis difference created by such earnings since it is our intention to utilize those earnings in the foreign operations as well as to fund certain research and development activities for an indefinite period of time. The determination of the amount of deferred taxes on these earnings is not practicable because the computation would depend on a number of factors that cannot be known until a decision to repatriate the earnings is made.
	Deferred tax balances consisted of the following:
		March 31,
	(In millions)	2014			2013
	Assets
	Receivable allowances	$	106		$	84
	Deferred revenue	136			106
	Compensation and benefit related accruals	641			553
	Net operating loss and credit carryforwards	430			341
	Other	289			281
	Subtotal	1,602			1,365
	Less: valuation allowance	(270		)	(118		)
	Total assets	1,332			1,247
	Liabilities
	Inventory valuation and other assets	(2,163		)	(2,089		)
	Fixed assets and systems development costs	(321		)	(267		)
	Intangibles	(1,531		)	(734		)
	Other	(118		)	(24		)
	Total liabilities	(4,133		)	(3,114		)
	Net deferred tax liability	$	(2,801	)	$	(1,867	)
	Current net deferred tax asset	$	51		$	16
	Current net deferred tax liability	(1,588		)	(1,626		)
	Long-term deferred tax asset	19			21
	Long-term deferred tax liability	(1,283		)	(278		)
	Net deferred tax liability	$	(2,801	)	$	(1,867	)
	We assess the available positive and negative evidence to determine whether deferred tax assets are more likely than not to be realized.  As a result of this assessment, valuation allowances have been recorded on certain deferred tax assets in various tax jurisdictions.  The increase in valuation allowances in the current year relate primarily to net operating losses incurred in certain tax jurisdictions for which no tax benefit was recognized and deferred tax assets that were acquired as part of the Celesio acquisition which are not more likely than not to be realized.
We have federal, state and foreign net operating loss carryforwards of $53 million, $2,524 million and $935 million. The federal and state net operating losses will expire at various dates from 2015 through 2034. Substantially all of our foreign net operating losses have indefinite lives. In addition, we have Canadian research and development credit carryforwards of $11 million, and we believe it is more likely than not that these credits will be realized. The Canadian research and development credits will expire at various dates from 2029 to 2034.
The following table summarizes the activity related to our gross unrecognized tax benefits for the last three years:
	Years Ended March 31,
(In millions)	2014			2013			2012
Unrecognized tax benefits at beginning of period	$	560		$	595		$	635
Additions based on tax positions related to prior years	106			46			11
Reductions based on tax positions related to prior years	(31		)	(108		)	(72		)
Additions based on tax positions related to current year	23			31			37
Reductions based on settlements	(4		)	(2		)	(1		)
Reductions based on the lapse of the applicable statutes of limitations	(7		)	(2		)	(15		)
Unrecognized tax benefits at end of period	$	647		$	560		$	595
Of the total $647 million in unrecognized tax benefits at March 31, 2014, $490 million would reduce income tax expense and the effective tax rate if recognized. During the next twelve months, it is reasonably possible that audit resolutions and the expiration of statutes of limitations could potentially reduce our unrecognized tax benefits by up to $230 million. However, this amount may change because we continue to have ongoing negotiations with various taxing authorities throughout the year.
We report interest and penalties on unrecognized tax benefits as income tax expense. In 2014 and 2013, we recognized income tax expense of $48 million and a reduction to income tax expense of $8 million, related to interest and penalties in our consolidated statements of operations. The income tax expense for interest and penalties recognized in 2014 was primarily due to the additional interest resulting from the increase of our Canadian gross unrecognized tax benefits. The reduction to income tax expense in 2013 was primarily due to the reversal of accrued interest resulting from the reduction of our gross unrecognized tax benefits. At March 31, 2014 and 2013, we had $179 million and $131 million, accrued for the payment of interest and penalties on unrecognized tax benefits.

Earnings_Per_Common_Share

Earnings Per Common Share	12 Months Ended
	Mar. 31, 2014
Earnings Per Share [Abstract]	'
Earnings Per Common Share	'
	Earnings Per Common Share
	Basic earnings per common share attributable to McKesson are computed by dividing net income attributable to McKesson by the weighted average number of common shares outstanding during the reporting period. Diluted earnings per common share are computed similar to basic earnings per common share except that it reflects the potential dilution that could occur if dilutive securities or other obligations to issue common stock were exercised or converted into common stock.
	The computations for basic and diluted earnings per common share are as follows:
		Years Ended March 31,
	(In millions, except per share amounts)	2014			2013			2012
	Income from continuing operations	$	1,354		$	1,347		$	1,379
	Net loss attributable to noncontrolling interests	5			—			—
	Income from continuing operations attributable to McKesson	1,359			1,347			1,379
	Income (loss) from discontinued operations, net of tax	(96		)	(9		)	24
	Net income attributable to McKesson	$	1,263		$	1,338		$	1,403
	Weighted average common shares outstanding:
	Basic	229			235			246
	Effect of dilutive securities:
	Options to purchase common stock	1			1			2
	Restricted stock units	3			3			3
	Diluted	233			239			251
	Earnings (loss) per common share attributable to McKesson: (1)
	Diluted
	Continuing operations	$	5.83		$	5.62		$	5.49
	Discontinued operations	(0.42		)	(0.03		)	0.1
	Total	$	5.41		$	5.59		$	5.59
	Basic
	Continuing operations	$	5.93		$	5.74		$	5.6
	Discontinued operations	(0.42		)	(0.03		)	0.1
	Total	$	5.51		$	5.71		$	5.7
	-1	Certain computations may reflect rounding adjustments.
	Potentially dilutive securities primarily include outstanding stock options, RSUs and PeRSUs. Approximately 2 million, 2 million and 4 million of potentially dilutive securities were excluded from the computations of diluted net earnings per common share in 2014, 2013 and 2012, as they were anti-dilutive.

Receivables_Net

Receivables, Net	12 Months Ended
	Mar. 31, 2014
Receivables, Net, Current [Abstract]	'
Receivables, Net	'
	Receivables, Net
		March 31,
	(In millions)	2014			2013
	Customer accounts	$	12,543		$	8,683
	Other	1,780			1,423
	Total	14,323			10,106
	Allowances	(130		)	(131		)
	Net	$	14,193		$	9,975
	Other receivables primarily include amounts due from suppliers and customer unbilled receivables. The allowances are primarily for estimated uncollectible accounts.

Property_Plant_and_Equipment_N

Property, Plant and Equipment, Net	12 Months Ended
	Mar. 31, 2014
Property, Plant and Equipment, Net [Abstract]	'
Property, Plant and Equipment, Net	'
	Property, Plant and Equipment, Net
		March 31,
	(In millions)	2014			2013
	Land	$	221		$	129
	Building, machinery, equipment and other	3,180			2,400
	Total property, plant and equipment	3,401			2,529
	Accumulated depreciation	(1,179		)	(1,208		)
	Property, plant and equipment, net	$	2,222		$	1,321

Goodwill_and_Intangible_Assets

Goodwill and Intangible Assets, Net	12 Months Ended
	Mar. 31, 2014
Goodwill and Intangible Assets Disclosure [Abstract]	'
Goodwill and Intangible Assets, Net	'
	Goodwill and Intangible Assets, Net
	Changes in the carrying amount of goodwill were as follows:
	(In millions)	Distribution				Technology				Total
		Solutions				Solutions
	Balance, March 31, 2012	$	3,190			$	1,842			$	5,032
	Goodwill acquired	1,228				193				1,421
	Impairment	—				(36		)		(36		)
	Acquisition accounting and other adjustments	6				(1		)		5
	Foreign currency translation adjustments	(11		)		(6		)		(17		)
	Balance, March 31, 2013	$	4,413			$	1,992			$	6,405
	Goodwill acquired	3,649				—				3,649
	Amount reclassified to assets held-for-sale	(1		)		(127		)		(128		)
	Acquisition accounting, transfers and other adjustments	13				(12		)		1
	Foreign currency translation adjustments, net	4				(4		)		—
	Balance, March 31, 2014	$	8,078			$	1,849			$	9,927
	As of March 31, 2014 and 2013, the accumulated goodwill impairment losses were $36 million in our Technology Solutions segment.
	Information regarding intangible assets is as follows:
		March 31, 2014												March 31, 2013
	(Dollars in millions)	Weighted		Gross				Accumulated				Net		Gross		Accumulated			Net
		Average		Carrying				Amortization				Carrying		Carrying		Amortization			Carrying
		Remaining		Amount								Amount		Amount					Amount
		Amortization
		Period
		(Years)
	Customer lists	10		$	3,384			$	(863	)		$	2,521	$	1,761	$	(672	)	$	1,089
	Service agreements	16		995				(173		)		822		1,018		(114		)	904
	Pharmacy licenses	26		1,219				(11		)		1,208		—		—			—
	Trademarks and trade names	15		371				(59		)		312		208		(46		)	162
	Technology	3		219				(173		)		46		271		(207		)	64
	Other	5		165				(52		)		113		89		(38		)	51
	Total			$	6,353			$	(1,331	)		$	5,022	$	3,347	$	(1,077	)	$	2,270
	Amortization expense of intangible assets was $319 million, $215 million and $191 million for 2014, 2013 and 2012. Estimated annual amortization expense of intangible assets is as follows: $469 million, $509 million, $465 million, $461 million and $445 million for 2015 through 2019, and $2,673 million thereafter. All intangible assets were subject to amortization as of March 31, 2014 and 2013.

Capitalized_Software_Held_for_

Capitalized Software Held for Sale	12 Months Ended
	Mar. 31, 2014
Capitalized Computer Software, Net [Abstract]	'
Capitalized Software Held For Sale	'
	Capitalized Software Held for Sale, Net
	Changes in the carrying amount of capitalized software held for sale, net, which is included in other assets in the consolidated balance sheets, were as follows:
		Years Ended March 31,
	(In millions)	2014			2013			2012
	Balance, at beginning of period	$	126		$	144		$	152
	Amounts capitalized	40			49			47
	Amortization expense	(50		)	(56		)	(53		)
	Impairment charges	(12		)	(10		)	—
	Foreign currency translations adjustments, net	(1		)	(1		)	(2		)
	Balance, at end of period	$	103		$	126		$	144
	Additionally, third party royalty fees paid were $91 million, $88 million and $95 million during 2014, 2013 and 2012.

Debt_and_Financing_Activities

Debt and Financing Activities	12 Months Ended
	Mar. 31, 2014
Debt Disclosure [Abstract]	'
Debt and Financing Activities	'
	Debt and Financing Activities
	Information regarding long-term debt is as follows:
		March 31,
	(In millions)	2014			2013
	Denominated in U.S. Dollars
	6.50% Notes due February 15, 2014	$	—		$	350
	Floating Rate Notes due September 10, 2015	400			—
	0.95% Notes due December 4, 2015	499			499
	3.25% Notes due March 1, 2016	599			599
	5.70% Notes due March 1, 2017	500			500
	1.29% Notes due March 10, 2017	700			—
	1.40% Notes due March 15, 2018	499			499
	7.50% Notes due February 15, 2019	349			349
	2.28% Notes due March 15, 2019	1,100			—
	4.75% Notes due March 1, 2021	598			598
	2.70% Notes due December 15, 2022	400			400
	2.85% Notes due March 15, 2023	400			400
	3.80% Notes due March 15, 2024	1,100			—
	7.65% Debentures due March 1, 2027	175			175
	6.00% Notes due March 1, 2041	493			493
	4.88% Notes due March 15, 2044	800			—
	Other	27			11
	Denominated in Euro and other foreign currencies
	4.00% Bonds due October 18, 2016	507			—
	4.50% Bonds due April 26, 2017	737			—
	Promissory Notes	297			—
	Bank liabilities and other	193			—
	Total debt	10,373			4,873
	Less current portion	(1,424		)	(352		)
	Total long-term debt	$	8,949		$	4,521
	Senior Bridge Term Loan Facilities
	In connection with our acquisition of Celesio, in January 2014, we entered into a $5.5 billion 364‑day unsecured Senior Bridge Term Loan Agreement (the “2014 Bridge Loan”) under terms substantially similar to those in our existing revolving credit facility. On February 4, 2014, we borrowed $4,957 million under this facility, with such proceeds and cash on hand used to fund the acquisition of Celesio. On March 10, 2014, we repaid $4,076 million of the 2014 Bridge Loan borrowings with funds obtained from the issuance of long-term debt. On March 11, 2014, we repaid the remaining balance of the 2014 Bridge Loan borrowings using funds drawn on our Accounts Receivable Sales Facility and cash on hand. On April 30, 2014, the commitments under the 2014 Bridge Loan automatically terminated upon the settlement of the tender offers for the remaining common shares of Celesio. During the time it was outstanding, the 2014 Bridge Loan borrowings bore interest at 1.39% per annum, based on the London Interbank Offered Rate plus a margin based on the Company’s credit rating. Interest expense for 2014 included a total of $46 million of fees related to the 2014 Bridge Loan and a bridge loan agreement entered into during the third quarter of 2014 in anticipation of an earlier acquisition of Celesio.
	In connection with our acquisition of PSS World Medical, in December 2012 we entered into a $2.1 billion unsecured Senior Bridge Term Loan Agreement (“2013 Bridge Loan”). In February 2013, we reduced the 2013 Bridge Loan commitment to $900 million. On February 22, 2013, we borrowed $900 million under the 2013 Bridge Loan, with such proceeds and cash on hand were used to redeem the assumed debt from PSS World Medical and pay the equity shareholders of PSS World Medical. On March 8, 2013, we repaid the 2013 Bridge Loan borrowings with funds obtained from the issuance of long-term debt and the bridge loan agreement was subsequently terminated. During the time it was outstanding, the 2013 Bridge Loan borrowings bore interest at 1.20% per annum, based on the London Interbank Offered Rate plus a margin based on the Company’s credit rating. Interest expense for 2013 included $11 million of fees related to the 2013 Bridge Loan.
	Celesio Debt
	Upon the acquisition of Celesio, as required, we consolidated Celesio’s outstanding debt arrangements:
	•	Accounts receivable factoring facility arrangements with a committed balance of $308 million. Transactions under these facilities are accounted for as secured borrowings with interest rates ranging 1.33% to 2.31%. These facilities will expire through September 2015 and Celesio may renew certain facilities before their expiration. Between February 7, 2014 and March 31, 2014, Celesio borrowed and repaid $570 million and $575 million under these facilities. At March 31, 2014, there were $246 million in secured borrowings and related securitized accounts receivable outstanding under these facilities, which were included in short-term borrowings and receivables in the consolidated balance sheets.
	•	Bilateral credit lines with a total committed balance of $1,662 million. As of March 31, 2014, there were $100 million and $88 million in outstanding short-term and long-term borrowings with interest payable monthly and principal payments due through October 31, 2023. The outstanding long-term borrowings are included in the caption “Bank liabilities and other” within the long-term debt table. Bank liabilities also include Celesio’s $100 million term loan outstanding as of March 31, 2014, with a current variable interest rate of 2.35% and principal repayments due through December 15, 2019. Celesio also has a syndicated €500 million five-year senior unsecured revolving credit facility, which expires in February 2018. Borrowings under this credit facility bear interest based on the Euro Interbank Offered Rate plus an agreed margin. From February 7, 2014 through March 31, 2014, there were no amounts outstanding under this credit facility.
	•	Convertible bonds consisting of 1,857 of 2014 Bonds and 1,104 of 2018 Bonds held by third parties as of the Acquisition date, totaling $344 million as of the Acquisition date. As previously disclosed in Financial Note 2, “Business Combinations,” these bonds were either converted to Celesio common shares or redeemed in cash between February 7, 2014 and March 31, 2014. At March 31, 2014, a total of $5 million of 2014 Bonds and 2018 Bonds were outstanding and included in the caption “Bank liabilities and other” within the long-term debt table.
	•	Promissory notes, with interest rates ranging from 1.23% to 5.35%, original maturities of 4-7 years and are due through June 17, 2019. At March 31, 2014, $297 million of promissory notes were outstanding.
	•	Corporate bonds consisting of 4.00% bonds due October 18, 2016 and 4.50% bonds due April 26, 2017. Interest on these bonds is due annually each year. At March 31, 2014, $507 million and $737 million of the 4.00% and 4.50% bonds, for a total of $1,244 million, were outstanding. According to certain terms and conditions of these bonds effective May 7, 2014 bondholders have the option to ask for repayment of the bonds at par value plus accrued interest.   If bondholders do not exercise this option by May 19, 2014, the bonds will remain outstanding until their respective maturity dates. Accordingly, as at March 31, 2014, these bonds have been classified as a current liability.   As of May 7, 2014, the fair value of these bonds of $1,272 million was more than their par value of $1,184 million.
	PSS World Medical Debt
	Upon our purchase of PSS World Medical in February 2013, we assumed the outstanding debt of PSS World Medical. Prior to our acquisition, PSS World Medical called for redemption of all of its outstanding 6.375% Senior Notes due 2022. Due to the change in control provisions of the 3.125% Senior Convertible Notes due 2014, the notes were convertible to cash at the option of the note holders. All the note holders opted to receive cash. In the fourth quarter of 2013, we redeemed both of these notes, including accrued interest for $643 million using cash on hand and borrowings under our 2013 PSS Bridge Loan.
	Long-Term Debt
	In connection with the acquisition of Celesio, on March 5, 2014, we issued floating rate notes (“Floating Rate Notes”) due September 10, 2015 in an aggregate principal amount of $400 million, 1.29% notes due March 10, 2017 in an aggregate principal amount of $700 million (“2017 Notes”), 2.28% notes due March 15, 2019 in an aggregate principal amount of $1,100 million (“2019 Notes”), 3.80% notes due March 15, 2024 in an aggregate principal amount of $1,100 million (“2024 Notes”) and 4.88% notes due March 15, 2044 in an aggregate principal amount of $800 million (“2044 Notes”). The Floating Rate Notes bear interest at a floating rate equal to the three-month London Interbank Offered Rate plus 0.40% (0.64% at March 31, 2014) with interest payable quarterly on March 10, June 10, September 10 and December 10 of each year, beginning on June 10, 2014. Interest on the 2017 Notes is payable on March 10 and September 10 of each year, beginning on September 10, 2014. Interest on the 2019 Notes, the 2024 Notes and the 2044 Notes is payable on March 15 and September 15 of each year, beginning on September 15, 2014. We utilized net proceeds, after discounts and offering expenses of $4,068 million from the issuance of these notes (each note constitutes a “Series”) to repay borrowings under the 2014 Bridge Loan.
	On March 8, 2013, we issued 1.40% notes due March 15, 2018 in an aggregate principal amount of $500 million and 2.85% notes due March 15, 2023 in an aggregate principal amount of $400 million. Interest on these notes is payable on March 15 and September 15 of each year beginning on September 15, 2013. We utilized net proceeds, after discounts and offering expenses of $891 million from the issuance of these notes (each note constitutes a “Series”) to repay borrowings under the 2013 Bridge Loan.
	On December 4, 2012, we issued 0.95% notes due December 4, 2015 in an aggregate principal amount of $500 million (“2015 Notes”) and 2.70% notes due December 15, 2022 in an aggregate principal amount of $400 million (“2022 Notes”). Interest on the 2015 Notes is payable on June 4 and December 4 of each year beginning on June 4, 2013 and on the 2022 Notes is payable on June 15 and December 15 of each year beginning on June 15, 2013. We utilized net proceeds, after discounts and offering expenses, of $892 million from the issuance of these notes (each note constitutes a “Series”) for general corporate purposes and replenishing working capital that was used to repay long-term debt that matured.
	Each Series constitutes an unsecured and unsubordinated obligation of the Company and ranks equally with all of the Company’s existing and future unsecured and unsubordinated indebtedness outstanding from time-to-time. Each Series is governed by materially similar indentures and officers’ certificate specifying certain terms of each Series.
	With the exception of the Floating Rate Notes, upon 30 days notice to holders of a Series, we may redeem that Series at any time prior to maturity, in whole or in part, for cash at redemption prices that include accrued and unpaid interest and a make-whole premium, as specified in the indenture and officers’ certificate relating to that Series. In the event of the occurrence of both (1) a change of control of the Company and (2) a downgrade of a Series below an investment grade rating by each of Fitch Ratings, Moody’s Investors Service, Inc. and Standard & Poor’s Ratings Services within a specified period, an offer must be made to purchase that Series from the holders at a price in cash equal to 101% of the then outstanding principal amount of that Series, plus accrued and unpaid interest to, but not including, the date of repurchase. The indenture and the related officers’ certificate for each Series, subject to the exceptions and in compliance with the conditions as applicable, specify that we may not incur liens, enter into sale and leaseback transactions or consolidate, merge or sell all or substantially all of our assets. The indentures also contain customary events of default provisions.
	We repaid our $350 million 6.50% Notes due February 15, 2014 and our $500 million 5.25% Notes due March 1, 2013, at maturity.
	Scheduled future payments of long-term debt are $1,424 million in 2015, $1,535 million in 2016, $1,277 million in 2017, $520 million in 2018, $1,485 million in 2019 and $4,132 million thereafter.
	Accounts Receivable Sales Facility
	We have an Accounts Receivable Sales facility (the “Facility”) with a committed balance of $1.35 billion, although from time-to-time, the available amount of the Facility may be less than $1.35 billion based on accounts receivable concentration limits and other eligibility requirements. Prior to the Celesio acquisition, we amended the Facility to extend the term for an additional year, increased the maximum debt to capital ratio from 56.5% to 65% and added an extended cure period with respect to defaults under the facility relating to Celesio. The Facility will expire in November 2014 and we anticipate renewing the Facility before its expiration.
	In 2014, 2013 and 2012, we borrowed $550 million $1,325 million and $400 million under the Facility and we repaid $550 million, $1,725 million and nil. At March 31, 2014 and March 31, 2013, there were no secured borrowings and related securitized accounts receivable outstanding under the Facility.
	The Facility contains requirements relating to the performance of the accounts receivable and covenants relating to the Company. If we do not comply with these covenants, our ability to use the Facility may be suspended and repayment of any outstanding balances under the Facility may be required. At March 31, 2014 and March 31, 2013, we were in compliance with all covenants.
	Revolving Credit Facility
	We have a syndicated $1.3 billion five-year senior unsecured revolving credit facility, which expires in September 2016. Prior to the Celesio acquisition, we amended this facility to increase the maximum debt to capital ratio from 56.5% to 65%, and added an extended cure period with respect to defaults under the credit facility relating to Celesio. Borrowings under this renewed credit facility bear interest based upon either the London Interbank Offered Rate or a prime rate. There were no borrowings under this credit facility during 2014, 2013 and 2012. As of March 31, 2014 and 2013, there were no borrowings outstanding under this credit facility.
	Commercial Paper
	There were no commercial paper issuances during 2014, 2013 and 2012 and no amounts outstanding at March 31, 2014 and 2013.
	Debt Covenants
	Our various borrowing facilities and long-term debt are subject to certain covenants. Our principal debt covenant is our U. S. dollar denominated debt to capital ratio under our $1.3 billion unsecured revolving credit facility, which cannot exceed 65%. For the purpose of calculating this ratio, borrowings under the $1.35 billion Accounts Receivable Sales facility are excluded. If we exceed this ratio, repayment of debt outstanding under the revolving credit facility could be accelerated. As of March 31, 2014, we were in compliance with our financial covenants.

Variable_Interest_Entities

Variable Interest Entities	12 Months Ended
	Mar. 31, 2014
Variable Interest Entity, Not Primary Beneficiary, Disclosures [Abstract]	'
Variable Interest Entities	'
	Variable Interest Entities
	Consolidated Variable Interest Entities
	We consolidate VIE’s when we have the power to direct the activities that most significantly impact the entity’s economic performance, as well as the obligation to absorb losses or right to receive benefits of the entity, and as a result we are considered to be the primary beneficiary of these entities. In addition to the consolidation of certain VIEs in our specialty health practices, as a result of our acquisition of Celesio, we have interests in seven new consolidated VIE’s. These Celesio VIEs are single-lessee leasing entities in which Celesio as the lessee has the majority of the risk of the leased assets through the minimum lease payments owed by Celesio to the VIEs. As a result of absorbing this risk, the leases provide Celesio with power over the operations of the leased properties as well as the obligation to absorb losses or right to receive benefits of the entity. Consolidated VIEs have an immaterial impact on our consolidated statements of operations and cash flows. Total assets and liabilities included in our consolidated balance sheet for these VIEs were $160 million and $75 million at March 31, 2014.
	Investments in Unconsolidated Variable Interest Entities
	We are involved with VIEs, which we do not consolidate because we do not have the power to direct the activities that most significantly impact their economic performance and thus are not considered the primary beneficiary of the entities. Our relationships include equity investments, lending, leasing, contractual or other relationships with the VIEs. Our most significant relationships are with oncology and other specialty practices. Under these practice arrangements, we generally own or lease all of the real estate and the equipment used by the affiliated practices and manage the practices’ administrative functions. As a result of our acquisition of Celesio, we also have relationships with certain pharmacies in Europe with whom we may provide financing, have equity ownership and/or a supply agreement whereby we supply the vast majority of the pharmacies’ purchases. Our maximum exposure to loss (regardless of probability) as a result of all unconsolidated VIEs was $1.2 billion and $1.1 billion at March 31, 2014 and 2013, which primarily represents the value of intangible assets related to service agreements and lease and loan receivables. These amounts exclude the customer loan guarantees discussed in Financial Note 21, “Financial Guarantees and Warranties.” We believe that there is no material loss exposure on these assets or from these relationships.

Pension_Benefits

Pension Benefits (Pension Plans Excluding Other Postretirement Benefit Plans [Member])	12 Months Ended
	Mar. 31, 2014
Pension Plans Excluding Other Postretirement Benefit Plans [Member]	'
Defined Benefit Plan Disclosure [Line Items]	'
Pension Benefits	'
	Pension Benefits
	We maintain a number of qualified and nonqualified defined benefit pension plans and defined contribution plans for eligible employees.
	Defined Benefit Pension Plans
	Eligible U.S. employees who were employed by the Company as of December 31, 1995 are covered under the Company-sponsored defined benefit retirement plan. In 1997, the plan was amended to freeze all plan benefits as of December 31, 1996. Benefits for the defined benefit retirement plan are based primarily on age of employees at date of retirement, years of creditable service and the average of the highest 60 months of pay during the 15 years prior to the plan freeze date. We also have defined benefit pension plans for eligible employees outside of the U.S., as well as an unfunded nonqualified supplemental defined benefit plan for certain U.S. executives. Most of the non-U.S. defined benefit pension plans cover employees located in Germany, Norway and the United Kingdom.
	Celesio has defined benefit pension plans for eligible employees located predominately in Germany, Norway and the United Kingdom. Upon the acquisition of Celesio, as required, we consolidated Celesio’s pension assets and obligations on our consolidated balance sheet. Benefits for these plans are based primarily on each employee’s final salary, with annual adjustments for inflation. The obligations in Norway are largely related to the state-regulated pension plan which is managed by the Norwegian Public Service Pension Fund (“SPK”). According to the terms of the SPK, the plan assets of state regulated plans in Norway must correspond very closely to the pension obligation calculated using the principles codified in Norwegian law. The shortfall may not exceed 1% of the obligation. If the shortfall exceeds this threshold, it must be remedied within 2 years. In the United Kingdom, several Celesio subsidiaries participate in a joint pension plan. This plan is largely funded by contractual trust arrangements that hold Company assets that may only be used to pay pension obligations. The Trustee Board decides on the minimum contribution to the plan in association with selected employees of the entity. A valuation is performed at regular intervals in order to determine the amount of the contribution and to ensure that the minimum contribution is made. The pension obligation in Germany is unfunded with the exception of the contractual trust arrangement used to fund pensions of Celesio’s Management Board.
	Defined benefit plan assets and obligations are measured as of the Company’s fiscal year-end.
	The net periodic expense, which includes net pension expense for Celesio since the date of acquisition, for our pension plans is as follows:
		U.S. Plans											Non-U.S. Plans
		Years Ended March 31,											Years Ended March 31,
	(In millions)	2014				2013				2012			2014				2013			2012
	Service cost - benefits earned during the year	$	4			$	4			$	4		$	6			$	3		$	3
	Interest cost on projected benefit obligation	19				21				24			11				7			7
	Expected return on assets	(20		)		(20		)		(23		)	(12		)		(8		)	(8		)
	Amortization of unrecognized actuarial loss, prior service costs and net transitional obligation	32				28				24			4				4			3
	Curtailment gain	—				—				—			(1		)		—			—
	Net periodic pension expense	$	35			$	33			$	29		$	8			$	6		$	5
	The projected unit credit method is utilized in measuring net periodic pension expense over the employees’ service life for the pension plans. Unrecognized actuarial losses exceeding 10% of the greater of the projected benefit obligation or the market value of assets are amortized straight-line over the average remaining future service periods.
	Information regarding the changes in benefit obligations and plan assets for our pension plans is as follows:
		U.S. Plans								Non-U.S. Plans
		Years Ended March 31,								Years Ended March 31,
	(In millions)	2014				2013				2014			2013
	Change in benefit obligations
	Benefit obligation at beginning of period (1)	$	580			$	527			$	156		$	143
	Service cost	4				4				6			3
	Interest cost	19				21				11			7
	Actuarial (gain) loss	(24		)		58				15			15
	Benefit payments	(30		)		(29		)		(12		)	(6		)
	Amendments	(9		)		—				—			—
	Acquisitions	—				—				740			—
	Foreign exchange impact and other	—				(1		)		18			(6		)
	Benefit obligation at end of period (1)	$	540			$	580			$	934		$	156
	Change in plan assets
	Fair value of plan assets at beginning of period	$	290			$	284			$	135		$	126
	Actual return on plan assets	28				19				11			12
	Employer and participant contributions	12				17				12			8
	Benefits paid	(30		)		(29		)		(10		)	(6		)
	Acquisitions	—				—				426			—
	Foreign exchange impact and other	—				(1		)		16			(5		)
	Fair value of plan assets at end of period	$	300			$	290			$	590		$	135
	Funded status at end of period	$	(240	)		$	(290	)		$	(344	)	$	(21	)
	Amounts recognized on the balance sheet
	Current liabilities	$	(13	)		$	(3	)		$	(9	)	$	—
	Long-term liabilities	(227		)		(287		)		(335		)	(21		)
	Total	$	(240	)		$	(290	)		$	(344	)	$	(21	)
	-1	The benefit obligation is the projected benefit obligation.
	The projected and accumulated benefit obligations for our pension plans increased significantly from last year due to the acquisition of Celesio. The following table provides the projected benefit obligation, accumulated benefit obligation and fair value of plan assets for all our pension plans with an accumulated benefit obligation in excess of plan assets.
		U.S. Plans								Non-U.S. Plans
		March 31,								March 31,
	(In millions)	2014				2013				2014			2013
	Projected benefit obligation	$	540			$	580			$	934		$	156
	Accumulated benefit obligation	540				579				894			154
	Fair value of plan assets	300				290				590			135
	Amounts recognized in accumulated other comprehensive income (pre-tax) consist of:
		U.S. Plans								Non-U.S. Plans
		March 31,								March 31,
	(In millions)	2014				2013				2014			2013
	Net actuarial loss	$	188			$	251			$	71		$	59
	Prior service (credit) cost	(7		)		2				—			(2		)
	Total	$	181			$	253			$	71		$	57
	Other changes in accumulated other comprehensive income (pre-tax) during the reporting periods were as follows:
		U.S. Plans											Non-U.S. Plans
		Years Ended March 31,											Years Ended March 31,
	(In millions)	2014				2013				2012			2014				2013			2012
Net actuarial (gain) loss	$	(31	)		$	59			$	42		$	12			$	11		$	19
Prior service credit	(8		)		—				—			—				—			—
Amortization of:
Net actuarial loss	(32		)		(27		)		(23		)	(4		)		(4		)	(2		)
Prior service (cost) credit	—				(1		)		(1		)	2				—			(1		)
Foreign exchange impact and other	(1		)		—				—			4				(4		)	—
Total recognized in other comprehensive loss (income)	$	(72	)		$	31			$	18		$	14			$	3		$	16
We expect to amortize $7 million of prior service credit and $31 million of actuarial loss for the pension plans from stockholders’ equity to pension expense in 2015. Comparable 2014 amounts were $36 million of actuarial loss and $2 million of prior service credit.
Projected benefit obligations relating to our unfunded U.S. plans were $188 million and $205 million at March 31, 2014 and 2013. Pension obligations for our unfunded plans are based on the recommendations of independent actuaries. Projected benefit obligations relating to our unfunded non-U.S. plans were $260 million and $7 million at March 31, 2014 and 2013. Funding obligations for our non-U.S. plans vary based on the laws of each non-U.S. jurisdiction.
Expected benefit payments, including assumed executive lump sum payments, for our pension plans are as follows: $84 million, $190 million, $74 million, $86 million and $105 million for 2015 to 2019 and $413 million for 2020 through 2024. Expected benefit payments are based on the same assumptions used to measure the benefit obligations and include estimated future employee service. Expected contributions to be made for our pension plans are $67 million for 2015.
Weighted-average assumptions used to estimate the net periodic pension expense and the actuarial present value of benefit obligations were as follows:
	U.S. Plans									Non-U.S. Plans
	Years Ended March 31,									Years Ended March 31,
	2014			2013			2012			2014		2013			2012
Net periodic pension expense
Discount rates	3.39	%		4.11	%		4.82	%		3.95	%	4.5	%		5.42	%
Rate of increase in compensation	4			4			4			2.66		3.1			3.45
Expected long-term rate of return on plan assets	7.25			7.25			8			5.71		6.13			6.42
Benefit obligation
Discount rates	3.58	%		3.4	%		4.15	%		3.92	%	4.1	%		4.51	%
Rate of increase in compensation	4			4			4			3.27		3.05			3.06
Our defined benefit pension plan liabilities are valued using a discount rate based on a yield curve developed from a portfolio of high quality corporate bonds rated AA or better whose maturities are aligned with the expected benefit payments of our plans. For March 31, 2014, our U.S. defined benefit liabilities are valued using a weighted average discount rate of 3.58%, which represents an increase of 18 basis points from our 2013 weighted-average discount rate of 3.40%. Our non-U.S defined benefit pension plan liabilities are valued using a weighted-average discount rate of 3.92%.
Sensitivity to changes in the weighted-average discount rate for our pension plans is as follows:
	U.S. Plans						Non-U.S. Plans
(In millions)	One Percentage			One Percentage			One Percentage			One Percentage
	Point Increase			Point Decrease			Point Increase			Point Decrease
Increase (decrease) on projected benefit obligation	$	-35		$	40		$	-97		$	119
Increase (decrease) on net periodic pension cost		-2			2			-3			4
Plan Assets
Investment Strategy: The overall objective for U. S. pension plan assets is to generate long-term investment returns consistent with capital preservation and prudent investment practices, with a diversification of asset types and investment strategies. Periodic adjustments are made to provide liquidity for benefit payments and to rebalance plan assets to their target allocations.
The target allocations for U.S. plan assets at March 31, 2014 and 2013 are 50% equity investments, 45% fixed income investments including cash and cash equivalents and 5% real estate. Equity investments include common stock, preferred stock, and equity commingled funds. Fixed income investments include corporate bonds, government securities, mortgage-backed securities, asset-backed securities, other directly held fixed income investments, and fixed income commingled funds. The real estate investment is in a commingled real estate fund.
For both our and Celesio’s plan assets outside of the U.S., the investment strategies are subject to local regulations and the asset/liability profiles of the plans in each individual country. Plan assets of the non-U.S. plans are broadly invested in a manner appropriate to the nature and duration of the expected future retirement benefits payable under the plans. Plan assets are primarily invested in high-quality corporate and government bond funds and equity securities. Assets are properly diversified to avoid excessive reliance on any particular asset, issuer or group of undertakings so as to avoid accumulations of risk in the portfolio as a whole.
We develop the expected long-term rate of return assumption based on the projected performance of the asset classes in which plan assets are invested. The target asset allocation was determined based on the liability and risk tolerance characteristics of the plans and at times may be adjusted to achieve overall investment objectives.
Fair Value Measurements: The following tables represent our pension plan assets as of March 31, 2014 and 2013, using the fair value hierarchy by asset class. The fair value hierarchy has three levels based on the reliability of the inputs used to determine fair value. Level 1 refers to fair values determined based on unadjusted quoted prices in active markets for identical assets. Level 2 refers to fair values estimated using significant other observable inputs and Level 3 includes fair values estimated using significant unobservable inputs.
	U.S. Plans															Non-U.S. Plans
	March 31, 2014															March 31, 2014
(In millions)	Level 1				Level 2				Level 3			Total				Level 1			Level 2			Level 3		Total
Cash and cash equivalents	$	8			$	—			$	—		$	8			$	7		$	—		$	—	$	7
Equity securities:
Common and preferred stock	19				—				—			19				—			—			—		—
Equity commingled funds	—				132				—			132				6			157			—		163
Fixed income securities:
Government securities	—				7				—			7				4			—			—		4
Corporate bonds	—				22				—			22				6			236			—		242
Mortgage-backed securities	—				10				—			10				—			—			—		—
Asset-backed securities and other	—				22				—			22				—			—			—		—
Fixed income commingled funds	—				63				—			63				—			45			—		45
Other:
Real estate funds	—				—				16			16				—			19			7		26
Other commingled funds	—				—				—			—				3			49			—		52
Other	—				—				—			—				—			46			5		51
Total	$	27			$	256			$	16		299				$	26		$	552		$	12	590
Receivables (1)												1												—
Total												$	300											$	590
-1	Represents pending trades at March 31, 2014.
	U.S. Plans															Non-U.S. Plans
	March 31, 2013															March 31, 2013
(In millions)	Level 1				Level 2				Level 3			Total				Level 1			Level 2			Level 3		Total
Cash and cash equivalents	$	—			$	8			$	—		$	8			$	3		$	—		$	—	$	3
Equity securities:
Common and preferred stock	20				—				—			20				—			—			—		—
Equity commingled funds	—				127				—			127				—			82			—		82
Fixed income securities:
Government securities	—				12				—			12				—			—			—		—
Corporate bonds	—				19				—			19				—			9			—		9
Mortgage-backed securities	—				6				—			6				—			—			—		—
Asset-backed securities and other	—				22				—			22				—			—			—		—
Fixed income commingled funds	—				61				—			61				—			36			—		36
Other:
Real estate funds	—				—				14			14				—			—			5		5
Total	$	20			$	255			$	14		289				$	3		$	127		$	5	135
Receivables (1)												1												—
Total												$	290											$	135
-1	Represents pending trades at March 31, 2013.
Cash and cash equivalents - Cash and cash equivalents include short-term investment funds that maintain daily liquidity and aim to have constant unit values of $1.00. The funds invest in short-term fixed income securities and other securities with debt-like characteristics emphasizing short-term maturities and high credit quality. Directly held cash and cash equivalents are classified as Level 1 investments. Cash and cash equivalents include money market funds and other commingled funds, which have daily net asset values derived from the underlying securities; these are classified as Level 1 or Level 2 investments.
Common and preferred stock - This investment class consists of common and preferred shares issued by U.S. and non-U.S. corporations. Common shares are traded actively on exchanges and price quotes are readily available. Preferred shares may not be actively traded. Holdings of common shares are generally classified as Level 1 investments. Preferred shares are classified as Level 2 investments.
Equity commingled funds - Some equity investments are held in commingled funds, which have daily net asset values derived from quoted prices for the underlying securities in active markets; these are classified as Level 1 or Level 2 investments.
Fixed income securities - Government securities consist of bonds and debentures issued by central governments or federal agencies; corporate bonds consist of bonds and debentures issued by corporations; mortgage-backed securities consist of debt obligations secured by a mortgage or pool of mortgages; and asset-backed securities primarily consist of debt obligations secured by an asset or pool of assets other than mortgages. Inputs to the valuation methodology include quoted prices for similar assets in active markets, and inputs that are observable for the asset, either directly or indirectly, for substantially the full term of the asset. Multiple prices and price types are obtained from pricing vendors whenever possible, enabling cross-provider price validations. Fixed income securities are generally classified as Level 1 or Level 2 investments.
Fixed income commingled funds - Some fixed income investments are held in commingled funds, which have daily net asset values derived from the underlying securities; these are classified as Level 2 investments.
Real estate funds - The value of the real estate funds is reported by the fund manager and is based on a valuation of the underlying properties. Inputs used in the valuation include items such as cost, discounted future cash flows, independent appraisals and market based comparable data. The real estate funds are classified as Level 2 and Level 3 investments.
Other commingled funds - The other commingled funds are invested in equities, bonds, commodities, other alternative investments and cash and cash equivalents. These funds are valued based on the weekly net asset values derived from the quoted prices for the underlying securities in active markets and, for alternative investments, based on other valuation techniques. Other commingled funds are classified as Level 1 or Level 2 investments.
Other - At March 31, 2014, this includes $46 million of plan asset value relating to the Norwegian Public Service Pension Fund (“SPK”). In principle, the SPK is organized as a pay-as-you-go system guaranteed by the Norwegian government as it holds no Company-owned assets to back the pension liabilities. The Company pays a pension premium used to fund the plan, which is paid directly to the Norwegian government and is accounted for as governmental income in the annual budget for Norway. To be able to report back plan asset values for the participating employers, SPK has established an annual account for each participating employer to keep track of the financial status of the plan, including managing the contributions and the payments. Further, the investment return credited to this account is determined annually by the SPK based on the performance of long-term government bonds.
The following table represents a reconciliation of Level 3 plan assets held during the years ended March 31, 2014 and 2013:
	U.S. Plans											Non-U.S. Plans
(In millions)	Real Estate				Other				Total			Real				Other			Total
	Funds											Estate
												Funds
Balance at March 31, 2012	$	12			$	—			$	12		$	5			$	—		$	5
Unrealized gain on plan assets still held	1				—				1			—				—			—
Purchases, sales and settlements	1				—				1			—				—			—
Balance at March 31, 2013	$	14			$	—			$	14		$	5			$	—		$	5
Acquisitions	—				—				—			1				5			6
Unrealized gain on plan assets still held	2				—				2			1				—			1
Purchases, sales and settlements	—				—				—			—				—			—
Balance at March 31, 2014	$	16			$	—			$	16		$	7			$	5		$	12
Multiemployer Plans
The Company contributes to a number of multiemployer pension plans under the terms of collective-bargaining agreements that cover union-represented employees in the U.S. In 2014, as a result of our acquisition of Celesio, we also contribute to the Pensjonsordningen for Apoteketaten (“POA”), a mandatory multiemployer pension scheme for our Pharmacy employees in Norway, managed by the association of Norwegian Pharmacies.
The risks of participating in these multiemployer plans are different from single-employer pension plans in the following aspects: (i) assets contributed to the multiemployer plan by one employer may be used to provide benefits to employees of other participating employers; (ii) if a participating employer stops contributing to the plan, the unfunded obligations of the plan may be borne by the remaining participating employers; and (iii) if the Company chooses to stop participating in some of its multiemployer plans, the Company may be required to pay those plans an amount based on the underfunded status of the plan, referred to as a withdrawal liability. Actions taken by other participating employers may lead to adverse changes in the financial condition of a multiemployer benefit plan and our withdrawal liability and contributions may increase.
Contributions and amounts accrued for U.S. Plans were not material for the years ended March 31, 2014, 2013, and 2012. Celesio’s contributions to the POA exceeding 5% of total plan contributions were $5 million since our acquisition of Celesio in February 2014. Based on actuarial calculations, we estimate Celesio’s funded status to be less than 65% as of March 31, 2014. No amounts were accrued for liability associated with the POA as Celesio has no intention to withdraw from the plan.
Defined Contribution Plans
We have a contributory profit sharing investment plan (“PSIP”) for U.S. employees not covered by collective bargaining agreements. Eligible employees may contribute to the PSIP up to 75% of their eligible compensation on a pre-tax basis not to exceed IRS limits. The Company makes matching contributions in an amount equal to 100% of the employee’s first 3% of pay contributed and 50% for the next 2% of pay contributed. The Company also may make an additional annual matching contribution for each plan year to enable participants to receive a full match based on their annual contribution. Contribution expenses for the PSIP were $71 million, $61 million and $58 million for the years ended March 31, 2014, 2013, and 2012.

Postretirement_Benefits

Postretirement Benefits (Other Postretirement Benefit Plan, Defined Benefit [Member])	12 Months Ended
	Mar. 31, 2014
Other Postretirement Benefit Plan, Defined Benefit [Member]	'
Defined Benefit Plan Disclosure [Line Items]	'
Postretirement Benefits	'
	Postretirement Benefits
	We maintain a number of postretirement benefits, primarily consisting of healthcare and life insurance (“welfare”) benefits, for certain eligible U.S. employees. Eligible employees consist of those who retired before March 31, 1999 and those who retired after March 31, 1999, but were an active employee as of that date, after meeting other age-related criteria. We also provide postretirement benefits for certain U.S. executives. Defined benefit plan obligations are measured as of the Company’s fiscal year-end.
	The net periodic expense for our postretirement welfare benefits is as follows:
		Years Ended March 31,
	(In millions)	2014			2013			2012
	Service cost - benefits earned during the year	$	2		$	2		$	2
	Interest cost on accumulated benefit obligation	5			6			7
	Amortization of unrecognized actuarial gain and prior service credit	(1		)	(2		)	(1		)
	Curtailment gain	(2		)	—			—
	Net periodic postretirement expense	$	4		$	6		$	8
	Information regarding the changes in benefit obligations for our postretirement welfare plans is as follows:
		Years Ended March 31,
	(In millions)	2014			2013
	Benefit obligation at beginning of period	$	131		$	144
	Service cost	2			2
	Interest cost	5			6
	Actuarial gain	(2		)	(9		)
	Benefit payments	(15		)	(12		)
	Curtailment gain	(2		)	—
	Benefit obligation at end of period	$	119		$	131
	The components of the amount recognized in accumulated other comprehensive income for the Company’s other postretirement benefits at March 31, 2014 and 2013 were net actuarial gains of $8 million and $6 million and net prior service credits of $1 million and $1 million. Other changes in benefit obligations recognized in other comprehensive income were net actuarial gains of $2 million, $7 million and $3 million in 2014, 2013 and 2012.
	We estimate that the amortization of the actuarial gain from stockholders’ equity to other postretirement expense in 2015 will be $4 million. Comparable 2014 amount was $1 million.
	Other postretirement benefits are funded as claims are paid. Expected benefit payments for our postretirement welfare benefit plans are as follows: $10 million annually for 2015 to 2019 and $45 million cumulatively for 2020 through 2024. Expected benefit payments are based on the same assumptions used to measure the benefit obligations and include estimated future employee service. Expected contributions to be made for our postretirement welfare benefit plans are $11 million for 2015.
	Weighted-average discount rates used to estimate postretirement welfare benefit expenses were 3.84%, 4.44% and 5.09% for 2014, 2013 and 2012. Weighted-average discount rates for the actuarial present value of benefit obligations were 4.08%, 3.84% and 4.44% for 2014, 2013 and 2012.
	Actuarial gain or loss for the postretirement welfare benefit plan is amortized to income or expense over a three-year period. The assumed healthcare cost trends used in measuring the accumulated postretirement benefit obligation were 7.00% and 7.50% for prescription drugs, 7.50/7.00% and 7.50/7.25% for ages pre-65/post-65 medical and 5.00% and 5.25% for dental in 2014 and 2013. For 2014, 2013 and 2012, a one-percentage-point increase or decrease in the assumed healthcare cost trend rate would not have a material impact on the postretirement benefit obligations.
	Pursuant to various collective bargaining agreements, we contribute to multiemployer health and welfare plans that cover union-represented employees. Our liability is limited to the contractual dollar obligations set forth by the collective bargaining agreements. Contributions to the plans and amounts accrued were not material for the years ended March 31, 2014, 2013, and 2012.

Hedging_Activities

Hedging Activities	12 Months Ended
	Mar. 31, 2014
Derivative Instruments and Hedging Activities Disclosure [Abstract]	'
Hedging Activities	'
	Hedging Activities
	In the normal course of business, we are exposed to interest rate changes and foreign currency fluctuations. At times we limit these risks through the use of derivatives such as interest rate swaps and forward foreign exchange contracts. In accordance with our policy, derivatives are only used for hedging purposes. We do not use derivatives for trading or speculative purposes.
	Foreign currency rate risk
	Prior to the acquisition of Celesio, the majority of our operations were conducted in U. S. dollars; however, certain assets and liabilities, revenues and expense and purchasing activities were incurred in and exposed to other currencies. We have established certain foreign currency rate risk programs that manage the impact of foreign currency fluctuation. These programs are utilized on a transactional basis when we consider there to be a risk in fair value or volatility in cash flows. These programs reduce but do not entirely eliminate foreign currency rate risk.
	Over the last three years, we have entered into forward contracts and a foreign currency option to hedge against cash flows denominated primarily in Canadian dollars and British pounds. At March 31, 2014, forward contracts having a total notional value of $463 million were designated for hedge accounting. These contracts will mature between March 2015 and March 2020. Changes in the fair values for contracts designated for hedge accounting were recorded to accumulated other comprehensive income and reclassified into earnings in the same period in which the hedged transaction affects earnings; amounts recorded to earnings for these contracts were not material in 2014, 2013 and 2012. Changes in the fair values for contracts not designated for hedge accounting were recorded directly to earnings; amounts recorded to earnings for these contracts were not material in 2014, 2013 and 2012.
	Celesio has a number of forward contracts to hedge against cash flows denominated primarily in British pounds and other European currencies. The contracts will mature from April 1, 2014 to January 2015. None of these contracts were designated for hedge accounting and accordingly, changes in the fair value of these contracts are recorded directly in earnings. At March 31, 2014, the total notional values of these contracts was $1,091 million. Amounts recorded to earnings were not material for 2014.
	Interest rate risk
	Celesio also has interest rate swaps to hedge the interest rate risk associated with Celesio’s variable rate debt. Interest rate swaps are used to modify the market risk exposures in connection with the variable rate debt to achieve primarily Euro dollar fixed rate interest expense. The interest rate swap transactions generally involve the exchange of floating or fixed interest payments and have a gross notional of $96 million at March 31, 2014. The interest rate swaps will mature during the first half of 2015. These contracts are not designated for hedge accounting and, accordingly, changes in the fair value of the swaps were recorded directly in earnings. Amounts recorded to earnings were not material for 2014.
	Information regarding the fair value of derivatives on a gross basis is as follows:
		Balance Sheet	31-Mar-14						31-Mar-13
		Caption	Fair Value of				U.S. Dollar Notional		Fair Value of				U.S Dollar Notional
			Derivative						Derivative
	(In millions)		Asset		Liability				Asset		Liability
	Derivatives designated for hedge accounting
	Foreign exchange	Prepaid expenses and other	$	4	$	—	$	64	$	—	$	—	$	—
	contracts (current)
	Foreign exchange	Other assets	27		—		399		5		—		463
	contracts (non-current)
	Foreign exchange	Other accrued liabilities	—		—		—		—		1		41
	contracts (current)
	Total		$	31	$	—			$	5	$	1
	Derivatives not designated for hedge accounting
	Foreign exchange	Prepaid expenses and other	$	2	$	—	$	255	$	5	$	—	$	177
	contracts (current)
	Foreign exchange	Other accrued liabilities	—		13		836		—		—		—
	contracts (current)
	Interest rate swap contracts (current)	Other accrued liabilities	—		1		96		—		—		—
	Total		$	2	$	14			$	5	$	—
	Refer to Financial Note 19, “Fair Value Measurements,” for more information on these recurring fair value measurements.

Fair_Value_Measurements

Fair Value Measurements	12 Months Ended
	Mar. 31, 2014
Fair Value Disclosures [Abstract]	'
Fair Value Measurements	'
	Fair Value Measurements
	Fair value is defined as the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date. The analysis of fair value is conducted by our accounting and finance personnel who organizationally report to the Chief Financial Officer. There is a three-level hierarchy that prioritizes the inputs used in determining fair value by their reliability and preferred use, as follows:
	Level 1 - Valuations based on quoted prices in active markets for identical assets or liabilities.
	Level 2 - Valuations based on quoted prices in active markets for similar assets and liabilities, quoted prices for identical or similar assets or liabilities in inactive markets, or other inputs that are observable or can be corroborated by observable market data.
	Level 3 - Valuations based on inputs that are both significant to the fair value measurement and unobservable.
	At March 31, 2014 and 2013, the carrying amounts of cash, certain cash equivalents, restricted cash, receivables, drafts and accounts payable, short-term borrowings, promissory notes and other current liabilities approximated their estimated fair values because of the short maturity of these financial instruments.
	Our long-term debt and other financing arrangements are carried at amortized cost. The carrying amounts and estimated fair values of these liabilities were $10.4 billion and $10.8 billion at March 31, 2014 and $4.9 billion and $5.5 billion at March 31, 2013. The estimated fair values of our long-term debt and other financing were determined using quoted market prices in a less active market and other observable inputs from available market information, which are considered to be Level 2 inputs, and may not be representative of actual values that could have been realized or that will be realized in the future.
	Assets Measured at Fair Value on a Recurring Basis
	Our financial assets measured at fair value on a recurring basis consist of the following:
		March 31, 2014								March 31, 2013
	(In millions)	Level 1		Level 2		Level 3		Total		Level 1		Level 2		Level 3		Total
	Cash Equivalents
	Money market funds (1)	$	2,284	$	—	$	—	$	2,284	$	1,036	$	—	$	—	$	1,036
	Time deposits (2)	—		12		—		12		—		95		—		95
	Repurchase agreements (2)	569		—		—		569		447		—		—		447
	Total cash equivalents	$	2,853	$	12	$	—	$	2,865	$	1,483	$	95	$	—	$	1,578
	(1) Gross unrealized gain and losses were not material for the years ended March 31, 2014 and 2013. Based on quoted prices of identical investments.
	(2) The carrying amounts of these cash equivalents approximated their estimated fair values because of their short maturities.
	Fair values of our marketable securities were determined using quoted prices in active markets for identical assets, which are considered Level 1 inputs under the fair value measurements and disclosure guidance. Fair values for our marketable securities were not material at March 31, 2014 and 2013.
	Fair values of our forward foreign currency derivatives were determined using quoted market prices of similar instruments in an active market and other observable inputs from available market information.  These inputs are considered Level 2 under the fair value measurements and disclosure guidance, and may not be representative of actual values that could have been realized or that will be realized in the future. Refer to Financial Note 18, “Hedging Activities,” for more information on our forward foreign currency derivatives.
	There were no transfers between Level 1, Level 2 or Level 3 of the fair value hierarchy during the years ended March 31, 2014 and 2013.
	Assets Measured at Fair Value on a Nonrecurring Basis
	We measure certain long-lived assets at fair value on a nonrecurring basis when they are deemed to be other-than-temporarily impaired. If the cost of an investment exceeds its fair value, we evaluate, among other factors, our intent to hold the investment, general market conditions, the duration and extent to which the fair value is less than cost and the financial outlook for the industry and location. An impairment charge is recorded when the cost of the asset exceeds its fair value and this condition is determined to be other-than-temporary.
	Fiscal 2014
	Impairment of Our International Technology Business:
	As discussed in Financial Note 3, “Discontinued Operations,” during 2014 we recorded an $80 million non-cash pre-tax and after-tax impairment charge to reduce the carrying value of our International Technology business to its estimated fair value, less costs to sell. The impairment charge was primarily the result of the terms of the preliminary purchase offers received for this business during 2014. Accordingly, the fair value measurement is classified as Level 3 in the fair value hierarchy.
	Fiscal 2013
	For the year ended March 31, 2013, assets measured at fair value on a nonrecurring basis consisted of our investment in Nadro and goodwill for a reporting unit within our Technology Solutions segment. Both of these assets were measured using Level 3 inputs.
	Impairment of an Equity Investment:
	As discussed in Financial Note 5, “Impairment and Sale of an Equity Investment,” during 2013 we committed to a plan to sell our investment in Nadro and in the fourth quarter of 2013 recorded an impairment charge of $191 million to reduce the carrying value to fair value. Fair value of our investment in Nadro was determined using income and market valuation approaches. Under the income approach, we used a discounted cash flow (“DCF”) analysis based on estimated future results. This valuation approach is considered a Level 3 fair value measurement due to the use of significant unobservable inputs related to the timing and amount of future cash flows based on projections of revenues and operating costs and discounting those cash flows to their present value. The key inputs and assumptions of the DCF method are the projected cash flows, the terminal value of the business and the discount rate. The key inputs for the market valuation approach were Nadro’s fiscal 2012 unaudited earnings before interest, depreciation and amortization (“EBITDA”) and an EBITDA multiple based on similar guideline U.S. pharmaceutical companies whose securities are actively traded in public markets. This valuation approach is considered a Level 3 fair value measurement. Finally, we evaluated the fair values under both valuation methods and concluded on an average of the two methods. In September 2013, we completed the sale of our 49% interest in Nadro which resulted in no material gain or loss.
	Goodwill:
	As discussed in Financial Note 4, “Asset Impairments and Product Alignment Charges,” in 2013 we recorded a goodwill impairment charge of $36 million in one of Technology Solutions segment’s reporting units. The impairment charge was primarily the result of a significant decrease in estimated revenues for a software product. As required under step two goodwill impairment testing, we determined the fair value of the reporting unit and the fair value of the reporting units’ net assets, excluding goodwill but including any unrecognized intangible assets. The implied fair value of goodwill was then calculated on a residual basis – that is, by subtracting the sum of the fair value of the net assets from the fair value of the reporting unit. The impairment was equal to the carrying amount of goodwill.
	Fair value assessment of the reporting unit as well as the reporting unit’s net assets are considered a Level 3 measurement due to the significance of unobservable inputs developed using company specific information. We used the market approach and income approach (DCF model) to determine the fair value of the reporting unit and a DCF model to determine the fair value of the reporting unit’s most significant assets – intangibles. Additionally, fair values reflect a risk premium to the discount rate due to the uncertainty in forecasting future cash flows.

Lease_Obligations

Lease Obligations	12 Months Ended
	Mar. 31, 2014
Leases, Operating [Abstract]	'
Lease Obligations	'
	Lease Obligations
	We lease facilities and equipment almost solely under operating leases. At March 31, 2014, future minimum lease payments required under operating leases that have initial or remaining noncancelable lease terms in excess of one year for years ending March 31 are:
	(In millions)	Noncancelable
		Operating
		Leases
	2015	$	358
	2016	299
	2017	246
	2018	193
	2019	168
	Thereafter	806
	Total minimum lease payments (1)	$	2,070
	-1	Minimum lease payments have not been reduced by minimum sublease rentals of $44 million due under future noncancelable subleases.
	Rental expense under operating leases was $298 million, $232 million and $229 million in 2014, 2013 and 2012. We recognize rent expense on a straight-line basis over the term of the lease, taking into account, when applicable, lessor incentives for tenant improvements, periods where no rent payment is required and escalations in rent payments over the term of the lease. Deferred rent is recognized for the difference between the rent expense recognized on a straight-line basis and the payments made per the terms of the lease. Remaining terms for facilities leases generally range from one to twelve years, while remaining terms for equipment leases range from one to five years. Most real property leases contain renewal options (generally for five-year increments) and provisions requiring us to pay property taxes and operating expenses in excess of base period amounts. Sublease rental income was not material for 2014, 2013 and 2012.

Financial_Guarantees_and_Warra

Financial Guarantees and Warranties	12 Months Ended
	Mar. 31, 2014
Financial Guarantees And Warranties [Abstract]	'
Financial Guarantees And Warranties	'
	Financial Guarantees and Warranties
	Financial Guarantees
	We have agreements with certain of our customers’ financial institutions, mainly in Canada and Europe, under which we have guaranteed the repurchase of our customers’ inventory or our customers’ debt in the event these customers are unable to meet their obligations to those financial institutions. For our inventory repurchase agreements, among other requirements, inventories must be in resalable condition and any repurchase would be at a discount. The inventory repurchase agreements mostly relate to certain Canadian customers and range from one to two years. Customers’ debt guarantees range from one to fifteen years and are primarily provided to facilitate financing for certain customers. The majority of our customers’ debt guarantees are secured by certain assets of the customer. At March 31, 2014, the maximum amounts of inventory repurchase guarantees and customers’ debt guarantees were $204 million and $272 million, of which $4 million had been accrued. The expirations of these financial guarantees are as follows: $154 million, $31 million, $17 million, $21 million and $37 million from 2015 through 2019 and $216 million thereafter.
	At March 31, 2014, our banks and insurance companies have issued $161 million of standby letters of credit and surety bonds, which were issued on our behalf mostly related to our customer contracts and in order to meet the security requirements for statutory licenses and permits, court and fiduciary obligations and our workers’ compensation and automotive liability programs. Additionally, at March 31, 2014, we have a commitment to contribute up to $40 million to a non-consolidated investment for building and equipment construction.
	Our software license agreements generally include certain provisions for indemnifying customers against liabilities if our software products infringe a third party’s intellectual property rights. To date, we have not incurred any material costs as a result of such indemnification agreements and have not accrued any liabilities related to such obligations.
	In conjunction with certain transactions, primarily divestitures, we may provide routine indemnification agreements (such as retention of previously existing environmental, tax and employee liabilities) whose terms vary in duration and often are not explicitly defined. Where appropriate, obligations for such indemnifications are recorded as liabilities. Because the amounts of these indemnification obligations often are not explicitly stated, the overall maximum amount of these commitments cannot be reasonably estimated. Other than obligations recorded as liabilities at the time of divestiture, we have historically not made material payments as a result of these indemnification provisions.
	Warranties
	In the normal course of business, we provide certain warranties and indemnification protection for our products and services. For example, we provide warranties that the pharmaceutical and medical-surgical products we distribute are in compliance with the U.S. Food, Drug and Cosmetic Act and other applicable laws and regulations. We have received the same warranties from our suppliers, which customarily are the manufacturers of the products. In addition, we have indemnity obligations to our customers for these products, which have also been provided to us from our suppliers, either through express agreement or by operation of law.
	We also provide warranties regarding the performance of software and products we sell. Our liability under these warranties is to bring the product into compliance with previously agreed upon specifications. For software products, this may result in additional project costs, which are reflected in our estimates used for the percentage-of-completion method of accounting for software installation services within these contracts. In addition, most of our customers who purchase our software and automation products also purchase annual maintenance agreements. Revenues from these maintenance agreements are recognized on a straight-line basis over the contract period and the cost of servicing product warranties is charged to expense when claims become estimable. Accrued warranty costs were not material to the consolidated balance sheets.

Other_Commitments_and_Continge

Other Commitments and Contingent Liabilities	12 Months Ended
	Mar. 31, 2014
Commitments and Contingencies Disclosure [Abstract]	'
Other Commitments and Contingent Liabilities	'
	Other Commitments and Contingent Liabilities
	In addition to commitments and obligations in the ordinary course of business, we are subject to various claims, other pending and potential legal actions for damages, investigations relating to governmental laws and regulations and other matters arising out of the normal conduct of our business. As described below, many of these proceedings are at preliminary stages and many seek an indeterminate amount of damages.
	When a loss is considered probable and reasonably estimable, we record a liability in the amount of our best estimate for the ultimate loss. However, the likelihood of a loss with respect to a particular contingency is often difficult to predict and determining a meaningful estimate of the loss or a range of loss may not be practicable based on the information available and the potential effect of future events and decisions by third parties that will determine the ultimate resolution of the contingency. Moreover, it is not uncommon for such matters to be resolved over many years, during which time relevant developments and new information must be reevaluated at least quarterly to determine both the likelihood of potential loss and whether it is possible to reasonably estimate a range of possible loss. When a loss is probable but a reasonable estimate cannot be made, disclosure of the proceeding is provided.
	Disclosure also is provided when it is reasonably possible that a loss will be incurred or when it is reasonably possible that the amount of a loss will exceed the recorded provision. We review all contingencies at least quarterly to determine whether the likelihood of loss has changed and to assess whether a reasonable estimate of the loss or range of loss can be made. As discussed above, development of a meaningful estimate of loss or a range of potential loss is complex when the outcome is directly dependent on negotiations with or decisions by third parties, such as regulatory agencies, the court system and other interested parties. Such factors bear directly on whether it is possible to reasonably estimate a range of potential loss and boundaries of high and low estimates.
	We are party to the legal proceedings described below. Unless otherwise stated, we are currently unable to estimate a range of reasonably possible losses for the unresolved proceedings described below. Should any one or a combination of more than one of these proceedings be successful, or should we determine to settle any or a combination of these matters, we may be required to pay substantial sums, become subject to the entry of an injunction or be forced to change the manner in which we operate our business, which could have a material adverse impact on our financial position or results of operations.
	I. Litigation and Claims
	On April 16, 2013, the Company’s wholly-owned subsidiary, U.S. Oncology, Inc. (“USON”), was served with a third amended qui tam complaint filed in the United States District Court for the Eastern District of New York by two relators, purportedly on behalf of the United States, twenty-one states and the District of Columbia, against USON and five other defendants, alleging that USON solicited and received illegal “kickbacks” from Amgen in violation of the Anti-Kickback Statute, the False Claims Act, and various state false claims statutes, and seeking damages, treble damages, civil penalties, attorneys’ fees and costs of suit, all in unspecified amounts, United States ex rel. Piacentile v. Amgen Inc., et al., (CV 04-3983 (SJ)). Previously, the United States declined to intervene in the case as to all allegations and defendants except for Amgen. On February 5, 2013, the United States filed a motion to dismiss the claims pled against Amgen. On September 30, 2013, the court granted the United States’ motion to dismiss. On April 4, 2014, USON filed a motion to dismiss the claims pled against it. The court has not yet ruled on USON’s motion.
	II. Average Wholesale Price (“AWP”) Litigation
	On May 1, 2013, an action was filed in the United States District Court for the Northern District of California by several Ohio health benefit programs against the Company asserting claims under the federal and Ohio RICO statutes, and seeking damages, treble damages, attorneys’ fees, and costs of suit, all in unspecified amounts, based on the same allegations as the Company’s previously disclosed AWP litigation, Ohio v. McKesson Corporation, et al., (CV-13-2000-SI). The plaintiffs allege that in late 2001, the Company and First DataBank, Inc., a publisher of pharmaceutical pricing information, conspired to improperly raise the published AWP for certain prescription drugs, and that this alleged conduct resulted in higher drug reimbursement payments. On July 12, 2013, the parties filed a stipulation dismissing with prejudice the claims asserted against the Company under the Ohio RICO statutes. On February 28, 2014, the Company entered into a settlement agreement with the plaintiffs. On March 12, 2014, pursuant to a stipulation between the parties and the terms of the parties’ settlement agreement, the court entered an order dismissing this action with prejudice.
	The Company has a reserve relating to AWP public entity claims, which is reviewed at least quarterly and whenever events or circumstances indicate changes, including consideration of the pace and progress of discussions relating to potentially resolving other public entity claims. Pre-tax charges relating to changes in the Company’s AWP litigation reserve, including accrued interest, are recorded in the Distribution Solutions segment. The Company’s AWP litigation reserve is included in other current liabilities in the consolidated balance sheets.
	The following is the activity related to the AWP litigation reserve for the years ended March 31, 2014, 2013 and 2012:
		Years Ended March 31,
	(In millions)	2014			2013			2012
	AWP litigation reserve at beginning of period	$	42		$	453		$	330
	Charges incurred	68			72			149
	Payments made	(105		)	(483		)	(26		)
	AWP litigation reserve at end of period	$	5		$	42		$	453
	The charges for 2014 and 2013 primarily related to state Medicaid and other claims. The charges for 2012 primarily related to the Douglas County, Kansas Action settlement and the state and federal Medicaid claims.
	III. Government Subpoenas and Investigations
	From time-to-time, the Company receives subpoenas or requests for information from various government agencies. The Company generally responds to such subpoenas and requests in a cooperative, thorough and timely manner. These responses sometimes require time and effort and can result in considerable costs being incurred by the Company. Such subpoenas and requests also can lead to the assertion of claims or the commencement of civil or criminal legal proceedings against the Company and other members of the health care industry, as well as to settlements. Examples of such subpoenas and investigations include subpoenas commencing in 2013 from the U.S. Drug Enforcement Administration to certain of the Company’s pharmaceutical distribution facilities seeking information and records about the Company’s distribution of certain controlled substances. The Company is currently responding to these requests. In addition, in the third quarter 2013, the Company was informed of an investigation by the United States Department of Justice through the United States Attorney’s Office for the Middle District of Tennessee. The Company believes that the investigation is focused on distribution procedures with respect to the Vaccine for Children’s Program administered by the Centers for Disease Control and Prevention. In connection with the investigation, the Company has received and has responded to a subpoena seeking information and records from the Company’s Specialty Health business. In the third quarter of 2014, the Company was informed of an investigation by the United States Department of Justice through the United States Attorney’s Office for the Northern District of West Virginia of potential claims under the Comprehensive Drug Abuse Prevention and Control Act.  The Company believes that the investigation is focused on the Company’s pharmaceutical distribution of certain controlled substances by its Landover, Maryland distribution center, which closed in 2012. In addition, in the fourth quarter 2014, the Company was informed of an investigation by the United States Department of Justice through the United States Attorney’s Office for the Eastern District of Tennessee. The Company believes that the investigation is focused on billing and coding services performed by our Technology business. The Company is in the process of providing requested documents.
	IV. Environmental Matters
	Primarily as a result of the operation of the Company’s former chemical businesses, which were fully divested by 1987, the Company is involved in various matters pursuant to environmental laws and regulations. The Company has received claims and demands from governmental agencies relating to investigative and remedial actions purportedly required to address environmental conditions alleged to exist at eight sites where it, or entities acquired by it, formerly conducted operations and the Company, by administrative order or otherwise, has agreed to take certain actions at those sites, including soil and groundwater remediation. In addition, the Company is one of multiple recipients of a New Jersey Department of Environmental Protection Agency directive and a separate United States Environmental Protection Agency directive relating to potential natural resources damages (“NRD”) associated with one of these eight sites. Although the Company’s potential allocation under either directive cannot be determined at this time, it has agreed to participate with a potentially responsible party (“PRP”) group in the funding of certain tasks to support an NRD assessment, the costs of which are reflected in the aggregate estimates set forth below.
	Based on a determination by the Company’s environmental staff, in consultation with outside environmental specialists and counsel, the current estimate of the Company’s probable loss associated with the remediation costs for these eight sites is $7 million, net of approximately $1 million that third parties have agreed to pay in settlement or is expected, based either on agreements or nonrefundable contributions which are ongoing, to be contributed by third parties. The $7 million is expected to be paid out between May 2014 and March 2034. The Company’s estimated probable loss for these environmental matters has been entirely accrued for in the accompanying consolidated balance sheets.
	In addition, the Company has been designated as a PRP under the Superfund law for environmental assessment and cleanup costs as the result of its alleged disposal of hazardous substances at 14 sites. With respect to these sites, numerous other PRPs have similarly been designated and while the current state of the law potentially imposes joint and several liability upon PRPs, as a practical matter, costs of these sites are typically shared with other PRPs. At one of these sites, the United States Environmental Protection Agency has selected a preferred remedy with an estimated cost of approximately $70 million. It is not certain at this point in time what proportion of this estimated liability will be borne by the Company or by the other PRPs. Accordingly, the Company’s estimated probable loss at those 14 sites is approximately $20 million, which has been entirely accrued for in the accompanying consolidated balance sheets. However, it is possible that the ultimate costs of these matters may exceed or be less than the reserves.
	V. Other Matters
	The Company is involved in various other litigation and governmental proceedings, not described above, that arise in the normal course of business. While it is not possible to determine the ultimate outcome or the duration of any such litigation or governmental proceedings, the Company believes, based on current knowledge and the advice of counsel, that such litigation and proceedings will not have a material impact on the Company’s financial position or results of operations.

Stockholders_Equity

Stockholders' Equity	12 Months Ended
	Mar. 31, 2014
Stockholders' Equity Note [Abstract]	'
Stockholders' Equity	'
	Stockholders’ Equity
	Each share of the Company’s outstanding common stock is permitted one vote on proposals presented to stockholders and is entitled to share equally in any dividends declared by the Company’s Board of Directors (the “Board”).
	In July 2013, the quarterly dividend was raised from $0.20 to $0.24 per common share for dividends declared after such date, until further action by the Board. Dividends were $0.92 per share in 2014 and $0.80 per share in 2013 and 2012. The Company anticipates that it will continue to pay quarterly cash dividends in the future.  However, the payment and amount of future dividends remain within the discretion of the Board and will depend upon the Company’s future earnings, financial condition, capital requirements and other factors.
	Share Repurchase Plans
	Stock repurchases may be made from time-to-time in open market transactions, privately negotiated transactions, through accelerated share repurchase (“ASR”) programs, or by any combination of such methods. The timing of any repurchases and the actual number of shares repurchased will depend on a variety of factors, including our stock price, corporate and regulatory requirements, restrictions under our debt obligations and other market and economic conditions.
	Information regarding the share repurchase activity over the last three years is as follows:
		Share Repurchases (1)
	(In millions, except price per share data)		Total		Average Price			Approximate
			Number of Shares Purchased (2) (3)		Paid Per Share			Dollar Value of
								Shares that May
								Yet Be Purchased
								Under the
								Programs
	Balance, March 31, 2011							$	499
	Share repurchase plans approved:
	Apr-11							1,000
	Jan-12							650
	Shares repurchased		20		$	83.47		(1,850		)
	Balance, March 31, 2012							$	299
	Share repurchase plans approved:
	Apr-12							700
	Jan-13							500
	Shares repurchased		13		$	100.82		(1,159		)
	Balance, March 31, 2013							$	340
	Shares repurchased		—		$	—		—
	Balance, March 31, 2014							$	340
	-1	This table does not include shares tendered to satisfy the exercise price in connection with cashless exercises of employee stock options or shares tendered to satisfy tax withholding obligations in connection with employee equity awards.
	-2	All of the shares purchased were part of the publicly announced programs.
	-3	The number of shares purchased reflects rounding adjustments.
	During the fourth quarter of 2013, we retired approximately 2 million shares repurchased for $217 million by the Company.   The retired shares constitute authorized but unissued shares. We elected to allocate any excess of share repurchase price over par value between additional paid-in capital and retained earnings. As such, $195 million was recorded as a decrease to retained earnings.
	Other Comprehensive Income (Loss)
	Information regarding other comprehensive income (loss) including noncontrolling interest, net of tax by component are as follows:
		Years Ended March 31,
	(In millions)	2014			2013			2012
	Foreign currency translation adjustments
	Foreign currency translation adjustments arising during period, net of income tax expense (benefit) of nil, ($2) and $2 (1)	$	9		$	(52	)	$	(56	)
	Reclassified to income statement, net of income tax expense of $24, nil and nil (2)	44			—			—
		53			(52		)	(56		)
	Unrealized losses on cash flow hedges
	Unrealized losses on cash flow hedges arising during period, net of income tax benefit of nil, nil and nil	(6		)	—			(5		)
	Changes in retirement-related benefit plans
	Net actuarial gain (loss) and prior service credit (cost) arising during period, net of income tax (benefit) of $16, ($22) and ($18)	17			(40		)	(38		)
	Amortization of actuarial loss, prior service cost and transition obligation, net of income tax expense of $12, $12 and $9 (3)	22			18			17
	Foreign currency translation adjustments, net of income tax expense of nil, nil and nil	(4		)	4			—
	Reclassified to income statement, net of income tax expense of $1, nil and nil	1			—			—
		36			(18		)	(21		)
	Other Comprehensive Income (Loss), net of tax	$	83		$	(70	)	$	(82	)
	-1	The 2014 amounts include net foreign currency translation gain of $21 million attributable to noncontrolling interests.
	-2	As a result of our sale of our 49% equity interest in Nadro, foreign currency translation net losses of $44 million were reclassified from AOCI to other income, within our consolidated statement of operations. Such losses were previously considered in our impairment evaluation of the investment when we committed to a plan to sell the investment during the fourth quarter of 2013, and accordingly did not impact earnings for 2014.
	-3	Pre-tax amount was reclassified into cost of sales and operating expenses in the consolidated statements of operations. The related tax expense (benefit) was reclassified into income tax expense in the consolidated statements of operations.
	Accumulated Other Comprehensive Income (Loss)
	Information regarding changes in our accumulated other comprehensive income (loss) by component are as follows:
	(In millions)	Foreign Currency Translation Adjustments, Net of Tax			Unrealized Losses on Cash Flow Hedges,			Unrealized Net Loss and Other Components of Benefit Plans, Net of Tax			Total Accumulated Other Comprehensive Income (Loss)
					Net of Tax
	Balance at March 31, 2012	$	188		$	(5	)	$	(178	)	$	5
	Other comprehensive loss before reclassifications	(52		)	—			(18		)	(70		)
	Other comprehensive loss	(52		)	—			(18		)	(70		)
	Balance at March 31, 2013	$	136		$	(5	)	$	(196	)	$	(65	)
	Other comprehensive income (loss) before reclassifications	(12		)	(6		)	35			17
	Amounts reclassified to earnings	44			—			1			45
	Other comprehensive income (loss)	32			(6		)	36			62
	Balance at March 31, 2014	$	168		$	(11	)	$	(160	)	$	(3	)

Related_Party_Balances_and_Tra

Related Party Balances and Transactions	12 Months Ended
	Mar. 31, 2014
Related Party Transactions [Abstract]	'
Related Party Balances and Transactions	'
	Related Party Balances and Transactions
	In April 2012, we purchased the remaining ownership interest in our corporate headquarters building which was previously accounted for as an equity method investment. As a result, there was no annual rental expense paid in 2014 and 2013. We incurred $10 million in 2012 of annual rental expense paid to this equity-held investment.

Segments_of_Business

Segments of Business	12 Months Ended
	Mar. 31, 2014
Segment Reporting [Abstract]	'
Segments of Business	'
	Segments of Business
	We report our operations in two operating segments: McKesson Distribution Solutions and McKesson Technology Solutions. The factors for determining the reportable segments included the manner in which management evaluates the performance of the Company combined with the nature of the individual business activities. We evaluate the performance of our operating segments on a number of measures, including operating profit before interest expense, income taxes and results from discontinued operations.
	The McKesson Distribution Solutions segment distributes ethical and proprietary drugs and equipment and health and beauty care products throughout North America and internationally. This segment includes our International pharmaceutical distribution and services business which reflects the results of operations from our acquisition of Celesio in February 2014. This segment also provides specialty pharmaceutical solutions for biotech and pharmaceutical manufacturers, and practice management, technology, clinical support and business solutions to oncology and other specialty practices operating in the community setting. This segment also provides medical-surgical supply distribution, equipment, logistics and other services to healthcare providers through a network of distribution centers within the U.S. In addition, this segment sells financial, operational and clinical solutions for pharmacies (retail, hospital, alternate site) and provides consulting, outsourcing and other services. In September 2013, we sold our 49% interest in Nadro, S.A. de C.V. (“Nadro”), a pharmaceutical distributor in Mexico. Prior to the sale, financial results for Nadro were included in this segment.
	The McKesson Technology Solutions segment includes McKesson Health Solutions, which includes our InterQual® clinical criteria solution, claims payment solutions and network performance tools. This segment also delivers enterprise-wide clinical, patient care, financial, supply chain, strategic management software solutions, as well as connectivity, outsourcing and other services, including remote hosting and managed services, to healthcare organizations. This segment’s customers include hospitals, physicians, homecare providers, retail pharmacies and payers primarily from North America.
	Corporate includes expenses associated with Corporate functions and projects and the results of certain equity investments. Corporate expenses are allocated to the operating segments to the extent that these items can be directly attributable to the segment.
	Financial information relating to our reportable operating segments and reconciliations to the consolidated totals is as follows:
		Years Ended March 31,
	(In millions)	2014			2013			2012
	Revenues
	Distribution Solutions (1)
	North America pharmaceutical distribution and services	$	123,930		$	115,443		$	116,279
	International pharmaceutical distribution and services	4,848			—			—
	Medical-Surgical distribution & services	5,648			3,603			3,145
	Total Distribution Solutions	134,426			119,046			119,424
	Technology Solutions - products and services	3,183			3,023			2,897
	Total Revenues	$	137,609		$	122,069		$	122,321
	Operating profit
	Distribution Solutions	$	2,461		$	2,195		$	2,219
	Technology Solutions	387			308			338
	Total	2,848			2,503			2,557
	Corporate Expenses, Net	(449		)	(335		)	(413		)
	Interest expense	(303		)	(240		)	(251		)
	Income From Continuing Operations Before Income Taxes	$	2,096		$	1,928		$	1,893
	Depreciation and amortization (2)
	Distribution Solutions	$	448		$	265		$	224
	Technology Solutions	136			145			152
	Corporate	120			120			117
	Total	$	704		$	530		$	493
	Expenditures for long-lived assets (3)
	Distribution Solutions	$	180		$	163		$	175
	Technology Solutions	42			28			18
	Corporate	52			41			28
	Total	$	274		$	232		$	221
	Revenues, net by geographic area (4)
	United States	$	122,426		$	112,109		$	112,051
	Foreign	15,183			9,960			10,270
	Total	$	137,609		$	122,069		$	122,321
	-1	Revenues derived from services represent less than 2% of this segment’s total revenues.
	-2	Amounts primarily include amortization of acquired intangible assets purchased in connection with acquisitions, capitalized software held for sale and capitalized software for internal use.
	-3	Long-lived assets consist of property, plant and equipment.
	-4	Net revenues were attributed to geographic areas based on the customers’ shipment locations.
	Segment assets and property, plant and equipment, net by geographic areas were as follows:
		March 31,
	(In millions)	2014			2013
	Segment assets
	Distribution Solutions	$	42,758		$	27,307
	Technology Solutions	3,324			3,829
	Total	46,082			31,136
	Corporate
	Cash and cash equivalents	4,193			2,456
	Other	1,484			1,194
	Total	$	51,759		$	34,786
	Property, plant and equipment, net
	United States	$	1,246		$	1,205
	Foreign	976			116
	Total	$	2,222		$	1,321

Quarterly_Financial_Informatio

Quarterly Financial Information (Unaudited)	12 Months Ended
	Mar. 31, 2014
Quarterly Financial Information Disclosure [Abstract]	'
Quarterly Financial Information (Unaudited)	'
	Quarterly Financial Information (Unaudited)
	The quarters results of operations are not necessarily indicative of the results that may be expected for the entire year. Selected quarterly financial information for the last two years is as follows:
	(In millions, except per share amounts)	First		Second			Third			Fourth
		Quarter		Quarter			Quarter			Quarter
	Fiscal 2014
	Revenues	$	32,208	$	32,954		$	34,306		$	38,141
	Gross profit (1)	1,920		2,009			1,840			2,540
	Income after income taxes
	Continuing operations (1) (2)	$	420	$	416		$	156		$	362
	Discontinued operations (3)	4		(12		)	(92		)	4
	Net income	424		404			64			366
	Net loss attributable to noncontrolling interests (4)	—		—			—			5
	Net income attributable to McKesson	$	424	$	404		$	64		$	371
	Earnings (loss) per common share attributable
	to McKesson (5)
	Diluted
	Continuing operations	$	1.81	$	1.79		0.67			$	1.56
	Discontinued operations	0.02		(0.05		)	(0.39		)	0.02
	Total	$	1.83	$	1.74		$	0.28		$	1.58
	Basic
	Continuing operations	$	1.84	$	1.82		0.68			$	1.59
	Discontinued operations	0.02		(0.06		)	(0.40		)	0.02
	Total	$	1.86	$	1.76		$	0.28		$	1.61
	-1	Financial results for the second, third and fourth quarters of 2014 includes pre-tax charges in our Distribution Solutions segment related to our LIFO method of accounting for inventories of $44 million, $142 million and $125 million, which were recorded in cost of sales. Fourth quarter 2014 also includes a $50 million pre-tax charge to cost of sales within our Distribution Solutions segment representing the reversal of a step-up to fair value of Celesio’s inventory at the date of acquisition. Our after-tax portion of this charge (after allocation to noncontrolling interests), was $28 million.
	-2	Financial results for the third quarter of 2014 include an income tax charge of $122 million relating to a litigation with the Canadian Revenue Agency.
	-3	Financial results for the third quarter of 2014, include an $80 million of after-tax impairment charge related to our International Technology Business.
	-4	Primarily represents the noncontrolling shareholders’ portion of net loss from Celesio.
	-5	Certain computations may reflect rounding adjustments.
	(In millions, except per share amounts)	First		Second			Third			Fourth
		Quarter		Quarter			Quarter			Quarter
	Fiscal 2013
	Revenues	$	30,699	$	29,755		$	31,099		$	30,516
	Gross profit	1,561		1,683			1,645			1,959
	Income after income taxes
	Continuing operations (1) (2) (3)	$	379	$	399		$	306		$	263
	Discontinued operations	1		2			(8		)	(4		)
	Net income	380		401			298			259
	Net loss attributable to noncontrolling interests	—		—			—			—
	Net income attributable to McKesson	$	380	$	401		$	298		$	259
	Earnings per common share attributable
	to McKesson (4)
	Diluted
	Continued operations	$	1.58	$	1.66		$	1.27		$	1.11
	Discontinued operations	—		0.01			(0.03		)	(0.01		)
	Total	$	1.58	$	1.67		$	1.24		$	1.1
	Basic
	Continuing operations	$	1.61	$	1.69		$	1.3		$	1.13
	Discontinued operations	—		0.01			(0.03		)	(0.01		)
	Total	$	1.61	$	1.7		$	1.27		$	1.12
	-1	Financial results for the first quarter of 2013 include an $81 million pre-tax gain on business combination, which was recorded as a reduction to operating expenses within our Corporate segment.
	-2	Financial results for the third quarter of 2013 include a $40 million pre-tax charge for a legal dispute in our Canadian business which was recorded in operating expenses within our Distribution Solutions segment.
	-3	Financial results for the fourth quarter of 2013 include a pre-tax impairment charge for an equity investment of $191 million recorded in other income, net within our Distribution Solutions segment. Financial results for the fourth quarter of 2013 also include $46 million of pre-tax impairment charges recorded in our Technology Solutions segment of which $36 million was recorded in operating expenses and $10 million was recorded in cost of sales.
	-4	Certain computations may reflect rounding adjustments.

Supplementary_Consolidated_Fin

Supplementary Consolidated Financial Statement Schedule Valuation And Qualifying Accounts (Notes)	12 Months Ended
	Mar. 31, 2014
Valuation and Qualifying Accounts [Abstract]	'
Supplementary Consolidated Financial Statement Schedule Valuation and Qualifying Accounts	'
	SUPPLEMENTARY CONSOLIDATED FINANCIAL STATEMENT SCHEDULE
	VALUATION AND QUALIFYING ACCOUNTS
	For the Years Ended March 31, 2014, 2013 and 2012
	(In millions)
						Additions
	Description	Balance at Beginning of Year				Charged to Costs and Expenses				Charged to Other Accounts (3)				Deductions From Allowance Accounts (1)			Balance at End of
																	Year (2)
	Year Ended March 31, 2014
	Allowances for doubtful	$	121			$	38			$	(12	)		$	(34	)	$	113
	accounts
	Other allowances	15				—				11				(3		)	23
		$	136			$	38			$	(1	)		$	(37	)	$	136
	Year Ended March 31, 2013
	Allowances for doubtful	$	111			$	28			$	16			$	(34	)	$	121
	accounts
	Other allowances	14				4				1				(4		)	15
		$	125			$	32			$	17			$	(38	)	$	136
	Year Ended March 31, 2012
	Allowances for doubtful	$	124			$	30			$	—			$	(43	)	$	111
	accounts
	Other allowances	16				5				—				(7		)	14
		$	140			$	35			$	—			$	(50	)	$	125
				2014				2013				2012
	-1	Deductions:
		Written off		$	(39	)		$	(38	)		$	(44	)
		Credited to other accounts		2				—				(6		)
		Total		$	(37	)		$	(38	)		$	(50	)
	-2	Amounts shown as deductions from current and non-current receivables		$	136			$	136			$	125
	-3	Primarily represents reclassifications from other balance sheet accounts.

Significant_Accounting_Policie1

Significant Accounting Policies (Policy)	12 Months Ended
	Mar. 31, 2014
Accounting Policies [Abstract]	'
Nature of Operations	'
	Nature of Operations: McKesson Corporation (“McKesson,” the “Company,” the “Registrant” or “we” and other similar pronouns) delivers pharmaceuticals, medical supplies and healthcare information technology that make healthcare safer while reducing costs. We conduct our business through two operating segments, McKesson Distribution Solutions and McKesson Technology Solutions, as further described in Financial Note 25, “Segments of Business.”
Basis of Presentation	'
	Basis of Presentation: The consolidated financial statements and accompanying notes are prepared in accordance with U. S. generally accepted accounting principles (“GAAP”). The consolidated financial statements of McKesson include the financial statements of all wholly-owned subsidiaries and majority-owned or controlled companies. We also evaluate our ownership, contractual and other interests in entities to determine if they are variable interest entities (“VIEs”), if we have a variable interest in those entities and the nature and extent of those interests. These evaluations are highly complex and involve judgment and the use of estimates and assumptions based on available historical information and management’s judgment, among other factors. Based on our evaluations, if we determine we are the primary beneficiary of such VIEs we consolidate such entities into our financial statements. Refer to Financial Note 15, “Variable Interest Entities” for more information on these VIEs. Investments in business entities in which we do not have control, but have the ability to exercise significant influence over operating and financial policies, are accounted for using the equity method and our proportionate share of income or loss is recorded in other income, net. Equity investments in non-publicly traded entities are primarily accounted for using the cost method. Intercompany transactions and balances have been eliminated.
Fiscal Period	'
	Fiscal Period: The Company’s fiscal year begins on April 1 and ends on March 31. Unless otherwise noted, all references to a particular year shall mean the Company’s fiscal year.
Reclassifications	'
	Reclassifications: Certain prior year amounts have been reclassified to conform to the current year presentation.
Use of Estimates	'
	Use of Estimates: The preparation of financial statements in conformity with U.S. GAAP requires that we make estimates and assumptions that affect the reported amounts in the consolidated financial statements and accompanying notes. Actual amounts could differ from those estimated amounts.
Cash and Cash Equivalents	'
	Cash and Cash Equivalents: All highly liquid debt instruments purchased with original maturity of three months or less at the date of acquisition are included in cash and cash equivalents.
	Cash equivalents, which are available-for-sale, are carried at fair value. Cash equivalents are primarily invested in AAA rated prime and U.S. government money market funds denominated in U.S. dollars, AAA rated prime money market funds denominated in Euros, overnight repurchase agreements collateralized by U.S. Treasury bonds, Canadian government securities and/or securities that are guaranteed or sponsored by the U.S. government and an AAA rated prime money market fund denominated in British pound sterling.
	The remaining cash and cash equivalents are deposited with several financial institutions. Deposits at U.S. banks exceed the amount insured by the Federal Deposit Insurance Corporation. We mitigate the risk of our short-term investment portfolio by depositing funds with reputable financial institutions and monitoring risk profiles and investment strategies of money market funds. Within the Celesio operations, the majority of deposits are placed in Germany with only banks that are part of deposit protection programs.
Restricted Cash	'
	Restricted Cash: Cash that is subject to legal restrictions or is unavailable for general operating purposes is classified as restricted cash and is included within prepaid expenses and other in the consolidated balance sheets. At March 31, 2014 and 2013 restricted cash was not material.
Marketable Securities Available for Sale	'
	Marketable Securities Available-for-Sale: We carry our marketable securities, which are available-for-sale, at fair value and they are included in prepaid expenses and other in the consolidated balance sheets. The unrealized gains and losses, net of the related tax effect, computed in marking these securities to market have been reported within stockholders’ equity. At March 31, 2014 and 2013 marketable securities were not material.
	In determining whether an other-than-temporary decline in market value has occurred, we consider the duration that, and extent to which, the fair value of the investment is below its cost, the financial condition and future prospects of the issuer or underlying collateral of a security, and our intent and ability to retain the security in order to allow for an anticipated recovery in fair value. Other-than-temporary declines in fair value from amortized cost for available-for-sale equity securities that we intend to sell or would more likely than not be required to sell before the expected recovery of the amortized cost basis are charged to other income (expense) in the period in which the loss occurs.
Concentration of Credit Risk and Receivables	'
	Concentrations of Credit Risk and Receivables: Our trade receivables are subject to a concentration of credit risk with customers primarily in our Distribution Solutions segment. During 2014, sales to our ten largest customers accounted for approximately 48% of our total consolidated revenues. Sales to our largest customer, CVS Caremark Corporation ("CVS"), accounted for approximately 16% of our total consolidated revenues. At March 31, 2014, trade accounts receivable from our ten largest customers were approximately 32% of total trade accounts receivable. Accounts receivable from CVS were approximately 12% of total trade accounts receivable. As a result, our sales and credit concentration is significant. We also have agreements with group purchasing organizations (“GPOs”), each of which functions as a purchasing agent on behalf of member hospitals, pharmacies and other healthcare providers. The accounts receivables balances are with individual members of the GPOs. A default in payment, a material reduction in purchases from these or any other large customers, or the loss of a large customer or customer groups could have a material adverse impact on our financial condition, results of operations and liquidity. In addition, trade receivables are subject to a concentration of credit risk with customers in the institutional, retail and healthcare provider sectors, which can be affected by a downturn in the economy and changes in reimbursement policies. This credit risk is mitigated by the size and diversity of the customer base as well as its geographic dispersion. We estimate the receivables for which we do not expect full collection based on historical collection rates and ongoing evaluations of the creditworthiness of our customers. An allowance is recorded in our consolidated financial statements for these amounts.
Financing Receivables	'
	Financing Receivables: We assess and monitor credit risk associated with financing receivables, namely lease and notes receivables, through regular review of our collection experience in determining our allowance for loan losses. On an ongoing basis, we also evaluate credit quality of our financing receivables utilizing aging of receivables and write-offs, as well as considering existing economic conditions, to determine if an allowance is necessary. Financing receivables are derecognized if legal title to them has been transferred and all related risks and rewards incidental to ownership have passed to the buyer.  As of March 31, 2014 and 2013, financing receivables and the related allowance were not material to our consolidated financial statements.
Inventories	'
	Inventories: We report inventories at the lower of cost or market (“LCM”). Inventories for our Distribution Solutions segment consist of merchandise held for resale. For our Distribution Solutions segment, the majority of the cost of domestic inventories is determined using the last-in, first-out (“LIFO”) method. The majority of the cost of inventories held in foreign locations is based on weighted average purchase prices using the first-in, first-out method. Technology Solutions segment inventories consist of computer hardware with cost generally determined by the standard cost method, which approximates average cost. Rebates, cash discounts, and other incentives received from vendors are accounted for as a reduction in the cost of inventory and are recognized when the inventory is sold.
	The LIFO method was used to value approximately 67% and 80% of our inventories at March 31, 2014 and 2013. If we had used the FIFO method of inventory valuation, which approximates current replacement costs, inventories would have been approximately $431 million and $120 million higher than the amounts reported at March 31, 2014 and 2013, respectively. These amounts are equivalent to our LIFO reserves. Our LIFO valuation amount includes both pharmaceutical and non-pharmaceutical products. In 2014, 2013 and 2012, we recognized net LIFO expense of $311 million, $13 million and $11 million within our consolidated statements of operations. A LIFO expense is recognized when the net effect of price increases on branded pharmaceuticals and non-pharmaceutical products held in inventory exceeds the impact of price declines and shifts towards generic pharmaceuticals, including the effect of branded pharmaceutical products that have lost market exclusivity. A LIFO credit is recognized when the net effect of price declines and shifts towards generic pharmaceuticals exceeds the impact of price increases on branded pharmaceuticals and non-pharmaceutical products held in inventory.
	We believe that the average inventory costing method provides a reasonable estimation of the current cost of replacing inventory (i.e., “market”). As such, our LIFO inventory is valued at the lower of LIFO or market. Primarily due to historical net deflation in our pharmaceutical inventories, pharmaceutical inventories at LIFO were $60 million higher than market as of March 31, 2013. As a result, we recorded a LCM credit of $60 million and $16 million in 2014 and 2013 within our consolidated statements of operations to adjust our LIFO inventories to market.
Shipping and Handling Costs	'
	Shipping and Handling Costs: We include costs to warehouse, pick, pack and deliver inventory to our customers in selling, distribution and administrative expenses.
Property, Plant and Equipment	'
	Property, Plant and Equipment: We state our property, plant and equipment at cost and depreciate them under the straight-line method at rates designed to distribute the cost of properties over estimated service lives ranging from one to thirty years.
Goodwill	'
	Goodwill: Goodwill is tested for impairment on an annual basis in the fourth quarter or more frequently if indicators for potential impairment exist. Impairment testing is conducted at the reporting unit level, which is generally defined as a component — one level below our Distribution Solutions and Technology Solutions operating segments, for which discrete financial information is available and segment management regularly reviews the operating results of that unit. Components that have essentially similar operations, products, services, customers and operating margins are aggregated as a single reporting unit.
	The first step in goodwill testing requires us to compare the estimated fair value of a reporting unit to its carrying value. This step may be performed utilizing either a qualitative or quantitative assessment. If the carrying value of the reporting unit is lower than its estimated fair value, no further evaluation is necessary. If the carrying value of the reporting unit is higher than its estimated fair value, the second step must be performed to measure the amount of impairment loss. Under the second step, the implied fair value of goodwill is calculated in a hypothetical analysis by subtracting the fair value of all assets and liabilities of the reporting unit, including any unrecognized intangible assets, from the fair value of the reporting unit calculated in the first step of the impairment test. If the carrying value of goodwill for the reporting unit exceeds the implied fair value of goodwill, an impairment charge is recorded for that excess.
	To estimate the fair value of our reporting units, we use a combination of the market approach and the income approach. Under the market approach, we estimate fair value by comparing the business to similar businesses or guideline companies whose securities are actively traded in public markets. Under the income approach, we use a discounted cash flow model in which cash flows anticipated over several periods, plus a terminal value at the end of that time horizon, are discounted to their present value using an appropriate expected rate of return. The discount rate used for cash flows reflects capital market conditions and the specific risks associated with the business. In addition, we compare the aggregate of the reporting units’ fair value to the Company’s market capitalization as a further corroboration of the fair values. The testing requires a complex series of assumptions and judgment by management in projecting future operating results, selecting guideline companies for comparisons and assessing risks. The use of alternative assumptions and estimates could affect the fair values and change the impairment determinations.
Intangible Assets	'
	Intangible Assets: Currently all of our intangible assets are subject to amortization and are amortized based on the pattern of their economic consumption or on a straight-line basis over their estimated useful lives, ranging from one to thirty-eight years. We review intangible assets for impairment whenever events or changes in circumstances indicate that the carrying value of the assets may not be recoverable. Determination of recoverability is based on the lowest level of identifiable estimated future undiscounted cash flows resulting from use of the asset and its eventual disposition. Measurement of any impairment loss is based on the excess of the carrying value of the asset over its fair market value.
Capitalized Software Held for Sale	'
	Capitalized Software Held for Sale: Development costs for software held for sale, which primarily pertain to our Technology Solutions segment, are capitalized once a project has reached the point of technological feasibility. Completed projects are amortized after reaching the point of general availability using the straight-line method based on an estimated useful life of approximately three years. At each balance sheet date, or earlier if an indicator of an impairment exists, we evaluate the recoverability of unamortized capitalized software costs based on estimated future undiscounted revenues net of estimated related costs over the remaining amortization period.
Capitalized Software Held for Internal Use	'
	Capitalized Software Held for Internal Use: We capitalize costs of software held for internal use during the application development stage of a project and amortize those costs over their estimated useful lives ranging from one to ten years. As of March 31, 2014 and 2013, capitalized software held for internal use was $514 million and $465 million, net of accumulated amortization of $1,004 million and $1,011 million, and was included in other assets in the consolidated balance sheets.
Insurance Programs	'
	Insurance Programs: Under our insurance programs, we seek to obtain coverage for catastrophic exposures as well as those risks required to be insured by law or contract. It is our policy to retain a significant portion of certain losses primarily related to workers’ compensation and comprehensive general, product and vehicle liability. Provisions for losses expected under these programs are recorded based upon our estimate of the aggregate liability for claims incurred as well as for claims incurred but not yet reported. Such estimates utilize certain actuarial assumptions followed in the insurance industry.
Revenue Recognition	'
	Revenue Recognition:
	Distribution Solutions
	Revenues for our Distribution Solutions segment are recognized when product is delivered and title passes to the customer or when services have been rendered and there are no further obligations to the customer.
	Revenues are recorded net of sales returns, allowances, rebates and other incentives. Our sales return policy generally allows customers to return products only if they can be resold for value or returned to suppliers for full credit. Sales returns are accrued based on estimates at the time of sale to the customer. Sales returns from customers were approximately $1.9 billion in 2014, $1.9 billion in 2013 and $1.6 billion in 2012. Taxes collected from customers and remitted to governmental authorities are presented on a net basis; that is, they are excluded from revenues.
	Revenues for our Distribution Solutions segment include large volume sales of pharmaceuticals primarily to a limited number of large customers who warehouse their own product. We order bulk product from the manufacturer, receive and process the product primarily through our central distribution facility and deliver the bulk product (generally in the same form as received from the manufacturer) directly to our customers’ warehouses. We also record revenues for direct store deliveries from most of these same customers. Direct store deliveries are shipments from the manufacturer to our customers of a limited category of products that require special handling. We assume the primary liability to the manufacturer for these products.
	Revenues are recorded gross when we are the primary party obligated in the transaction, take title to and possession of the inventory, are subject to inventory risk, have latitude in establishing prices, assume the risk of loss for collection from customers as well as delivery or return of the product, are responsible for fulfillment and other customer service requirements, or the transactions have several but not all of these indicators.
	Our Distribution Solutions segment also engages in multiple-element arrangements, which may contain a combination of various products and services. Revenue from a multiple element arrangement is allocated to the separate elements based on their relative selling price and recognized in accordance with the revenue recognition criteria applicable to each element. Relative selling price is determined based on vendor-specific objective evidence (“VSOE”) of selling price, if available, third-party evidence (“TPE”), if VSOE of selling price is not available, or estimated selling price (“ESP”), if neither VSOE of selling price nor TPE is available.
	Technology Solutions
	Revenues for our Technology Solutions segment are generated primarily by licensing software and software systems (consisting of software, hardware and maintenance support), and providing claims processing, outsourcing and professional services. Software and hardware are included in product revenue, while maintenance support among other services are included in service revenue. Revenue for this segment is recognized as follows:
	Software systems are marketed under information systems agreements as well as service agreements. Perpetual software arrangements are recognized at the time of delivery or under the percentage-of-completion method if the arrangements require significant production, modification or customization of the software. Contracts accounted for under the percentage-of-completion method are generally measured based on the ratio of labor hours incurred to date to total estimated labor hours to be incurred. Changes in estimates to complete and revisions in overall profit estimates on these contracts are charged to earnings in the period in which they are determined. We accrue for contract losses if and when the current estimate of total contract costs exceeds total contract revenue.
	Revenue from time-based software license agreements is recognized ratably over the term of the agreement. Software implementation fees are recognized as the work is performed or under the percentage-of-completion method. Maintenance and support agreements are marketed under annual or multi-year agreements and are recognized ratably over the period covered by the agreements. Hardware revenues are generally recognized upon delivery.
	Subscription, content and transaction processing fees are generally marketed under annual and multi-year agreements and are recognized ratably over the contracted terms beginning on the service start date for fixed fee arrangements and recognized as transactions are performed beginning on the service start date for per-transaction fee arrangements. Remote processing service fees are recognized monthly as the service is performed. Outsourcing service revenues are recognized as the service is performed.
	We also offer certain products on an application service provider basis, making our software functionality available on a remote hosting basis from our data centers. The data centers provide system and administrative support, as well as hosting services. Revenue on products sold on an application service provider basis is recognized on a monthly basis over the term of the contract beginning on the service start date of products hosted.
	This segment engages in multiple-element arrangements, which may contain any combination of software, hardware, implementation or consulting services, or maintenance services. For multiple element arrangements that do not include software, revenue is allocated to the separate elements based on their relative selling price and recognized in accordance with the revenue recognition criteria applicable to each element. Relative selling price is determined based on VSOE of selling price if available, TPE, if VSOE of selling price is not available, or ESP if neither VSOE of selling price nor TPE is available. For multiple-element arrangements accounted for in accordance with specific software accounting guidance when some elements are delivered prior to others in an arrangement and VSOE of fair value exists for the undelivered elements, revenue for the delivered elements is recognized upon delivery of such items. The segment establishes VSOE for hardware and implementation and consulting services based on the price charged when sold separately, and for maintenance services, based on renewal rates offered to customers. Revenue for the software element is recognized under the residual method only when fair value has been established for all of the undelivered elements in an arrangement. If fair value cannot be established for any undelivered element, all of the arrangement’s revenue is deferred until the delivery of the last element or until the fair value of the undelivered element is determinable. For multiple-element arrangements with both software elements and nonsoftware elements, arrangement consideration is allocated between the software elements as a whole and nonsoftware elements.  The segment then further allocates consideration to the individual elements within the software group, and revenue is recognized for all elements under the applicable accounting guidance and our policies described above.
Supplier Incentives	'
	Supplier Incentives: Fees for service and other incentives received from suppliers, relating to the purchase or distribution of inventory, are generally reported as a reduction to cost of goods sold. We consider these fees and other incentives to represent product discounts and as a result, the amounts are recorded as a reduction of product cost and are recognized through cost of goods sold upon the sale of the related inventory.
Supplier Reserves	'
	Supplier Reserves: We establish reserves against amounts due from suppliers relating to various price and rebate incentives, including deductions or billings taken against payments otherwise due to them. These reserve estimates are established based on judgment after considering the status of current outstanding claims, historical experience with the suppliers, the specific incentive programs and any other pertinent information available. We evaluate the amounts due from suppliers on a continual basis and adjust the reserve estimates when appropriate based on changes in factual circumstances. As of March 31, 2014 and 2013 supplier reserves were $181 million and $164 million. The ultimate outcome of any outstanding claims may be different than our estimate. All of the supplier reserves at March 31, 2014 and 2013 pertain to our Distribution Solutions segment.
Income Taxes	'
	Income Taxes: We account for income taxes under the asset and liability method, which requires the recognition of deferred tax assets and liabilities for the expected future tax consequences of events that have been included in the financial statements. Under this method, deferred tax assets and liabilities are determined based on the difference between the financial statements and the tax basis of assets and liabilities using enacted tax rates in effect for the year in which the differences are expected to reverse. Tax benefits from uncertain tax positions are recognized when it is more likely than not that the position will be sustained upon examination, including resolutions of any related appeals or litigation processes, based on the technical merits. The amount recognized is measured as the largest amount of tax benefit that is greater than 50 percent likely of being realized upon effective settlements. Deferred taxes are not provided on undistributed earnings of our foreign operations that are considered to be permanently reinvested.
Foreign Currency Translation	'
	Foreign Currency Translation: Our international subsidiaries generally consider their local currency to be their functional currency. Assets and liabilities of these international subsidiaries are translated into U.S. dollars at year-end exchange rates and revenues and expenses are translated at average exchange rates during the year. Currency translation adjustments for the year are included in other comprehensive income or loss in the statements of consolidated comprehensive income, and the cumulative effect is included in the stockholders’ equity section of the consolidated balance sheets. When we sell all or substantially all of an international entity, the related share of the cumulative currency translation adjustment is removed from stockholders’ equity and is included in the gain or loss on sale in the consolidated statements of operations. Realized gains and losses from currency exchange transactions are recorded in operating expenses in the consolidated statements of operations and were not material to our consolidated results of operations in 2014, 2013 or 2012.
Derivative Financial Instruments	'
	Derivative Financial Instruments: Derivative financial instruments are used principally in the management of foreign currency and interest rate exposures and are recorded on the consolidated balance sheets at fair value. If a derivative is designated as a fair value hedge, the changes in the fair value of the derivative and of the hedged item attributable to the hedged risk are recognized as a charge or credit to earnings. If the derivative is designated as a cash flow hedge, the effective portions of changes in the fair value of the derivative are included in other comprehensive income or loss in the statements of consolidated comprehensive income, and the cumulative effect is included in the stockholders’ equity section of the consolidated balance sheets. The cumulative changes in fair value are reclassed to the consolidated statements of operations when the hedged item affects earnings. We periodically evaluate hedge effectiveness, and ineffective portions of changes in the fair value of cash flow hedges are recognized as a charge or credit to earnings. Derivative instruments not designated as hedges are marked-to-market at the end of each accounting period with the change included in earnings.
Comprehensive Income, Policy [Policy Text Block]	'
	Comprehensive Income: Comprehensive income consists of two components, net income and other comprehensive income. Other comprehensive income refers to revenue, expenses, and gains and losses that under GAAP are recorded as an element of shareholders’ equity but are excluded from net income. Our other comprehensive income consists of foreign currency translation adjustments from those subsidiaries where the local currency is the functional currency, unrealized gains and losses on cash flow hedges, as well as unrealized gains and losses on retirement-related benefit plans.
Consolidation, Subsidiaries or Other Investments, Consolidated Entities, Policy [Policy Text Block]	'
	Noncontrolling Interests: Noncontrolling interests primarily represent the portion of Celesio’s profit or loss, net assets and comprehensive income that is not allocable to McKesson Corporation.
Share-Based Compensation	'
	Share-Based Compensation: We account for all share-based compensation transactions using a fair-value based measurement method. The share-based compensation expense, for the portion of the awards that is ultimately expected to vest, is recognized on a straight-line basis over the requisite service period. The compensation expense recognized has been classified in the consolidated statements of operations or capitalized on the consolidated balance sheets in the same manner as cash compensation paid to our employees.
Loss Contingencies	'
	Loss Contingencies: We are subject to various claims, other pending and potential legal actions for damages, investigations relating to governmental laws and regulations and other matters arising out of the normal conduct of our business. When a loss is considered probable and reasonably estimable, we record a liability in the amount of our best estimate for the ultimate loss. However, the likelihood of a loss with respect to a particular contingency is often difficult to predict and determining a meaningful estimate of the loss or a range of loss may not be practicable based on the information available and the potential effect of future events and decisions by third parties that will determine the ultimate resolution of the contingency. Moreover, it is not uncommon for such matters to be resolved over many years, during which time relevant developments and new information must be reevaluated at least quarterly to determine both the likelihood of potential loss and whether it is possible to reasonably estimate a range of possible loss. When a loss is probable but a reasonable estimate cannot be made, disclosure of the proceeding is provided.
	Disclosure also is provided when it is reasonably possible that a loss will be incurred or when it is reasonably possible that the amount of a loss will exceed the recorded provision. We review all contingencies at least quarterly to determine whether the likelihood of loss has changed and to assess whether a reasonable estimate of the loss or range of the loss can be made. As discussed above, development of a meaningful estimate of loss or a range of potential loss is complex when the outcome is directly dependent on negotiations with or decisions by third parties, such as regulatory agencies, the court system and other interested parties. Such factors bear directly on whether it is possible to reasonably estimate a range of potential loss and boundaries of high and low estimate.
Business Combinations	'
	Business Combinations: We account for acquired businesses using the acquisition method of accounting, which requires that once control is obtained of a business, 100% of the assets acquired and liabilities assumed, including amounts attributed to noncontrolling interests, be recorded at the date of acquisition at their respective fair values. Any excess of the purchase price over the estimated fair values of the net assets acquired is recorded as goodwill. Acquisition-related expenses and related restructuring costs are expensed as incurred.
	Several valuation methods may be used to determine the fair value of assets acquired and liabilities assumed.  For intangible assets, we typically use the income method.  This method starts with a forecast of all of the expected future net cash flows for each asset.  These cash flows are then adjusted to present value by applying an appropriate discount rate that reflects the risk factors associated with the cash flow streams.  Some of the more significant estimates and assumptions inherent in the income method or other methods include the amount and timing of projected future cash flows, the discount rate selected to measure the risks inherent in the future cash flows and the assessment of the asset’s life cycle and the competitive trends impacting the asset, including consideration of any technical, legal, regulatory, or economic barriers to entry.  Determining the useful life of an intangible asset also requires judgment as different types of intangible assets will have different useful lives and certain assets may even be considered to have indefinite useful lives.
Recently Adopted Accounting Pronouncements	'
	Recently Adopted Accounting Pronouncements
	Comprehensive Income: In the first quarter of 2014, we adopted disclosure guidance related to the reporting of amounts reclassified out of Accumulated Other Comprehensive Income (“AOCI”). The guidance requires disclosure of amounts reclassified out of AOCI by component. In addition, an entity is required to present either on the face of the statement of operations or in the notes, significant amounts reclassified out of AOCI by the respective line items of net income but only if the amount reclassified is required to be reclassified to net income in its entirety in the same reporting period. For amounts not reclassified in their entirety to net income, an entity is required to cross-reference to other disclosures that provide additional detail about those amounts. This guidance did not have a material effect on our consolidated financial statements.
	Balance Sheet Offsetting: In the first quarter of 2014, we adopted disclosure guidance related to the offsetting of assets and liabilities. The guidance requires an entity to disclose information about offsetting assets and liabilities for derivatives, repurchase agreements and reverse purchase agreements, and securities borrowing and securities lending transactions that are either offset in accordance with specific GAAP criteria or subject to a master netting arrangement or similar agreement. The amended guidance did not have a material effect on our consolidated financial statements.
Recently Issued Accounting Pronouncements Not Yet Adopted	'
	Recently Issued Accounting Pronouncements Not Yet Adopted
	Cumulative Translation Adjustments: In March 2013, amended guidance was issued for parent’s accounting for the cumulative translation adjustment upon derecognition of certain subsidiaries or group of assets within a foreign entity or of an investment in a foreign entity.  The amended guidance requires the release of any cumulative translation adjustment into net income only upon complete or substantially complete liquidation of a controlling interest in a subsidiary or a group of assets within a foreign entity.  Also, it requires the release of all or a pro rata portion of the cumulative translation adjustment to net income in case of sale of an equity method investment that is a foreign entity.  The amended guidance is applicable to us effective first quarter of fiscal 2015. Early adoption is permitted.  We are currently evaluating the impact of this amended guidance on our consolidated financial statements
Discontinued Operations, Policy [Policy Text Block]	'
	Discontinued Operations: In April 2014, amended guidance was issued for reporting of discontinued operations and disclosures of disposals of components.  The amended guidance raises the threshold for disposals to qualify as discontinued operations and permits significant continuing involvement and continuing cash flows with the discontinued operation.  In addition, the amended guidance requires additional disclosures for discontinued operations and new disclosures for individually material disposal transactions that do not meet the definition of a discontinued operation.  The amended guidance is effective for us prospectively commencing in the first quarter of 2016.  Early adoption is permitted. We are currently evaluating the impact of this amended guidance on our consolidated financial statements.

Business_Combinations_Tables

Business Combinations (Tables)	12 Months Ended
	Mar. 31, 2014
Business Acquisition [Line Items]	'
Business Acquisition, Integration, Restructuring and Other Related Costs [Text Block]	'
	We incurred the following acquisition expenses and related adjustments:
		Years Ended March 31,
	(In millions)	2014			2013			2012
	Cost of Sales	$	3		$	—		$	—
	Operating Expenses
	Transaction closing expenses	39			16			3
	Restructuring, severance and relocation	43			30			3
	Other integration related expenses	73			25			20
	Gain on business combination	—			(81		)	—
	Total	155			(10		)	26
	Other Income, Net	14			—			—
	Interest Expense - bridge loan fees	46			11			—
	Total Acquisition Expenses and Related Adjustments	$	218		$	1		$	26
Business Acquisition, Integration, Restructuring and Other Related Costs-By Segment [Table Text Block]	'
	The acquisition expenses and related adjustments by segment is as follows:
		Years Ended March 31,
	(In millions)	2014			2013			2012
	Cost of Sales - Technology Solutions	$	3		$	—		$	—
	Operating Expenses
	Distribution Solutions	119			47			24
	Technology Solutions	15			7			1
	Corporate	21			(64		)	1
	Total	155			(10		)	26
	Corporate - Other Income, Net	14			—			—
	Corporate - Interest Expense	46			11			—
	Total Acquisition Expenses and Related Adjustments	$	218		$	1		$	26
Celesio [Member]	'
Business Acquisition [Line Items]	'
Business Acquisition, Pro Forma Information [Table Text Block]	'
	The following table provides pro forma results of operations for the years ended March 31, 2014 and March 31, 2013, as if Celesio had been acquired as of April 1, 2012. The pro forma results include the effect of preliminary purchase accounting adjustments such as the estimated changes in depreciation and amortization expense on the acquired tangible and intangible assets, financing costs, and related income tax expense. These adjustments are subject to change within the measurement period as our fair values assessments are finalized. The pro forma results do not reflect any material cost of integration activities or benefits that may result from synergies that may be derived from any integration activities. Accordingly, such amounts are not necessarily indicative of the results if the acquisition had occurred on the date indicated or which may occur in the future.
		Unaudited pro forma for the
		Years Ended March 31,
	(In millions)	2014			2013
	Net revenues	$	161,483		$	150,395
	Net income from continuing operations attributable to McKesson (1)	$	1,493		$	1,202
Schedule of Business Acquisitions, by Acquisition [Table Text Block]	'
	The fair value of the noncontrolling interests on the date of acquisition of $1,500 million was made up of the following components:
	(In millions)	Amounts
		Recognized as of
		Acquisition Date
		(Provisional)
	Fair value of Celesio common shares not acquired by McKesson	$	1,412
	Fair value of Celesio’s previously existing noncontrolling interests	88
	Total	$	1,500
	The following table summarizes the preliminary recording of the fair values of the assets acquired and liabilities assumed as of the acquisition date. Due to the recent timing of the acquisition, these amounts are subject to change within the measurement period as our fair value assessments are finalized.
	(In millions)	Amounts
		Recognized as of
		Acquisition Date
		(Provisional)
	Receivables	$	3,425
	Other current assets, net of cash and cash equivalents acquired	2,413
	Goodwill	3,570
	Intangible assets	3,018
	Other long-term assets	1,272
	Current liabilities	(4,096		)
	Short-term borrowings and current portion of long-term debt	(1,990		)
	Long-term debt	(322		)
	Other long-term liabilities	(1,293		)
	Fair value of net assets, less cash and cash equivalents	5,997
	Less: Noncontrolling Interests	(1,500		)
	Net assets acquired, net of cash and cash equivalents	$	4,497

Discontinued_Operations_Discon

Discontinued Operations Discontinued Operations (Tables)	12 Months Ended
	Mar. 31, 2014
Discontinued Operations and Disposal Groups [Abstract]	'
Schedule of Disposal Groups, Including Discontinued Operations, Income Statement, Balance Sheet and Additional Disclosures [Table Text Block]	'
		Years Ended March 31,
	(In millions)	2014			2013			2012
	Revenues	$	421		$	386		$	413
	Income (loss) from discontinued operations	$	(102	)	$	(9	)	$	26
	Loss on sale	(5		)	—			—
	Income (loss) from discontinued operations before income tax	(107		)	(9		)	26
	Income tax (expense) benefit	11			—			(2		)
	Income (loss) from discontinued operations, net of tax	$	(96	)	$	(9	)	$	24

ShareBased_Compensation_Tables

Share-Based Compensation (Tables)	12 Months Ended
	Mar. 31, 2014
Share-based Compensation [Abstract]	'
Components Of Share-Based Compensation Expense And Related Tax Benefits	'
		Years Ended March 31,
	(In millions)	2014				2013				2012
	RSUs (1)	$	88			$	109			$	97
	PeRSUs (2)	38				23				24
	Stock options	22				24				23
	Employee stock purchase plan	12				11				10
	Share-based compensation expense	160				167				154
	Tax benefit for share-based compensation expense (3)	(55		)		(59		)		(55		)
	Share-based compensation expense, net of tax	$	105			$	108			$	99
	-1	This expense was primarily the result of PeRSUs awarded in prior years, which converted to RSUs due to the attainment of goals during the applicable years’ performance period.
	-2	Represents estimated compensation expense for PeRSUs that are conditional upon attaining performance objectives during the current year’s performance period.
	-3	Income tax benefit is computed using the tax rates of applicable tax jurisdictions. Additionally, a portion of pre-tax compensation expense is not tax-deductible.
Schedule Of Weighted-Average Assumptions Used To Estimate The Fair Value Of Employee Stock Options	'
	Weighted-average assumptions used to estimate the fair value of employee stock options were as follows:
		Years Ended March 31,
		2014		2013		2012
	Expected stock price volatility	22%		27%		27%
	Expected dividend yield	0.70%		0.90%		1.00%
	Risk-free interest rate	0.70%		0.80%		2.10%
	Expected life (in years)	4		5		5
Summary Of Options Outstanding	'
	The following is a summary of stock options outstanding at March 31, 2014:
									Options Outstanding						Options Exercisable
	Range of Exercise								Number of		Weighted-		Weighted-		Number of	Weighted-
	Prices								Options		Average		Average		Options	Average
									Outstanding		Remaining		Exercise Price		Exercisable at	Exercise Price
									at Year End		Contractual				Year End
									(In millions)		Life (Years)				(In millions)
	$	35.53		–	$	69			3		2		$	55.7	2	$	53.76
	69.01			–	169.44				3		5		96.35		1	84.81
									6						3
Stock Option Activity	'
	The following table summarizes stock option activity during 2014:
	(In millions, except per share data)	Shares		Weighted-				Weighted-		Aggregate
				Average				Average		Intrinsic
				Exercise				Remaining		Value (2)
				Price				Contractual
								Term (Years)
	Outstanding, March 31, 2013	7		$	65.79			4		$	260
	Granted	1		120.79
	Exercised	-2		56.74
	Outstanding, March 31, 2014	6		$	78.07			4		$	473
	Vested and expected to vest (1)	5		$	77.27			4		$	472
	Vested and exercisable, March 31, 2014	3		61.07				3		281
	-1	The number of options expected to vest takes into account an estimate of expected forfeitures.
	-2	The intrinsic value is calculated as the difference between the period-end market price of the Company’s common stock and the exercise price of “in-the-money” options.
Data Related To Stock Option Activity	'
	The following table provides data related to stock option activity:
		Years Ended March 31,
	(In millions, except per share data)	2014				2013				2012
	Weighted-average grant date fair value per stock option	$	21.45			$	19.63			$	20.32
	Aggregate intrinsic value on exercise	$	144			$	107			$	108
	Cash received upon exercise	$	111			$	106			$	113
	Tax benefits realized related to exercise	$	55			$	41			$	40
	Total fair value of stock options vested	$	24			$	24			$	23
	Total compensation cost, net of estimated forfeitures, related to unvested stock options not yet recognized, pre-tax	$	29			$	37			$	40
	Weighted-average period in years over which stock option compensation cost is expected to be recognized	1				1				1
Data Related To RSU Activity	'
	The following table provides data related to RSU activity:
		Years Ended March 31,
	(In millions)	2014				2013				2012
	Total fair value of shares vested	$	184			$	66			$	44
	Total compensation cost, net of estimated forfeitures, related to nonvested RSU awards not yet recognized, pre-tax	$	115			$	128			$	143
	Weighted-average period in years over which RSU cost is expected to be recognized	2				2				3
	The following table summarizes RSU activity during 2014:
	(In millions, except per share data)	Shares		Weighted-
				Average
				Grant Date Fair
				Value Per Share
	Nonvested, March 31, 2013	6		$	76.2
	Granted	1		120.63
	Vested	-3		67.32
	Nonvested, March 31, 2014	4		$	93.25

Other_Income_Expense_Net_Table

Other Income (Expense), Net (Tables)	12 Months Ended
	Mar. 31, 2014
Other Nonoperating Income (Expense) [Abstract]	'
Other Income (Expense), Net	'
		Years Ended March 31,
	(In millions)	2014			2013		2012
	Interest income	$	23		$	22	$	19
	Equity in earnings (loss), net (1)	(3		)	3		9
	Other, net	12			9		(8		)
	Total	$	32		$	34	$	20
	-1	Primarily recorded within our Distribution Solutions segment.

Income_Taxes_Tables

Income Taxes (Tables)	12 Months Ended
	Mar. 31, 2014
Income Tax Disclosure [Abstract]	'
Income before Income Taxes From Continuing Operations	'
		Years Ended March 31,
	(In millions)	2014			2013			2012
	Income from continuing operations before income taxes
	U.S.	$	1,554		$	1,562		$	1,293
	Foreign	542			366			600
	Total income from continuing operations before income taxes	$	2,096		$	1,928		$	1,893
Components of Provision For Income Taxes Related to Continuing Operations	'
		Years Ended March 31,
	(In millions)	2014			2013			2012
	Current
	Federal	$	484		$	(84	)	$	265
	State	64			14			51
	Foreign	178			40			28
	Total current	726			(30		)	344
	Deferred
	Federal	24			538			132
	State	10			80			29
	Foreign	(18		)	(7		)	9
	Total deferred	16			611			170
	Income tax expense	$	742		$	581		$	514
Reconciliation Between Effective Tax Rate on Income From Continuing Operations and Statutory Tax Rate	'
		Years Ended March 31,
	(In millions)	2014			2013			2012
	Income tax expense at federal statutory rate	$	734		$	670		$	670
	State income taxes net of federal tax benefit	57			58			56
	Foreign income taxed at various rates	(166		)	(136		)	(174		)
	Canadian litigation	122			—			—
	Unrecognized tax benefits and settlements	(6		)	1			(18		)
	Tax credits	(6		)	(13		)	(13		)
	Other, net	7			1			(7		)
	Income tax expense	$	742		$	581		$	514
Components of Deferred Tax Assets and Liabilities	'
		March 31,
	(In millions)	2014			2013
	Assets
	Receivable allowances	$	106		$	84
	Deferred revenue	136			106
	Compensation and benefit related accruals	641			553
	Net operating loss and credit carryforwards	430			341
	Other	289			281
	Subtotal	1,602			1,365
	Less: valuation allowance	(270		)	(118		)
	Total assets	1,332			1,247
	Liabilities
	Inventory valuation and other assets	(2,163		)	(2,089		)
	Fixed assets and systems development costs	(321		)	(267		)
	Intangibles	(1,531		)	(734		)
	Other	(118		)	(24		)
	Total liabilities	(4,133		)	(3,114		)
	Net deferred tax liability	$	(2,801	)	$	(1,867	)
	Current net deferred tax asset	$	51		$	16
	Current net deferred tax liability	(1,588		)	(1,626		)
	Long-term deferred tax asset	19			21
	Long-term deferred tax liability	(1,283		)	(278		)
	Net deferred tax liability	$	(2,801	)	$	(1,867	)
Gross Unrecognized Tax Benefits	'
		Years Ended March 31,
	(In millions)	2014			2013			2012
	Unrecognized tax benefits at beginning of period	$	560		$	595		$	635
	Additions based on tax positions related to prior years	106			46			11
	Reductions based on tax positions related to prior years	(31		)	(108		)	(72		)
	Additions based on tax positions related to current year	23			31			37
	Reductions based on settlements	(4		)	(2		)	(1		)
	Reductions based on the lapse of the applicable statutes of limitations	(7		)	(2		)	(15		)
	Unrecognized tax benefits at end of period	$	647		$	560		$	595

Earnings_Per_Common_Share_Tabl

Earnings Per Common Share (Tables)	12 Months Ended
	Mar. 31, 2014
Earnings Per Share [Abstract]	'
Basic and Diluted Earnings per Common Share	'
		Years Ended March 31,
	(In millions, except per share amounts)	2014			2013			2012
	Income from continuing operations	$	1,354		$	1,347		$	1,379
	Net loss attributable to noncontrolling interests	5			—			—
	Income from continuing operations attributable to McKesson	1,359			1,347			1,379
	Income (loss) from discontinued operations, net of tax	(96		)	(9		)	24
	Net income attributable to McKesson	$	1,263		$	1,338		$	1,403
	Weighted average common shares outstanding:
	Basic	229			235			246
	Effect of dilutive securities:
	Options to purchase common stock	1			1			2
	Restricted stock units	3			3			3
	Diluted	233			239			251
	Earnings (loss) per common share attributable to McKesson: (1)
	Diluted
	Continuing operations	$	5.83		$	5.62		$	5.49
	Discontinued operations	(0.42		)	(0.03		)	0.1
	Total	$	5.41		$	5.59		$	5.59
	Basic
	Continuing operations	$	5.93		$	5.74		$	5.6
	Discontinued operations	(0.42		)	(0.03		)	0.1
	Total	$	5.51		$	5.71		$	5.7
	-1	Certain computations may reflect rounding adjustments.

Receivables_Net_Tables

Receivables, Net (Tables)	12 Months Ended
	Mar. 31, 2014
Receivables, Net, Current [Abstract]	'
Schedule of Accounts Receivable	'
		March 31,
	(In millions)	2014			2013
	Customer accounts	$	12,543		$	8,683
	Other	1,780			1,423
	Total	14,323			10,106
	Allowances	(130		)	(131		)
	Net	$	14,193		$	9,975

Property_Plant_and_Equipment_N1

Property, Plant and Equipment, Net (Tables)	12 Months Ended
	Mar. 31, 2014
Property, Plant and Equipment, Net [Abstract]	'
Schedule of Property, Plant and Equipment, Net	'
		March 31,
	(In millions)	2014			2013
	Land	$	221		$	129
	Building, machinery, equipment and other	3,180			2,400
	Total property, plant and equipment	3,401			2,529
	Accumulated depreciation	(1,179		)	(1,208		)
	Property, plant and equipment, net	$	2,222		$	1,321

Goodwill_and_Intangible_Assets1

Goodwill and Intangible Assets, Net (Tables)	12 Months Ended
	Mar. 31, 2014
Goodwill and Intangible Assets Disclosure [Abstract]	'
Changes in the Carrying Amount of Goodwill	'
	(In millions)	Distribution				Technology				Total
		Solutions				Solutions
	Balance, March 31, 2012	$	3,190			$	1,842			$	5,032
	Goodwill acquired	1,228				193				1,421
	Impairment	—				(36		)		(36		)
	Acquisition accounting and other adjustments	6				(1		)		5
	Foreign currency translation adjustments	(11		)		(6		)		(17		)
	Balance, March 31, 2013	$	4,413			$	1,992			$	6,405
	Goodwill acquired	3,649				—				3,649
	Amount reclassified to assets held-for-sale	(1		)		(127		)		(128		)
	Acquisition accounting, transfers and other adjustments	13				(12		)		1
	Foreign currency translation adjustments, net	4				(4		)		—
	Balance, March 31, 2014	$	8,078			$	1,849			$	9,927
Information Regarding Intangible Assets	'
		March 31, 2014												March 31, 2013
	(Dollars in millions)	Weighted		Gross				Accumulated				Net		Gross		Accumulated			Net
		Average		Carrying				Amortization				Carrying		Carrying		Amortization			Carrying
		Remaining		Amount								Amount		Amount					Amount
		Amortization
		Period
		(Years)
	Customer lists	10		$	3,384			$	(863	)		$	2,521	$	1,761	$	(672	)	$	1,089
	Service agreements	16		995				(173		)		822		1,018		(114		)	904
	Pharmacy licenses	26		1,219				(11		)		1,208		—		—			—
	Trademarks and trade names	15		371				(59		)		312		208		(46		)	162
	Technology	3		219				(173		)		46		271		(207		)	64
	Other	5		165				(52		)		113		89		(38		)	51
	Total			$	6,353			$	(1,331	)		$	5,022	$	3,347	$	(1,077	)	$	2,270

Capitalized_Software_Held_for_1

Capitalized Software Held for Sale (Tables)	12 Months Ended
	Mar. 31, 2014
Capitalized Computer Software, Net [Abstract]	'
Capitalized Software Held for Sale	'
		Years Ended March 31,
	(In millions)	2014			2013			2012
	Balance, at beginning of period	$	126		$	144		$	152
	Amounts capitalized	40			49			47
	Amortization expense	(50		)	(56		)	(53		)
	Impairment charges	(12		)	(10		)	—
	Foreign currency translations adjustments, net	(1		)	(1		)	(2		)
	Balance, at end of period	$	103		$	126		$	144

Debt_and_Financing_Activities_

Debt and Financing Activities (Tables)	12 Months Ended
	Mar. 31, 2014
Debt Disclosure [Abstract]	'
Schedule of Long-Term Debt	'
	Information regarding long-term debt is as follows:
		March 31,
	(In millions)	2014			2013
	Denominated in U.S. Dollars
	6.50% Notes due February 15, 2014	$	—		$	350
	Floating Rate Notes due September 10, 2015	400			—
	0.95% Notes due December 4, 2015	499			499
	3.25% Notes due March 1, 2016	599			599
	5.70% Notes due March 1, 2017	500			500
	1.29% Notes due March 10, 2017	700			—
	1.40% Notes due March 15, 2018	499			499
	7.50% Notes due February 15, 2019	349			349
	2.28% Notes due March 15, 2019	1,100			—
	4.75% Notes due March 1, 2021	598			598
	2.70% Notes due December 15, 2022	400			400
	2.85% Notes due March 15, 2023	400			400
	3.80% Notes due March 15, 2024	1,100			—
	7.65% Debentures due March 1, 2027	175			175
	6.00% Notes due March 1, 2041	493			493
	4.88% Notes due March 15, 2044	800			—
	Other	27			11
	Denominated in Euro and other foreign currencies
	4.00% Bonds due October 18, 2016	507			—
	4.50% Bonds due April 26, 2017	737			—
	Promissory Notes	297			—
	Bank liabilities and other	193			—
	Total debt	10,373			4,873
	Less current portion	(1,424		)	(352		)
	Total long-term debt	$	8,949		$	4,521

Pension_Benefits_Tables

Pension Benefits (Tables) (Pension Plans, Defined Benefit [Member])	12 Months Ended
	Mar. 31, 2014
Pension Plans, Defined Benefit [Member]	'
Defined Benefit Plan Disclosure [Line Items]	'
Schedule of Net Periodic Expense for Pension Plans	'
		U.S. Plans											Non-U.S. Plans
		Years Ended March 31,											Years Ended March 31,
	(In millions)	2014				2013				2012			2014				2013			2012
	Service cost - benefits earned during the year	$	4			$	4			$	4		$	6			$	3		$	3
	Interest cost on projected benefit obligation	19				21				24			11				7			7
	Expected return on assets	(20		)		(20		)		(23		)	(12		)		(8		)	(8		)
	Amortization of unrecognized actuarial loss, prior service costs and net transitional obligation	32				28				24			4				4			3
	Curtailment gain	—				—				—			(1		)		—			—
	Net periodic pension expense	$	35			$	33			$	29		$	8			$	6		$	5
Schedule of Changes in Benefit Obligations and Plan Assets for Pension Plans	'
		U.S. Plans								Non-U.S. Plans
		Years Ended March 31,								Years Ended March 31,
	(In millions)	2014				2013				2014			2013
	Change in benefit obligations
	Benefit obligation at beginning of period (1)	$	580			$	527			$	156		$	143
	Service cost	4				4				6			3
	Interest cost	19				21				11			7
	Actuarial (gain) loss	(24		)		58				15			15
	Benefit payments	(30		)		(29		)		(12		)	(6		)
	Amendments	(9		)		—				—			—
	Acquisitions	—				—				740			—
	Foreign exchange impact and other	—				(1		)		18			(6		)
	Benefit obligation at end of period (1)	$	540			$	580			$	934		$	156
	Change in plan assets
	Fair value of plan assets at beginning of period	$	290			$	284			$	135		$	126
	Actual return on plan assets	28				19				11			12
	Employer and participant contributions	12				17				12			8
	Benefits paid	(30		)		(29		)		(10		)	(6		)
	Acquisitions	—				—				426			—
	Foreign exchange impact and other	—				(1		)		16			(5		)
	Fair value of plan assets at end of period	$	300			$	290			$	590		$	135
	Funded status at end of period	$	(240	)		$	(290	)		$	(344	)	$	(21	)
	Amounts recognized on the balance sheet
	Current liabilities	$	(13	)		$	(3	)		$	(9	)	$	—
	Long-term liabilities	(227		)		(287		)		(335		)	(21		)
	Total	$	(240	)		$	(290	)		$	(344	)	$	(21	)
	-1	The benefit obligation is the projected benefit obligation.
Schedule of Projected Benefit Obligation, Accumulated Benefit Obligation and Fair Value of Plan Assets for Pension Plans	'
		U.S. Plans								Non-U.S. Plans
		March 31,								March 31,
	(In millions)	2014				2013				2014			2013
	Projected benefit obligation	$	540			$	580			$	934		$	156
	Accumulated benefit obligation	540				579				894			154
	Fair value of plan assets	300				290				590			135
Schedule of Defined Benefit Plan Amounts Recognized in Other Comprehensive Income (Loss) [Table Text Block]	'
		U.S. Plans								Non-U.S. Plans
		March 31,								March 31,
	(In millions)	2014				2013				2014			2013
	Net actuarial loss	$	188			$	251			$	71		$	59
	Prior service (credit) cost	(7		)		2				—			(2		)
	Total	$	181			$	253			$	71		$	57
Schedule of Other Changes in Plan Assets and Benefit Obligations Recognized in Other Comprehensive Income	'
		U.S. Plans											Non-U.S. Plans
		Years Ended March 31,											Years Ended March 31,
	(In millions)	2014				2013				2012			2014				2013			2012
	Net actuarial (gain) loss	$	(31	)		$	59			$	42		$	12			$	11		$	19
	Prior service credit	(8		)		—				—			—				—			—
	Amortization of:
	Net actuarial loss	(32		)		(27		)		(23		)	(4		)		(4		)	(2		)
	Prior service (cost) credit	—				(1		)		(1		)	2				—			(1		)
	Foreign exchange impact and other	(1		)		—				—			4				(4		)	—
	Total recognized in other comprehensive loss (income)	$	(72	)		$	31			$	18		$	14			$	3		$	16
Schedule of Weighted-Average Assumptions Used to Estimate Net Periodic Pension Expense and Actuarial Present Value of Benefit Obligations	'
		U.S. Plans									Non-U.S. Plans
		Years Ended March 31,									Years Ended March 31,
		2014			2013			2012			2014		2013			2012
	Net periodic pension expense
	Discount rates	3.39	%		4.11	%		4.82	%		3.95	%	4.5	%		5.42	%
	Rate of increase in compensation	4			4			4			2.66		3.1			3.45
	Expected long-term rate of return on plan assets	7.25			7.25			8			5.71		6.13			6.42
	Benefit obligation
	Discount rates	3.58	%		3.4	%		4.15	%		3.92	%	4.1	%		4.51	%
	Rate of increase in compensation	4			4			4			3.27		3.05			3.06
Schedule of Sensitivity to Changes in Weighted-Average Discount Rate for U.S. Pension Plans	'
		U.S. Plans						Non-U.S. Plans
	(In millions)	One Percentage			One Percentage			One Percentage			One Percentage
		Point Increase			Point Decrease			Point Increase			Point Decrease
	Increase (decrease) on projected benefit obligation	$	-35		$	40		$	-97		$	119
	Increase (decrease) on net periodic pension cost		-2			2			-3			4
Summary of Pension Plan Assets Using Fair Value Hierarchy by Asset Class	'
		U.S. Plans															Non-U.S. Plans
		March 31, 2014															March 31, 2014
	(In millions)	Level 1				Level 2				Level 3			Total				Level 1			Level 2			Level 3		Total
	Cash and cash equivalents	$	8			$	—			$	—		$	8			$	7		$	—		$	—	$	7
	Equity securities:
	Common and preferred stock	19				—				—			19				—			—			—		—
	Equity commingled funds	—				132				—			132				6			157			—		163
	Fixed income securities:
	Government securities	—				7				—			7				4			—			—		4
	Corporate bonds	—				22				—			22				6			236			—		242
	Mortgage-backed securities	—				10				—			10				—			—			—		—
	Asset-backed securities and other	—				22				—			22				—			—			—		—
	Fixed income commingled funds	—				63				—			63				—			45			—		45
	Other:
	Real estate funds	—				—				16			16				—			19			7		26
	Other commingled funds	—				—				—			—				3			49			—		52
	Other	—				—				—			—				—			46			5		51
	Total	$	27			$	256			$	16		299				$	26		$	552		$	12	590
	Receivables (1)												1												—
	Total												$	300											$	590
	-1	Represents pending trades at March 31, 2014.
		U.S. Plans															Non-U.S. Plans
		March 31, 2013															March 31, 2013
	(In millions)	Level 1				Level 2				Level 3			Total				Level 1			Level 2			Level 3		Total
	Cash and cash equivalents	$	—			$	8			$	—		$	8			$	3		$	—		$	—	$	3
	Equity securities:
	Common and preferred stock	20				—				—			20				—			—			—		—
	Equity commingled funds	—				127				—			127				—			82			—		82
	Fixed income securities:
	Government securities	—				12				—			12				—			—			—		—
	Corporate bonds	—				19				—			19				—			9			—		9
	Mortgage-backed securities	—				6				—			6				—			—			—		—
	Asset-backed securities and other	—				22				—			22				—			—			—		—
	Fixed income commingled funds	—				61				—			61				—			36			—		36
	Other:
	Real estate funds	—				—				14			14				—			—			5		5
	Total	$	20			$	255			$	14		289				$	3		$	127		$	5	135
	Receivables (1)												1												—
	Total												$	290											$	135
	-1	Represents pending trades at March 31, 2013.
Schedule of Reconciliation of Level 3 Plan Assets Held	'
		U.S. Plans											Non-U.S. Plans
	(In millions)	Real Estate				Other				Total			Real				Other			Total
		Funds											Estate
													Funds
	Balance at March 31, 2012	$	12			$	—			$	12		$	5			$	—		$	5
	Unrealized gain on plan assets still held	1				—				1			—				—			—
	Purchases, sales and settlements	1				—				1			—				—			—
	Balance at March 31, 2013	$	14			$	—			$	14		$	5			$	—		$	5
	Acquisitions	—				—				—			1				5			6
	Unrealized gain on plan assets still held	2				—				2			1				—			1
	Purchases, sales and settlements	—				—				—			—				—			—
	Balance at March 31, 2014	$	16			$	—			$	16		$	7			$	5		$	12

Postretirement_Benefits_Tables

Postretirement Benefits (Tables) (Other Postretirement Benefit Plan, Defined Benefit [Member])	12 Months Ended
	Mar. 31, 2014
Other Postretirement Benefit Plan, Defined Benefit [Member]	'
Defined Benefit Plan Disclosure [Line Items]	'
Schedule of Net Periodic Expense (Income) for Postretirement Welfare Benefits	'
		Years Ended March 31,
	(In millions)	2014			2013			2012
	Service cost - benefits earned during the year	$	2		$	2		$	2
	Interest cost on accumulated benefit obligation	5			6			7
	Amortization of unrecognized actuarial gain and prior service credit	(1		)	(2		)	(1		)
	Curtailment gain	(2		)	—			—
	Net periodic postretirement expense	$	4		$	6		$	8
Schedule of Changes in Benefit Obligations for Postretirement Welfare Plans	'
		Years Ended March 31,
	(In millions)	2014			2013
	Benefit obligation at beginning of period	$	131		$	144
	Service cost	2			2
	Interest cost	5			6
	Actuarial gain	(2		)	(9		)
	Benefit payments	(15		)	(12		)
	Curtailment gain	(2		)	—
	Benefit obligation at end of period	$	119		$	131

Hedging_Activities_Derivative_

Hedging Activities Derivative Fair Value Table (Tables)	12 Months Ended
	Mar. 31, 2014
Derivative Instruments and Hedging Activities Disclosure [Abstract]	'
Fair Value, by Balance Sheet Grouping [Table Text Block]	'
	Information regarding the fair value of derivatives on a gross basis is as follows:
		Balance Sheet	31-Mar-14						31-Mar-13
		Caption	Fair Value of				U.S. Dollar Notional		Fair Value of				U.S Dollar Notional
			Derivative						Derivative
	(In millions)		Asset		Liability				Asset		Liability
	Derivatives designated for hedge accounting
	Foreign exchange	Prepaid expenses and other	$	4	$	—	$	64	$	—	$	—	$	—
	contracts (current)
	Foreign exchange	Other assets	27		—		399		5		—		463
	contracts (non-current)
	Foreign exchange	Other accrued liabilities	—		—		—		—		1		41
	contracts (current)
	Total		$	31	$	—			$	5	$	1
	Derivatives not designated for hedge accounting
	Foreign exchange	Prepaid expenses and other	$	2	$	—	$	255	$	5	$	—	$	177
	contracts (current)
	Foreign exchange	Other accrued liabilities	—		13		836		—		—		—
	contracts (current)
	Interest rate swap contracts (current)	Other accrued liabilities	—		1		96		—		—		—
	Total		$	2	$	14			$	5	$	—

Fair_Value_Measurements_Tables

Fair Value Measurements (Tables)	12 Months Ended
	Mar. 31, 2014
Fair Value Disclosures [Abstract]	'
Fair Value Measurements, Recurring [Table Text Block]	'
		March 31, 2014								March 31, 2013
	(In millions)	Level 1		Level 2		Level 3		Total		Level 1		Level 2		Level 3		Total
	Cash Equivalents
	Money market funds (1)	$	2,284	$	—	$	—	$	2,284	$	1,036	$	—	$	—	$	1,036
	Time deposits (2)	—		12		—		12		—		95		—		95
	Repurchase agreements (2)	569		—		—		569		447		—		—		447
	Total cash equivalents	$	2,853	$	12	$	—	$	2,865	$	1,483	$	95	$	—	$	1,578
	(1) Gross unrealized gain and losses were not material for the years ended March 31, 2014 and 2013. Based on quoted prices of identical investments.
	(2) The carrying amounts of these cash equivalents approximated their estimated fair values because of their short maturities.

Lease_Obligations_Tables

Lease Obligations (Tables)	12 Months Ended
	Mar. 31, 2014
Leases, Operating [Abstract]	'
Schedule of Future Minimum Rental Payments for Operating Leases	'
	(In millions)	Noncancelable
		Operating
		Leases
	2015	$	358
	2016	299
	2017	246
	2018	193
	2019	168
	Thereafter	806
	Total minimum lease payments (1)	$	2,070
	-1	Minimum lease payments have not been reduced by minimum sublease rentals of $44 million due under future noncancelable subleases.

Other_Commitments_and_Continge1

Other Commitments and Contingent Liabilities (Tables) (Average Wholesale Price Litigation [Member])	12 Months Ended
	Mar. 31, 2014
Average Wholesale Price Litigation [Member]	'
Loss Contingencies [Line Items]	'
Litigation Reserve and Expense	'
		Years Ended March 31,
	(In millions)	2014			2013			2012
	AWP litigation reserve at beginning of period	$	42		$	453		$	330
	Charges incurred	68			72			149
	Payments made	(105		)	(483		)	(26		)
	AWP litigation reserve at end of period	$	5		$	42		$	453

Stockholders_Equity_Tables

Stockholders' Equity (Tables)	12 Months Ended
	Mar. 31, 2014
Stockholders' Equity Note [Abstract]	'
Schedule of Shares Repurchased Over Last Three Years	'
		Share Repurchases (1)
	(In millions, except price per share data)		Total		Average Price			Approximate
			Number of Shares Purchased (2) (3)		Paid Per Share			Dollar Value of
								Shares that May
								Yet Be Purchased
								Under the
								Programs
	Balance, March 31, 2011							$	499
	Share repurchase plans approved:
	Apr-11							1,000
	Jan-12							650
	Shares repurchased		20		$	83.47		(1,850		)
	Balance, March 31, 2012							$	299
	Share repurchase plans approved:
	Apr-12							700
	Jan-13							500
	Shares repurchased		13		$	100.82		(1,159		)
	Balance, March 31, 2013							$	340
	Shares repurchased		—		$	—		—
	Balance, March 31, 2014							$	340
	-1	This table does not include shares tendered to satisfy the exercise price in connection with cashless exercises of employee stock options or shares tendered to satisfy tax withholding obligations in connection with employee equity awards.
	-2	All of the shares purchased were part of the publicly announced programs.
	-3	The number of shares purchased reflects rounding adjustments.
Schedule of Comprehensive Income (Loss) [Table Text Block]	'
		Years Ended March 31,
	(In millions)	2014			2013			2012
	Foreign currency translation adjustments
	Foreign currency translation adjustments arising during period, net of income tax expense (benefit) of nil, ($2) and $2 (1)	$	9		$	(52	)	$	(56	)
	Reclassified to income statement, net of income tax expense of $24, nil and nil (2)	44			—			—
		53			(52		)	(56		)
	Unrealized losses on cash flow hedges
	Unrealized losses on cash flow hedges arising during period, net of income tax benefit of nil, nil and nil	(6		)	—			(5		)
	Changes in retirement-related benefit plans
	Net actuarial gain (loss) and prior service credit (cost) arising during period, net of income tax (benefit) of $16, ($22) and ($18)	17			(40		)	(38		)
	Amortization of actuarial loss, prior service cost and transition obligation, net of income tax expense of $12, $12 and $9 (3)	22			18			17
	Foreign currency translation adjustments, net of income tax expense of nil, nil and nil	(4		)	4			—
	Reclassified to income statement, net of income tax expense of $1, nil and nil	1			—			—
		36			(18		)	(21		)
	Other Comprehensive Income (Loss), net of tax	$	83		$	(70	)	$	(82	)
	-1	The 2014 amounts include net foreign currency translation gain of $21 million attributable to noncontrolling interests.
	-2	As a result of our sale of our 49% equity interest in Nadro, foreign currency translation net losses of $44 million were reclassified from AOCI to other income, within our consolidated statement of operations. Such losses were previously considered in our impairment evaluation of the investment when we committed to a plan to sell the investment during the fourth quarter of 2013, and accordingly did not impact earnings for 2014.
	-3	Pre-tax amount was reclassified into cost of sales and operating expenses in the consolidated statements of operations. The related tax expense (benefit) was reclassified into income tax expense in the consolidated statements of operations.
Accumulated Other Comprehensive Income	'
	(In millions)	Foreign Currency Translation Adjustments, Net of Tax			Unrealized Losses on Cash Flow Hedges,			Unrealized Net Loss and Other Components of Benefit Plans, Net of Tax			Total Accumulated Other Comprehensive Income (Loss)
					Net of Tax
	Balance at March 31, 2012	$	188		$	(5	)	$	(178	)	$	5
	Other comprehensive loss before reclassifications	(52		)	—			(18		)	(70		)
	Other comprehensive loss	(52		)	—			(18		)	(70		)
	Balance at March 31, 2013	$	136		$	(5	)	$	(196	)	$	(65	)
	Other comprehensive income (loss) before reclassifications	(12		)	(6		)	35			17
	Amounts reclassified to earnings	44			—			1			45
	Other comprehensive income (loss)	32			(6		)	36			62
	Balance at March 31, 2014	$	168		$	(11	)	$	(160	)	$	(3	)

Segments_of_Business_Tables

Segments of Business (Tables)	12 Months Ended
	Mar. 31, 2014
Segment Reporting [Abstract]	'
Schedule of Segment Information	'
		Years Ended March 31,
	(In millions)	2014			2013			2012
	Revenues
	Distribution Solutions (1)
	North America pharmaceutical distribution and services	$	123,930		$	115,443		$	116,279
	International pharmaceutical distribution and services	4,848			—			—
	Medical-Surgical distribution & services	5,648			3,603			3,145
	Total Distribution Solutions	134,426			119,046			119,424
	Technology Solutions - products and services	3,183			3,023			2,897
	Total Revenues	$	137,609		$	122,069		$	122,321
	Operating profit
	Distribution Solutions	$	2,461		$	2,195		$	2,219
	Technology Solutions	387			308			338
	Total	2,848			2,503			2,557
	Corporate Expenses, Net	(449		)	(335		)	(413		)
	Interest expense	(303		)	(240		)	(251		)
	Income From Continuing Operations Before Income Taxes	$	2,096		$	1,928		$	1,893
	Depreciation and amortization (2)
	Distribution Solutions	$	448		$	265		$	224
	Technology Solutions	136			145			152
	Corporate	120			120			117
	Total	$	704		$	530		$	493
	Expenditures for long-lived assets (3)
	Distribution Solutions	$	180		$	163		$	175
	Technology Solutions	42			28			18
	Corporate	52			41			28
	Total	$	274		$	232		$	221
	Revenues, net by geographic area (4)
	United States	$	122,426		$	112,109		$	112,051
	Foreign	15,183			9,960			10,270
	Total	$	137,609		$	122,069		$	122,321
	-1	Revenues derived from services represent less than 2% of this segment’s total revenues.
	-2	Amounts primarily include amortization of acquired intangible assets purchased in connection with acquisitions, capitalized software held for sale and capitalized software for internal use.
	-3	Long-lived assets consist of property, plant and equipment.
	-4	Net revenues were attributed to geographic areas based on the customers’ shipment locations.
Segment Assets and Property, Plant and Equipment, Net by Geographic Areas	'
		March 31,
	(In millions)	2014			2013
	Segment assets
	Distribution Solutions	$	42,758		$	27,307
	Technology Solutions	3,324			3,829
	Total	46,082			31,136
	Corporate
	Cash and cash equivalents	4,193			2,456
	Other	1,484			1,194
	Total	$	51,759		$	34,786
	Property, plant and equipment, net
	United States	$	1,246		$	1,205
	Foreign	976			116
	Total	$	2,222		$	1,321

Quarterly_Financial_Informatio1

Quarterly Financial Information (Unaudited) (Tables)	12 Months Ended
	Mar. 31, 2014
Quarterly Financial Information Disclosure [Abstract]	'
Schedule of Quarterly Financial Information	'
	(In millions, except per share amounts)	First		Second			Third			Fourth
		Quarter		Quarter			Quarter			Quarter
	Fiscal 2014
	Revenues	$	32,208	$	32,954		$	34,306		$	38,141
	Gross profit (1)	1,920		2,009			1,840			2,540
	Income after income taxes
	Continuing operations (1) (2)	$	420	$	416		$	156		$	362
	Discontinued operations (3)	4		(12		)	(92		)	4
	Net income	424		404			64			366
	Net loss attributable to noncontrolling interests (4)	—		—			—			5
	Net income attributable to McKesson	$	424	$	404		$	64		$	371
	Earnings (loss) per common share attributable
	to McKesson (5)
	Diluted
	Continuing operations	$	1.81	$	1.79		0.67			$	1.56
	Discontinued operations	0.02		(0.05		)	(0.39		)	0.02
	Total	$	1.83	$	1.74		$	0.28		$	1.58
	Basic
	Continuing operations	$	1.84	$	1.82		0.68			$	1.59
	Discontinued operations	0.02		(0.06		)	(0.40		)	0.02
	Total	$	1.86	$	1.76		$	0.28		$	1.61
	-1	Financial results for the second, third and fourth quarters of 2014 includes pre-tax charges in our Distribution Solutions segment related to our LIFO method of accounting for inventories of $44 million, $142 million and $125 million, which were recorded in cost of sales. Fourth quarter 2014 also includes a $50 million pre-tax charge to cost of sales within our Distribution Solutions segment representing the reversal of a step-up to fair value of Celesio’s inventory at the date of acquisition. Our after-tax portion of this charge (after allocation to noncontrolling interests), was $28 million.
	-2	Financial results for the third quarter of 2014 include an income tax charge of $122 million relating to a litigation with the Canadian Revenue Agency.
	-3	Financial results for the third quarter of 2014, include an $80 million of after-tax impairment charge related to our International Technology Business.
	-4	Primarily represents the noncontrolling shareholders’ portion of net loss from Celesio.
	-5	Certain computations may reflect rounding adjustments.
	(In millions, except per share amounts)	First		Second			Third			Fourth
		Quarter		Quarter			Quarter			Quarter
	Fiscal 2013
	Revenues	$	30,699	$	29,755		$	31,099		$	30,516
	Gross profit	1,561		1,683			1,645			1,959
	Income after income taxes
	Continuing operations (1) (2) (3)	$	379	$	399		$	306		$	263
	Discontinued operations	1		2			(8		)	(4		)
	Net income	380		401			298			259
	Net loss attributable to noncontrolling interests	—		—			—			—
	Net income attributable to McKesson	$	380	$	401		$	298		$	259
	Earnings per common share attributable
	to McKesson (4)
	Diluted
	Continued operations	$	1.58	$	1.66		$	1.27		$	1.11
	Discontinued operations	—		0.01			(0.03		)	(0.01		)
	Total	$	1.58	$	1.67		$	1.24		$	1.1
	Basic
	Continuing operations	$	1.61	$	1.69		$	1.3		$	1.13
	Discontinued operations	—		0.01			(0.03		)	(0.01		)
	Total	$	1.61	$	1.7		$	1.27		$	1.12
	-1	Financial results for the first quarter of 2013 include an $81 million pre-tax gain on business combination, which was recorded as a reduction to operating expenses within our Corporate segment.
	-2	Financial results for the third quarter of 2013 include a $40 million pre-tax charge for a legal dispute in our Canadian business which was recorded in operating expenses within our Distribution Solutions segment.
	-3	Financial results for the fourth quarter of 2013 include a pre-tax impairment charge for an equity investment of $191 million recorded in other income, net within our Distribution Solutions segment. Financial results for the fourth quarter of 2013 also include $46 million of pre-tax impairment charges recorded in our Technology Solutions segment of which $36 million was recorded in operating expenses and $10 million was recorded in cost of sales.
	-4	Certain computations may reflect rounding adjustments.

Significant_Accounting_Policie2

Significant Accounting Policies (Narrative) (Details) (USD $)

3 Months Ended

12 Months Ended

3 Months Ended

12 Months Ended

Mar. 31, 2014

Mar. 31, 2014

Mar. 31, 2013

Mar. 31, 2012

Mar. 31, 2014

Dec. 31, 2013

Sep. 30, 2013

Mar. 31, 2013

Mar. 31, 2014

Mar. 31, 2014

Mar. 31, 2014

Mar. 31, 2014

Mar. 31, 2014

Mar. 31, 2014

Mar. 31, 2014

Mar. 31, 2014

Mar. 31, 2014

Distribution Solutions [Member]

Distribution Solutions [Member]

Distribution Solutions [Member]

Distribution Solutions [Member]

Capitalized Software Held for Sale [Member]

Minimum [Member]

Minimum [Member]

Maximum [Member]

Maximum [Member]

Sales Revenue, Net [Member]

Accounts Receivable [Member]

CVS Caremark Corporation [Member]

CVS Caremark Corporation [Member]

Capitalized Software Held for Internal Use [Member]

Capitalized Software Held for Internal Use [Member]

Customer Concentration Risk [Member]

Customer Concentration Risk [Member]

Sales Revenue, Net [Member]

Accounts Receivable [Member]

Distribution Solutions [Member]

Distribution Solutions [Member]

Customer Concentration Risk [Member]

Customer Concentration Risk [Member]

Distribution Solutions [Member]

Distribution Solutions [Member]

Significant Accounting Policies [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Concentration Risk, Percentage

'

'

'

'

'

'

'

'

'

'

'

'

'

48.00%

32.00%

16.00%

12.00%

Percentage of LIFO Inventory

67.00%

67.00%

80.00%

'

'

'

'

'

'

'

'

'

'

'

'

'

'

LIFO reserve, net of LCM adjustments

$431,000,000

$431,000,000

$120,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Net LIFO expense

'

311,000,000

13,000,000

11,000,000

125,000,000

142,000,000

44,000,000

'

'

'

'

'

'

'

'

'

'

Excess of LIFO inventory over FIFO inventory

'

'

60,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

LCM credit (charges) recorded

'

60,000,000

16,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Property, plant and equipment, useful life

'

'

'

'

'

'

'

'

'

'1 year

'

'30 years

'

'

'

'

'

Intangible assets, useful life

'

'

'

'

'

'

'

'

'3 years

'1 year

'1 year

'38 years

'10 years

'

'

'

'

Capitalized computer software, net

514,000,000

514,000,000

465,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Tax Recognized, Percent Likely Being Realized

'

50.00%

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Capitalized software held for internal use, accumulated amortization

1,004,000,000

1,004,000,000

1,011,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Sales returns from customers

'

1,900,000,000

1,900,000,000

1,600,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

Supplier reserves

'

'

'

'

$181,000,000

'

'

$164,000,000

'

'

'

'

'

'

'

'

'

Business combination, consolidation percent

100.00%

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Significant_Accounting_Policie3

Significant Accounting Policies (Concentrations of Credit Risk) (Details) (Customer Concentration Risk [Member], Distribution Solutions [Member])	12 Months Ended
	Mar. 31, 2014
Sales Revenue, Net [Member]	'
Significant Accounting Policies [Line Items]	'
Concentration Risk, Percentage	48.00%
Accounts Receivable [Member]	'
Significant Accounting Policies [Line Items]	'
Concentration Risk, Percentage	32.00%
CVS Caremark Corporation [Member] | Sales Revenue, Net [Member]	'
Significant Accounting Policies [Line Items]	'
Concentration Risk, Percentage	16.00%
CVS Caremark Corporation [Member] | Accounts Receivable [Member]	'
Significant Accounting Policies [Line Items]	'
Concentration Risk, Percentage	12.00%

Business_Combinations_Narrativ

Business Combinations (Narrative) (Details)

2 Months Ended

3 Months Ended

12 Months Ended

0 Months Ended

2 Months Ended

3 Months Ended

3 Months Ended

1 Months Ended

3 Months Ended

12 Months Ended

3 Months Ended

3 Months Ended

1 Months Ended

3 Months Ended

12 Months Ended

3 Months Ended

3 Months Ended

3 Months Ended

3 Months Ended

12 Months Ended

Mar. 31, 2014

Mar. 31, 2014

Mar. 31, 2014

Mar. 31, 2013

Mar. 31, 2012

Feb. 06, 2014

Feb. 06, 2014

Mar. 31, 2014

Mar. 31, 2014

Feb. 28, 2014

Mar. 31, 2014

Mar. 31, 2014

Mar. 31, 2014

Feb. 28, 2013

Mar. 31, 2014

Mar. 31, 2014

Feb. 22, 2013

Mar. 31, 2014

Mar. 31, 2014

Jun. 30, 2012

Apr. 06, 2012

Jun. 30, 2012

Mar. 31, 2012

Sep. 30, 2012

Mar. 31, 2012

Mar. 31, 2012

Mar. 31, 2014

Feb. 06, 2014

Mar. 31, 2014

Feb. 06, 2014

Mar. 31, 2014

Mar. 31, 2014

Mar. 31, 2014

Mar. 31, 2014

Mar. 31, 2014

Mar. 31, 2014

Mar. 31, 2014

Mar. 31, 2014

Feb. 06, 2014

Apr. 06, 2012

Feb. 06, 2014

Mar. 31, 2014

Mar. 31, 2014

Mar. 31, 2014

Feb. 22, 2013

Feb. 22, 2013

Sep. 30, 2012

Apr. 06, 2012

Mar. 31, 2012

Mar. 31, 2012

Mar. 31, 2012

Apr. 22, 2014

Mar. 31, 2014

Mar. 31, 2014

Mar. 31, 2013

Mar. 31, 2012

USD ($)

USD ($)

USD ($)

USD ($)

USD ($)

Celesio [Member]

Celesio [Member]

Celesio [Member]

Celesio [Member]

Celesio [Member]

Celesio [Member]

Celesio [Member]

Celesio [Member]

PSS World Medical [Member]

PSS World Medical [Member]

PSS World Medical [Member]

PSS World Medical [Member]

PSS World Medical [Member]

PSS World Medical [Member]

Corporate Headquarters [Member]

Corporate Headquarters [Member]

Corporate Headquarters [Member]

Katz Group [Member]

Katz Group [Member]

Katz Group [Member]

Katz Group [Member]

The 2014 Bonds [Member]

The 2014 Bonds [Member]

The 2018 Bonds [Member]

The 2018 Bonds [Member]

The 2014 and 2018 Bonds [Member]

Private Purchases [Member]

Private Purchases [Member]

Private Purchases [Member]

Private Purchases [Member]

Noncontrolling Interest [Member]

Noncontrolling Interest [Member]

Franz Haniel Cie GmbH [Member]

Franz Haniel Cie GmbH [Member]

Fair Value, Inputs, Level 2 [Member]

Fair Value, Inputs, Level 3 [Member]

Fair Value, Inputs, Level 3 [Member]

Fair Value, Inputs, Level 3 [Member]

Fair Value, Inputs, Level 3 [Member]

Fair Value, Inputs, Level 3 [Member]

Fair Value, Inputs, Level 3 [Member]

Fair Value, Inputs, Level 3 [Member]

Fair Value, Inputs, Level 3 [Member]

Fair Value, Inputs, Level 3 [Member]

Fair Value, Inputs, Level 3 [Member]

Fair Value, Inputs, Level 3 [Member]

Subsequent Event [Member]

Cost of Sales [Member]

Cost of Sales [Member]

Cost of Sales [Member]

Cost of Sales [Member]

USD ($)

EUR (€)

USD ($)

EUR (€)

Trademarks [Member]

Customer Relationships [Member]

Pharmacy Licenses [Member]

USD ($)

USD ($)

USD ($)

Customer Relationships [Member]

Trademarks and Trade Names [Member]

USD ($)

USD ($)

Building and Building Improvements [Member]

USD ($)

USD ($)

Amounts Recognized As Of Acquisition Date As Adjusted [Member]

Celesio [Member]

Celesio [Member]

Celesio [Member]

Celesio [Member]

Celesio [Member]

Celesio [Member]

The 2014 Bonds [Member]

The 2018 Bonds [Member]

The 2014 and 2018 Bonds [Member]

Celesio [Member]

The 2014 and 2018 Bonds [Member]

Celesio [Member]

Celesio [Member]

Corporate Headquarters [Member]

Celesio [Member]

Celesio [Member]

Celesio [Member]

Celesio [Member]

PSS World Medical [Member]

PSS World Medical [Member]

PSS World Medical [Member]

Corporate Headquarters [Member]

Katz Group [Member]

Katz Group [Member]

Katz Group [Member]

Celesio [Member]

USD ($)

USD ($)

USD ($)

USD ($)

USD ($)

convertiblebond

EUR (€)

convertiblebond

EUR (€)

USD ($)

Celesio [Member]

Celesio [Member]

Celesio [Member]

USD ($)

Celesio [Member]

USD ($)

USD ($)

USD ($)

Trademarks [Member]

Customer Relationships [Member]

Pharmacy Licenses [Member]

USD ($)

Customer Relationships [Member]

Trademarks and Trade Names [Member]

USD ($)

Amounts Recognized As Of Acquisition Date As Adjusted [Member]

Trademarks and Trade Names [Member]

Service Agreements [Member]

convertiblebond

convertiblebond

USD ($)

USD ($)

USD ($)

USD ($)

USD ($)

USD ($)

USD ($)

Amounts Recognized As Of Acquisition Date As Adjusted [Member]

Amounts Recognized As Of Acquisition Date As Adjusted [Member]

USD ($)

USD ($)

Business Acquisition [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Effective Date of Acquisition

'

'

'

'

'

'

'

'

6-Feb-14

'

'

'

'

22-Feb-13

'

'

'

'

'

6-Apr-12

'

'

25-Mar-12

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Percentage of Voting Interests Acquired

'

'

'

'

'

77.60%

77.60%

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Name of Acquired Entity

'

'

'

'

'

'

'

'

'Celesio AG

'

'

'

'

'

'PSS World Medical, Inc. (bPSS World Medicalb)

'

'

'

'

'

'

'

'

'Drug Trading Company Limited, the independent banner business of the Katz Group Canada Inc. (bKatz Groupb), and Medicine Shoppe Canada Inc., the franchise business of the Katz Group (collectively, bKatz Assetsb)

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Cash Paid for Acquisition

'

'

'

'

'

'

'

'

$4,500,000,000

'

'

'

'

$1,300,000,000

'

'

'

'

'

$90,000,000

'

'

'

'

$925,000,000

'

'

'

'

'

$951,000,000

'

'

'

$63,000,000

'

'

$4,128,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Subsidiary or Equity Method Investee, Cumulative Percentage Ownership after All Transactions

'

'

'

'

'

75.60%

75.60%

75.40%

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Business Combination, Consideration Transferred, Liabilities Incurred

'

'

'

'

'

'

'

'

2,300,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Description of Acquired Entity

'

'

'

'

'

'

'

'

'Celesio is an international wholesale and retail company and a provider of logistics and services to the pharmaceutical and healthcare sectors. Celesiobs headquarters is in Stuttgart, Germany and it operates in 14 countries around the world

'

'

'

'

'

'PSS World Medical markets and distributes medical products and services throughout the United States.

'

'

'

'

'

'

'

'

'

'The acquisition of the assets from the Drug Trading Company Limited consists of a marketing and purchasing arm of independently owned pharmacies in Canada. The acquisition of Medicine Shoppe Canada Inc. consists of the franchise business of providing services to independent pharmacies in Canada.

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Common Shares Acquired

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

129,300,000

'

'

'

'

'

'

'

'

'

'

'

'

1,000,000

'

'

'

'

Per Share Price of Outstanding Shares Acquired

'

'

'

'

'

'

€ 23.50

'

'

'

'

'

'

'

'

'

$29

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Convertible bonds acquired

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

4,840

'

2,180

'

'

'

303

216

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Celesio convertible bonds issued

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

7,000

'

3,500

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Finite-Lived Intangibles

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

3,018,000,000

172,000,000

1,574,000,000

1,202,000,000

568,000,000

539,000,000

15,000,000

'

442,000,000

114,000,000

318,000,000

'

'

'

'

'

Integration Related Costs

89,000,000

'

'

0

0

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

3,000,000

0

0

Payments To Acquire Business, Convertible Bonds Of Acquiree

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

350,000,000

'

350,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Debt Conversion, Converted Instrument, Shares Issued

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

11,400,000

'

11,900,000

700,000

'

'

'

'

9,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Conversion of Celesio convertible bonds

'

313,000,000

313,000,000

0

0

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Business Combination Inventory Step-Up Fair Value After-tax Charge

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

28,000,000

'

'

'

Business Combination, Acquired Bonds Converted

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

2,180

'

'

'

'

139

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Business Acquisition Tender Offer Price

'

'

'

'

'

'

'

'

'

€ 23.50

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Noncontrolling interests

'

'

'

'

'

-1,500,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Business Combination, Cash Proceeds From Bonds Redeemed

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

30,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Purchase Price for Acquisition

'

'

'

'

'

'

'

'

'

'

'

'

'

1,900,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Current Portion of Long-Term Debt Acquired

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

600,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Weighted average useful life, intangible sssets

'

'

'

'

'

'

'

'

'17 years

'

'14 years

'11 years

'26 years

'

'9 years

'

'

'9 years

'2 years

'

'

'

'

'

'20 years

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Previously Held Percentage of Building

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

50.00%

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Currently Acquired Percentage of Building

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

50.00%

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Goodwill, Acquired During Period

'

'

3,649,000,000

1,421,000,000

'

'

'

'

'

'

'

'

'

'

'

1,149,000,000

'

'

'

'

'

'

'

'

'

512,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Gain on business combination

'

'

0

81,000,000

0

'

'

'

'

'

'

'

'

'

'

'

'

'

'

81,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Business combination gain, after-tax

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

51,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Net assets, fair value

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

180,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Building, fair value

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

113,000,000

'

'

'

'

'

'

'

'

Land, fair value

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

58,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Property, plant and equipment, useful life

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'30 years

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Goodwill, Expected Tax Deductible Amount

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

290,000,000

'

290,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Business Combination, Pro Forma Information, Revenue of Acquiree since Acquisition Date, Actual

$4,800,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Business_Combinations_Celesio_

Business Combinations (Celesio Pro Forma) (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2014		Mar. 31, 2013
Business Acquisition, Pro Forma Information [Line Items]	'		'
Net revenues	$161,483		$150,395
Net income attributable to McKesson	$1,493	[1]	$1,202	[1]
[1]	(1)Includes $89 million of after-tax acquisition-related expenses and a $28 million after-tax charge associated with our portion of the reversal of a step-up to fair value of Celesiobs inventory at the date of acquisition. These expenses were incurred in 2014; for pro forma purposes, they are allocated to 2013.

Business_Combinations_Fair_Val

Business Combinations (Fair Value Of Assets Acquired And Liabilities Assumed) (Details) (USD $)	Mar. 31, 2014	Feb. 06, 2014	Mar. 31, 2013	Mar. 31, 2012
In Millions, unless otherwise specified
Business Acquisition [Line Items]	'	'	'	'
Receivables	'	$3,425	'	'
Goodwill	9,927	'	6,405	5,032
Celesio [Member]	'	'	'	'
Business Acquisition [Line Items]	'	'	'	'
Current assets, net of cash and cash equivalents acquired	'	2,413	'	'
Goodwill	'	3,570	'	'
Other long-term assets	'	1,272	'	'
Current liabilities	'	-4,096	'	'
Other long-term liabilities	'	-1,293	'	'
Net assets acquired, less cash and cash equivalents	'	5,997	'	'
Noncontrolling interests	'	-1,500	'	'
Net assets acquired, net of cash and cash equivalents	'	4,497	'	'
Fair Value, Inputs, Level 1 [Member]	'	'	'	'
Business Acquisition [Line Items]	'	'	'	'
Noncontrolling interests	'	-1,500	'	'
Fair Value, Inputs, Level 2 [Member] | Celesio [Member]	'	'	'	'
Business Acquisition [Line Items]	'	'	'	'
Long-term debt	'	-322	'	'
Fair Value, Inputs, Level 3 [Member] | Celesio [Member]	'	'	'	'
Business Acquisition [Line Items]	'	'	'	'
Intangible assets	'	3,018	'	'
Celesio [Member] | Fair Value, Inputs, Level 2 [Member]	'	'	'	'
Business Acquisition [Line Items]	'	'	'	'
Short-term borrowings and current portion of long-term debt	'	-1,990	'	'
Noncontrolling Interest [Member] | Fair Value, Inputs, Level 1 [Member]	'	'	'	'
Business Acquisition [Line Items]	'	'	'	'
Noncontrolling interests	'	-1,412	'	'
Subsidiary noncontrolling interest [Member] | Fair Value, Inputs, Level 1 [Member]	'	'	'	'
Business Acquisition [Line Items]	'	'	'	'
Noncontrolling interests	'	-88	'	'
Noncontrolling Interest [Member]	'	'	'	'
Business Acquisition [Line Items]	'	'	'	'
Noncontrolling interests	'	-1,500	'	'
Noncontrolling Interest [Member] | Celesio [Member]	'	'	'	'
Business Acquisition [Line Items]	'	'	'	'
Noncontrolling interests	'	($1,500)	'	'

Business_Combinations_Acquisit

Business Combinations (Acquisition Expenses And Related Adjustments By Segment) (Details) (USD $)	2 Months Ended	12 Months Ended
	Mar. 31, 2014	Mar. 31, 2014	Mar. 31, 2013	Mar. 31, 2012
Business Acquisition, Pro Forma Information, Nonrecurring Adjustment [Line Items]	'	'	'	'
Total Acquisition Expenses and Related Adjustments	$218,000,000	$218,000,000	$1,000,000	$26,000,000
Integration Related Costs	89,000,000	'	0	0
Gain on business combination	'	0	81,000,000	0
Operating Expense [Member]	'	'	'	'
Business Acquisition, Pro Forma Information, Nonrecurring Adjustment [Line Items]	'	'	'	'
Transaction closing expenses	'	39,000,000	16,000,000	3,000,000
Total Acquisition and Integration Related Costs	'	155,000,000	-10,000,000	26,000,000
Restructuring, severance and relocation	'	43,000,000	30,000,000	3,000,000
Integration Related Costs	'	73,000,000	25,000,000	20,000,000
Gain on business combination	'	0	81,000,000	0
Distribution Solutions [Member]	'	'	'	'
Business Acquisition, Pro Forma Information, Nonrecurring Adjustment [Line Items]	'	'	'	'
Total Acquisition and Integration Related Costs	'	119,000,000	47,000,000	24,000,000
Technology Solutions [Member]	'	'	'	'
Business Acquisition, Pro Forma Information, Nonrecurring Adjustment [Line Items]	'	'	'	'
Total Acquisition and Integration Related Costs	'	15,000,000	7,000,000	1,000,000
Corporate [Member]	'	'	'	'
Business Acquisition, Pro Forma Information, Nonrecurring Adjustment [Line Items]	'	'	'	'
Total Acquisition and Integration Related Costs	'	21,000,000	-64,000,000	1,000,000
Corporate - Other Income	'	-14,000,000	0	0
Corporate - Interest Expense	'	46,000,000	11,000,000	0
Corporate [Member] | PSS World Medical [Member] | Bridge Loan [Member]	'	'	'	'
Business Acquisition, Pro Forma Information, Nonrecurring Adjustment [Line Items]	'	'	'	'
Corporate - Interest Expense	'	'	11,000,000	'
Operating Segments [Member]	'	'	'	'
Business Acquisition, Pro Forma Information, Nonrecurring Adjustment [Line Items]	'	'	'	'
Total Acquisition and Integration Related Costs	'	155,000,000	-10,000,000	26,000,000
Cost of Sales [Member]	'	'	'	'
Business Acquisition, Pro Forma Information, Nonrecurring Adjustment [Line Items]	'	'	'	'
Integration Related Costs	'	$3,000,000	$0	$0

Discontinued_Operations_Narrat

Discontinued Operations (Narrative) (Details) (USD $)	12 Months Ended			3 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013	Mar. 31, 2012	Dec. 31, 2013	Dec. 31, 2013
				International Technology [Member]	Hospital Automation [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]	'	'	'	'	'
Goodwill and Intangible Asset Impairment	'	'	'	$80	'
Goodwill and Intangible Asset Impairment, After-tax Charge	'	'	'	80	'
Proceeds from Divestiture of Businesses	'	'	'	'	55
Discontinued Operation, Gain (Loss) from Disposal of Discontinued Operation, before Income Tax	5	0	0	'	5
Discontinued Operation, Gain (Loss) on Disposal of Discontinued Operation, Net of Tax	'	'	'	'	7
Assets of Disposal Group, Including Discontinued Operation	267	'	'	'	'
Liabilities of Disposal Group, Including Discontinued Operation	$248	'	'	'	'

Discontinued_Operations_Discon1

Discontinued Operations Discontinued Operations (Schedule of Results from Discontinued Operations) (Details) (USD $)

3 Months Ended

12 Months Ended

In Millions, unless otherwise specified

Mar. 31, 2014

Dec. 31, 2013

Sep. 30, 2013

Jun. 30, 2013

Mar. 31, 2013

Dec. 31, 2012

Sep. 30, 2012

Jun. 30, 2012

Mar. 31, 2014

Mar. 31, 2013

Mar. 31, 2012

Discontinued Operations and Disposal Groups [Abstract]

'

'

'

'

'

'

'

'

'

'

'

Revenues

'

'

'

'

'

'

'

'

$421

$386

$413

Income (loss) from discontinued operations

'

'

'

'

'

'

'

'

-102

-9

26

Loss on sale

'

'

'

'

'

'

'

'

-5

0

0

Income (loss) from discontinued operations

'

'

'

'

'

'

'

'

-107

-9

26

Income tax (expense) benefit

'

'

'

'

'

'

'

'

11

0

-2

Income (Loss) from Discontinued Operations, Net of Tax

$4

[1]

($92)

[1]

($12)

[1]

$4

[1]

($4)

($8)

$2

$1

($96)

($9)

$24

[1]

Financial results for the third quarter of 2014, include an $80 million of after-tax impairment charge related to our International Technology Business.

Asset_Impairments_and_Product_1

Asset Impairments and Product Alignment Charges (Narrative) (Details) (USD $)

12 Months Ended

3 Months Ended

12 Months Ended

3 Months Ended

12 Months Ended

3 Months Ended

In Millions, unless otherwise specified

Mar. 31, 2014

Mar. 31, 2013

Mar. 31, 2012

Dec. 31, 2013

Mar. 31, 2013

Mar. 31, 2014

Mar. 31, 2013

Dec. 31, 2013

Mar. 31, 2013

Dec. 31, 2013

Mar. 31, 2013

Dec. 31, 2013

Mar. 31, 2012

Mar. 31, 2012

Mar. 31, 2012

Mar. 31, 2012

Mar. 31, 2012

Mar. 31, 2012

Mar. 31, 2012

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2013

Technology Solutions [Member]

Technology Solutions [Member]

Technology Solutions [Member]

Technology Solutions [Member]

Technology Solutions [Member]

Technology Solutions [Member]

Technology Solutions [Member]

Technology Solutions [Member]

Technology Solutions [Member]

Technology Solutions [Member]

Technology Solutions [Member]

Technology Solutions [Member]

Technology Solutions [Member]

Technology Solutions [Member]

Technology Solutions [Member]

Technology Solutions [Member]

Technology Solutions [Member]

Technology Solutions [Member]

Technology Solutions [Member]

Technology Solutions [Member]

Cost of Sales [Member]

Cost of Sales [Member]

Operating Expense [Member]

Operating Expense [Member]

Product Alignment [Member]

Product Alignment [Member]

Product Alignment [Member]

Product Alignment [Member]

Product Alignment [Member]

Product Alignment [Member]

Product Alignment [Member]

Product Alignment [Member]

Integration-related Expenses [Member]

Severance Charges Due to Natural Reduction in Workforce [Member]

Severance Charges Due to Reorganization [Member]

Non Cash Asset Impairment Charges [Member]

Non Cash Asset Impairment Charges [Member]

Employee Severance [Member]

Customer Allowances [Member]

Other Product Alignment Charges [Member]

Cost of Sales [Member]

Operating Expense [Member]

Asset Impairments And Product Alignment Charges [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Goodwill and Intangible Asset Impairment

'

'

'

'

$46

$57

$46

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Pre-tax charges resulting from product alignment plan

'

'

'

57

'

'

'

34

'

23

'

35

51

24

10

7

10

31

20

15

7

35

15

Asset impairment charge - capitalized software held for sale

12

10

0

'

'

'

'

'

10

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Goodwill, Impairment Loss

'

$36

'

'

$36

'

$36

'

'

'

$36

'

'

'

'

'

'

'

'

'

'

'

'

Impairment_and_Sale_of_an_Equi1

Impairment and Sale of an Equity Investment (Narrative) (Details) (USD $)	12 Months Ended			3 Months Ended	6 Months Ended	12 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013	Mar. 31, 2012	Mar. 31, 2013	Sep. 30, 2013	Mar. 31, 2013	Sep. 30, 2012
				Distribution Solutions [Member]	Distribution Solutions [Member]	Distribution Solutions [Member]	Distribution Solutions [Member]
				Nadro [Member]	Nadro [Member]	Nadro [Member]	Nadro [Member]
Schedule of Equity Method Investments [Line Items]	'	'	'	'	'	'	'
Interest in Investee	'	'	'	49.00%	49.00%	49.00%	49.00%
Impairment of an equity investment	$0	$191	$0	$191	'	$191	'
Cumulative foreign currency translation loss, before tax	'	'	'	'	'	69	'
Proceeds from Sale of Equity Method Investments	'	'	'	'	$41	'	'

ShareBased_Compensation_Narrat

Share-Based Compensation (Narrative) (Details) (USD $)

12 Months Ended

12 Months Ended

In Millions, except Share data, unless otherwise specified

Mar. 31, 2014

Mar. 31, 2014

Mar. 31, 2013

Mar. 31, 2012

Mar. 31, 2014

Mar. 31, 2013

Mar. 31, 2012

Mar. 31, 2014

Mar. 31, 2014

Mar. 31, 2014

31-May-13

Mar. 31, 2014

Mar. 31, 2013

Mar. 31, 2012

Mar. 31, 2014

Mar. 31, 2014

Stock Option [Member]

Stock Option [Member]

Stock Option [Member]

Restricted Stock Units (RSUs) [Member]

Restricted Stock Units (RSUs) [Member]

Restricted Stock Units (RSUs) [Member]

Restricted Stock Units (RSUs) [Member]

Restricted Stock Units (RSUs) [Member]

Performance Shares [Member]

Performance Shares [Member]

Employee Stock [Member]

Employee Stock [Member]

Employee Stock [Member]

2013 Stock Plan [Member]

Director [Member]

Minimum [Member]

Maximum [Member]

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Number of Shares Authorized

'

'

'

'

'

'

'

'

'

'

1,000,000

21,000,000

'

'

30,000,000

'

Number of Shares Available for Future Grant

'

'

'

'

'

'

'

'

'

'

'

5,000,000

'

'

33,600,000

'

Contractual term of stock plan, years

'

'7 years

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Vesting Period, Years

'

'4 years

'

'

'

'

'

'3 years

'4 years

'4 years

'

'

'

'

'

'

Vested and Exercisable, Shares

3,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

150,000

Total compensation cost, net of estimated forfeitures, related to unvested share-based awards not yet recognized, pre-tax

'

$29

$37

$40

$115

$128

$143

'

'

$121

'

'

'

'

'

'

Weighted-average period in years over which RSU cost is expected to be recognized

'

'1 year

'1 year

'1 year

'2 years

'2 years

'3 years

'

'

'3 years

'

'

'

'

'

'

Period to purchase a shares through payroll deductions, months

'

'

'

'

'

'

'

'

'

'

'

'3 months

'

'

'

'

Percentage of price to purchase shares through payroll deductions

'

'

'

'

'

'

'

'

'

'

'

85.00%

'

'

'

'

Percentage of deduction to purchase shares through payroll deductions

'

'

'

'

'

'

'

'

'

'

'

15.00%

'

'

'

'

Shares issued under ESPP

'

'

'

'

'

'

'

'

'

'

'

0

1,000,000

1,000,000

'

'

Allocated Share-based Compensation Expense Capitalized

$0

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

ShareBased_Compensation_Compon

Share-Based Compensation (Components of Share-Based Compensation Expense And Related Tax Benefits) (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2014		Mar. 31, 2013		Mar. 31, 2012		31-May-13
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'		'		'		'
Share-based compensation expense	$160		$167		$154		'
Tax benefit for share-based compensation expense	-55	[1]	-59	[1]	-55	[1]	'
Share-based compensation expense, net of tax	105		108		99		'
RSUs [Member]	'		'		'		'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'		'		'		'
Share-based compensation expense	88	[2]	109	[2]	97	[2]	'
PeRSUs [Member]	'		'		'		'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'		'		'		'
Number of Shares Authorized	'		'		'		1
Share-based compensation expense	38	[3]	23	[3]	24	[3]	'
Stock options [Member]	'		'		'		'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'		'		'		'
Share-based compensation expense	22		24		23		'
Employee stock purchase plan [Member]	'		'		'		'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'		'		'		'
Number of Shares Authorized	21		'		'		'
Share-based compensation expense	$12		$11		$10		'
2013 Stock Plan [Member]	'		'		'		'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'		'		'		'
Number of Shares Authorized	30		'		'		'
[1]	Income tax benefit is computed using the tax rates of applicable tax jurisdictions. Additionally, a portion of pre-tax compensation expense is not tax-deductible.
[2]	This expense was primarily the result of PeRSUs awarded in prior years, which converted to RSUs due to the attainment of goals during the applicable yearsb performance period.
[3]	Represents estimated compensation expense for PeRSUs that are conditional upon attaining performance objectives during the current yearbs performance period.

ShareBased_Compensation_Schedu

Share-Based Compensation (Schedule of Weighted Average Assumptions Used to Estimate the Fair Value of Employee Stock Options ) (Details)	12 Months Ended
	Mar. 31, 2014	Mar. 31, 2013	Mar. 31, 2012
Share-based Compensation [Abstract]	'	'	'
Expected Stock Price Volatility Rate	22.00%	27.00%	27.00%
Expected Dividend Yield	0.70%	0.90%	1.00%
Risk Free Interest Rate	0.70%	0.80%	2.10%
Expected Life (in Years)	'4 years	'5 years	'5 years

ShareBased_Compensation_Summar

Share-Based Compensation (Summary of Options Outstanding) (Details) (USD $)	12 Months Ended
In Millions, except Per Share data, unless otherwise specified	Mar. 31, 2014
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]	'
Number of Options Outstanding at Year End	6
Number of Options Exercisable at Year End	3
$35.53 - $69.00 [Member]	'
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]	'
Range of Exercise Prices, Lower Limit	$35.53
Range of Exercise Price, Upper Limit	$69
Number of Options Outstanding at Year End	3
Weighted-Average Remaining Contractual Life	'2 years
Weighted-Average Exercise Price	$55.70
Number of Options Exercisable at Year End	2
Weighted-Average Exercise Price	$53.76
$69.01 - $169.44 [Member]	'
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]	'
Range of Exercise Prices, Lower Limit	$69.01
Range of Exercise Price, Upper Limit	$169.44
Number of Options Outstanding at Year End	3
Weighted-Average Remaining Contractual Life	'5 years
Weighted-Average Exercise Price	$96.35
Number of Options Exercisable at Year End	1
Weighted-Average Exercise Price	$84.81

ShareBased_Compensation_Stock_

Share-Based Compensation (Stock Option Activity) (Details) (USD $)	12 Months Ended
In Millions, except Per Share data, unless otherwise specified	Mar. 31, 2014		Mar. 31, 2013
Share-based Compensation [Abstract]	'		'
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Number	6		7
Granted, Shares	1		'
Exercised, Shares	-2		'
Vested and Expected to Vest, Shares	5	[1]	'
Vested and Exercisable, Shares	3		'
Outstanding, Weighted-Average Exercise Price, Beginning of Period	$65.79		'
Granted, Weighted-Average Exercise Price	$120.79		'
Exercised, Weighted-Average Exercise Price	$56.74		'
Outstanding, Weighted-Average Exercise Price, End of Period	$78.07		$65.79
Vested and Expected to Vest, Weighted-Average Exercise Price	$77.27	[1]	'
Vested and Exercisable, Weighted-Average Exercise Price	$61.07		'
Outstanding, Weighted-Average Remaining Contractual Term, Beginning of Period, Years	'4 years		'4 years
Outstanding, Weighted-Average Remaining Contractual Term, End of Period, Years	'4 years		'4 years
Vested and Expected to Vest, Weighted-Average Remaining Contractual Term, Years	'4 years	[1]	'
Vested and Exercisable, Weighted-Average Remaining Contractual Term, Years	'3 years		'
Outstanding, Aggregate Intrinsic Value, Beginning of Period	$260	[2]	'
Outstanding, Aggregate Intrinsic Value, End of Period	473	[2]	260	[2]
Vested and Expected to Vest, Aggregate Intrinsic Value	472	[1],[2]	'
Vested and Exercisable, Aggregate Intrinsic Value	$281	[2]	'
[1]	The number of options expected to vest takes into account an estimate of expected forfeitures.
[2]	The intrinsic value is calculated as the difference between the period-end market price of the Companybs common stock and the exercise price of bin-the-moneyb options.

ShareBased_Compensation_Data_R

Share-Based Compensation (Data Related to Stock Option Activity) (Details) (USD $)	12 Months Ended
In Millions, except Per Share data, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013	Mar. 31, 2012
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Number	6	7	'
Stock Option [Member]	'	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'
Weighted-average grant date fair value per stock option	$21.45	$19.63	$20.32
Aggregate intrinsic value on exercise	$144	$107	$108
Cash received upon exercise	111	106	113
Tax benefits realized related to exercise	55	41	40
Total fair value of shares vested	24	24	23
Total compensation cost, net of estimated forfeitures, related to unvested share-based awards not yet recognized, pre-tax	$29	$37	$40
Weighted-average period in years over which stock option compensation is expected to be recognized	'1 year	'1 year	'1 year

ShareBased_Compensation_RSU_Ac

Share-Based Compensation (RSU Activity) (Details) (Restricted Stock Units (RSUs) [Member], USD $)	12 Months Ended
In Millions, except Per Share data, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013
Restricted Stock Units (RSUs) [Member]	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number	4	6
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value	$93.25	$76.20
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period	1	'
Weighted-average grant date fair value per stock option	$120.63	'
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period	-3	'
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value	$67.32	'

ShareBased_Compensation_Data_R1

Share-Based Compensation (Data Related to RSU Activity) (Details) (Restricted Stock Units (RSUs) [Member], USD $)	12 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013	Mar. 31, 2012
Restricted Stock Units (RSUs) [Member]	'	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period, Fair Value	$184	$66	$44
Total compensation cost, net of estimated forfeitures, related to nonvested RSU awards not yet recognized, pre-tax	$115	$128	$143
Weighted-average period in years over which RSU cost is expected to be recognized	'2 years	'2 years	'3 years

Other_Income_Expense_Net_Summa

Other Income (Expense), Net (Summary of Other Income (Expense), Net) (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2014		Mar. 31, 2013		Mar. 31, 2012
Other Nonoperating Income (Expense) [Abstract]	'		'		'
Interest income	$23		$22		$19
Equity in earnings (loss), net (1)	-3	[1]	3	[1]	9	[1]
Other, net	12		9		-8
Total	$32		$34		$20
[1]	Primarily recorded within our Distribution Solutions segment.

Income_Taxes_Narrative_Details

Income Taxes (Narrative) (Details) (USD $)

12 Months Ended

12 Months Ended

3 Months Ended

9 Months Ended

12 Months Ended

Mar. 31, 2014

Mar. 31, 2013

Mar. 31, 2012

Mar. 31, 2011

Mar. 31, 2014

Dec. 31, 2013

Dec. 31, 2013

Mar. 31, 2014

Mar. 31, 2014

Mar. 31, 2014

Mar. 31, 2014

Mar. 31, 2012

Internal Revenue Service (IRS) [Member]

Canada Revenue Agency Assessments [Member]

Canada Revenue Agency Assessments [Member]

State and Local Jurisdiction [Member]

Domestic Tax Authority [Member]

Foreign Tax Authority [Member]

Foreign Tax Authority [Member]

Average Wholesale Price Litigation [Member]

Research Tax Credit Carryforward [Member]

Income Tax [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

Income Tax Expense Discrete Items

($94,000,000)

$29,000,000

$66,000,000

'

'

$122,000,000

'

'

'

'

'

$31,000,000

Tax assessments received relating to transfer pricing issues

'

'

'

'

98,000,000

'

219,000,000

'

'

'

'

'

Undistributed Earnings of Foreign Operations

4,200,000,000

'

'

'

'

'

'

'

'

'

'

'

Federal, State and Foreign Operating Loss Carryforwards

'

'

'

'

'

'

'

2,524,000,000

53,000,000

935,000,000

'

'

Canadian research and development carryforwards

'

'

'

'

'

'

'

'

'

'

11,000,000

'

Unrecognized Tax Benefits

647,000,000

560,000,000

595,000,000

635,000,000

'

'

'

'

'

'

'

'

Unrecognized Tax Benefits that would Impact Income Tax Expense and the Effective Tax Rate

490,000,000

'

'

'

'

'

'

'

'

'

'

'

Potential Reduction of Unrecognized Benefits Due to Audit Resolutions and Expiration of Statutes of Limitations

230,000,000

'

'

'

'

'

'

'

'

'

'

'

Income Tax Expense, Before Any Tax Effect, Related to Accrued Interest Expense

48,000,000

'

'

'

'

'

'

'

'

'

'

'

Effective Income Tax Rate Reconciliation, Foreign Income Tax Rate Differential, Amount

8,000,000

'

'

'

'

'

'

'

'

'

'

'

Accrued interest and penalties on unrecognized tax benefits

179,000,000

131,000,000

'

'

'

'

'

'

'

'

'

'

Deferred Tax Liabilities, Undistributed Foreign Earnings

$0

'

'

'

'

'

'

'

'

'

'

'

Income_Taxes_Income_Before_Inc

Income Taxes (Income Before Income Taxes From Continuing Operations) (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013	Mar. 31, 2012
Income Tax Disclosure [Abstract]	'	'	'
U.S.	$1,554	$1,562	$1,293
Foreign	542	366	600
Income from Continuing Operations Before Income Taxes	$2,096	$1,928	$1,893

Income_Taxes_Components_Of_Pro

Income Taxes (Components Of Provision For Income Taxes Related To Continuing Operations) (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013	Mar. 31, 2012
Income Tax Disclosure [Abstract]	'	'	'
Federal	$484	($84)	$265
State and local	64	14	51
Foreign	178	40	28
Total current	726	-30	344
Federal	24	538	132
State and local	10	80	29
Foreign	-18	-7	9
Total deferred	16	611	170
Income tax provision	$742	$581	$514

Income_Taxes_Reconciliation_Be

Income Taxes (Reconciliation Between Effective Tax Rate On Income From Continuing Operations And Statutory Tax Rate) (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013	Mar. 31, 2012
Income Tax Disclosure [Abstract]	'	'	'
Income tax provision at federal statutory rate	$734	$670	$670
State and local income taxes net of federal tax benefit	57	58	56
Foreign income taxed at various rates	-166	-136	-174
Canadian litigation	122	0	0
Unrecognized tax benefits and settlements	-6	1	-18
Tax credits	-6	-13	-13
Other, net	7	1	-7
Income tax provision	$742	$581	$514

Income_Taxes_Components_Of_Def

Income Taxes (Components Of Deferred Tax Balances) (Details) (USD $)	Mar. 31, 2014	Mar. 31, 2013
In Millions, unless otherwise specified
Income Tax Disclosure [Abstract]	'	'
Receivable allowances	$106	$84
Deferred revenue	136	106
Compensation and benefit related accruals	641	553
Loss and credit carryforwards	430	341
Other	289	281
Subtotal	1,602	1,365
Less: valuation allowance	-270	-118
Total assets	1,332	1,247
Inventory valuation and other assets	-2,163	-2,089
Fixed assets and systems development costs	-321	-267
Intangibles	-1,531	-734
Other	-118	-24
Total liabilities	-4,133	-3,114
Current net deferred tax asset	51	16
Current net deferred tax liability	-1,588	-1,626
Long-term deferred tax asset	19	21
Long-term deferred tax liability	-1,283	-278
Net deferred tax liability	($2,801)	($1,867)

Income_Taxes_Gross_Unrecognize

Income Taxes (Gross Unrecognized Tax Benefits) (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013	Mar. 31, 2012
Income Tax Disclosure [Abstract]	'	'	'
Unrecognized tax benefits at period start	$560	$595	$635
Additions based on tax positions related to prior years	106	46	11
Reductions based on tax positions related to prior years	-31	-108	-72
Additions based on tax positions related to current year	23	31	37
Reductions based on settlements	-4	-2	-1
Reductions based on the lapse of the applicable statutes of limitations	-7	-2	-15
Unrecognized tax benefits at period end	$647	$560	$595

Earnings_Per_Common_Share_Narr

Earnings Per Common Share (Narrative) (Details)	12 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013	Mar. 31, 2012
Earnings Per Share [Abstract]	'	'	'
Potentially dilutive shares excluded from diluted earnings per share	2	2	4

Earnings_Per_Common_Share_Basi

Earnings Per Common Share (Basic and Diluted Earnings per Common Share) (Details) (USD $)

3 Months Ended

12 Months Ended

In Millions, except Per Share data, unless otherwise specified

Mar. 31, 2014

Dec. 31, 2013

Sep. 30, 2013

Jun. 30, 2013

Mar. 31, 2013

Dec. 31, 2012

Sep. 30, 2012

Jun. 30, 2012

Mar. 31, 2014

Mar. 31, 2013

Mar. 31, 2012

Earnings Per Share, Basic and Diluted, by Common Class [Line Items]

'

'

'

'

'

'

'

'

'

'

'

Income from continuing operations

$362

[1],[2]

$156

[1],[2]

$416

[1],[2]

$420

[1],[2]

$263

[3],[4],[5]

$306

[3],[4],[5]

$399

[3],[4],[5]

$379

[3],[4],[5]

$1,354

$1,347

$1,379

Net loss attributable to noncontrolling interests

5

[6]

0

[6]

0

[6]

0

[6]

0

0

0

0

5

0

0

Income from continuing operations attributable to McKesson

'

'

'

'

'

'

'

'

1,359

1,347

1,379

Income (Loss) from Discontinued Operations, Net of Tax

4

[7]

-92

[7]

-12

[7]

4

[7]

-4

-8

2

1

-96

-9

24

Net income attributable to McKesson

$371

$64

$404

$424

$259

$298

$401

$380

$1,263

$1,338

$1,403

Weighted average common shares outstanding:

'

'

'

'

'

'

'

'

'

'

'

Basic

'

'

'

'

'

'

'

'

229

235

246

Effect of dilutive securities:

'

'

'

'

'

'

'

'

'

'

'

Diluted

'

'

'

'

'

'

'

'

233

239

251

Diluted

'

'

'

'

'

'

'

'

'

'

'

Continuing operations

$1.56

$0.67

$1.79

$1.81

$1.11

$1.27

$1.66

$1.58

$5.83

[8]

$5.62

[8]

$5.49

[8]

Discontinued operations

$0.02

($0.39)

($0.05)

$0.02

($0.01)

($0.03)

$0.01

$0

($0.42)

[8]

($0.03)

[8]

$0.10

[8]

Total

$1.58

$0.28

$1.74

$1.83

$1.10

$1.24

$1.67

$1.58

$5.41

[8]

$5.59

[8]

$5.59

[8]

Basic

'

'

'

'

'

'

'

'

'

'

'

Continuing operations

$1.59

$0.68

$1.82

$1.84

$1.13

$1.30

$1.69

$1.61

$5.93

[8]

$5.74

[8]

$5.60

[8]

Discontinued operations

$0.02

($0.40)

($0.06)

$0.02

($0.01)

($0.03)

$0.01

$0

($0.42)

[8]

($0.03)

[8]

$0.10

[8]

Total

$1.61

$0.28

$1.76

$1.86

$1.12

$1.27

$1.70

$1.61

$5.51

[8]

$5.71

[8]

$5.70

[8]

Stock options [Member]

'

'

'

'

'

'

'

'

'

'

'

Effect of dilutive securities:

'

'

'

'

'

'

'

'

'

'

'

Dilutive securities

'

'

'

'

'

'

'

'

1

1

2

Restricted Stock Units (RSUs) [Member]

'

'

'

'

'

'

'

'

'

'

'

Effect of dilutive securities:

'

'

'

'

'

'

'

'

'

'

'

Dilutive securities

'

'

'

'

'

'

'

'

3

3

3

[1]

Financial results for the third quarter of 2014 include an income tax charge of $122 million relating to a litigation with the Canadian Revenue Agency.

[2]

Financial results for the second, third and fourth quarters of 2014 includes pre-tax charges in our Distribution Solutions segment related to our LIFO method of accounting for inventories of $44 million, $142 million and $125B million, which were recorded in cost of sales. Fourth quarter 2014 also includes a $50B million pre-tax charge to cost of sales within our Distribution Solutions segment representing the reversal of a step-up to fair value of Celesiobs inventory at the date of acquisition. Our after-tax portion of this charge (after allocation to noncontrolling interests), was $28 million

[3]

Financial results for the first quarter of 2013 include an $81 million pre-tax gain on business combination, which was recorded as a reduction to operating expenses within our Corporate segment.

[4]

Financial results for the fourth quarter of 2013 include a pre-tax impairment charge for an equity investment of $191 million recorded in other income, net within our Distribution Solutions segment. Financial results for the fourth quarter of 2013 also include $46 million of pre-tax impairment charges recorded in our Technology Solutions segment of which $36 million was recorded in operating expenses and $10B million was recorded in cost of sales.

[5]

Financial results for the third quarter of 2013 include a $40 million pre-tax charge for a legal dispute in our Canadian business which was recorded in operating expenses within our Distribution Solutions segment.

[6]

Primarily represents the noncontrolling shareholdersb portion of net loss from Celesio.

[7]

Financial results for the third quarter of 2014, include an $80 million of after-tax impairment charge related to our International Technology Business.

[8]

Certain computations may reflect rounding adjustments.

Receivables_Net_Schedule_of_Ac

Receivables, Net (Schedule of Accounts Receivable) (Details) (USD $)	Mar. 31, 2014	Mar. 31, 2013
In Millions, unless otherwise specified
Receivables, Net, Current [Abstract]	'	'
Customer accounts	$12,543	$8,683
Other	1,780	1,423
Total	14,323	10,106
Allowances	-130	-131
Net	$14,193	$9,975

Property_Plant_and_Equipment_N2

Property, Plant and Equipment, Net (Schedule Of Property, Plant And Equipment, Net) (Details) (USD $)	Mar. 31, 2014	Mar. 31, 2013
In Millions, unless otherwise specified
Property, Plant and Equipment, Net [Abstract]	'	'
Land	$221	$129
Building, machinery, equipment and other	3,180	2,400
Total property, plant and equipment	3,401	2,529
Accumulated depreciation	-1,179	-1,208
Property, plant and equipment, net	$2,222	$1,321

Goodwill_and_Intangible_Assets2

Goodwill and Intangible Assets, Net (Narrative - Goodwill) (Details) (Technology Solutions [Member], USD $)	Mar. 31, 2014	Mar. 31, 2013
In Millions, unless otherwise specified
Technology Solutions [Member]	'	'
Goodwill [Line Items]	'	'
Goodwill, Impaired, Accumulated Impairment Loss	$36	$36

Goodwill_and_Intangible_Assets3

Goodwill and Intangible Assets, Net (Narrative - Intangible Assets) (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013	Mar. 31, 2012
Goodwill and Intangible Assets Disclosure [Abstract]	'	'	'
Amortization Expense of Intangible Assets	$319	$215	$191
Annual Amortization Expense, 2015	469	'	'
Annual Amortization Expense, 2016	509	'	'
Annual Amortization Expense, 2017	465	'	'
Annual Amortization Expense, 2018	461	'	'
Annual Amortization Expense, 2019	445	'	'
Annual Amortization Expense, After 2019	$2,673	'	'

Goodwill_and_Intangible_Assets4

Goodwill and Intangible Assets, Net (Changes In The Carrying Amount Of Goodwill) (Details) (USD $)	3 Months Ended	12 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2013	Mar. 31, 2014	Mar. 31, 2013
Goodwill [Line Items]	'	'	'
Goodwill, Beginning balance	'	$6,405	$5,032
Goodwill, Acquired During Period	'	3,649	1,421
Amount reclassified to assets held-for-sale	'	-128	'
Goodwill, Impairment Loss	'	'	-36
Acquisition Accounting and Other Adjustments	'	1	5
Foreign Currency Translation Adjustments	'	0	-17
Goodwill, Ending balance	6,405	9,927	6,405
Distribution Solutions [Member]	'	'	'
Goodwill [Line Items]	'	'	'
Goodwill, Beginning balance	'	4,413	3,190
Goodwill, Acquired During Period	'	3,649	1,228
Amount reclassified to assets held-for-sale	'	-1	'
Goodwill, Impairment Loss	'	'	0
Acquisition Accounting and Other Adjustments	'	13	6
Foreign Currency Translation Adjustments	'	4	-11
Goodwill, Ending balance	4,413	8,078	4,413
Technology Solutions [Member]	'	'	'
Goodwill [Line Items]	'	'	'
Goodwill, Beginning balance	'	1,992	1,842
Goodwill, Acquired During Period	'	0	193
Amount reclassified to assets held-for-sale	'	-127	'
Goodwill, Impairment Loss	-36	'	-36
Acquisition Accounting and Other Adjustments	'	-12	-1
Foreign Currency Translation Adjustments	'	-4	-6
Goodwill, Ending balance	$1,992	$1,849	$1,992

Goodwill_and_Intangible_Assets5

Goodwill and Intangible Assets, Net (Information Regarding Intangible Assets) (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013
Intangible assets	'	'
Gross Carrying Amount	$6,353	$3,347
Accumulated Amortization	-1,331	-1,077
Net Carrying Amount	5,022	2,270
Customer Lists [Member]	'	'
Intangible assets	'	'
Weighted Average Remaining Amortization Period (years)	'10 years	'
Gross Carrying Amount	3,384	1,761
Accumulated Amortization	-863	-672
Net Carrying Amount	2,521	1,089
Service Agreements [Member]	'	'
Intangible assets	'	'
Weighted Average Remaining Amortization Period (years)	'16 years	'
Gross Carrying Amount	995	1,018
Accumulated Amortization	-173	-114
Net Carrying Amount	822	904
Pharmacy Licenses [Member]	'	'
Intangible assets	'	'
Weighted Average Remaining Amortization Period (years)	'26 years	'
Gross Carrying Amount	1,219	0
Accumulated Amortization	-11	0
Net Carrying Amount	1,208	0
Trademarks and Trade Names [Member]	'	'
Intangible assets	'	'
Weighted Average Remaining Amortization Period (years)	'15 years	'
Gross Carrying Amount	371	208
Accumulated Amortization	-59	-46
Net Carrying Amount	312	162
Technology [Member]	'	'
Intangible assets	'	'
Weighted Average Remaining Amortization Period (years)	'3 years	'
Gross Carrying Amount	219	271
Accumulated Amortization	-173	-207
Net Carrying Amount	46	64
Other Intangible Assets [Member]	'	'
Intangible assets	'	'
Weighted Average Remaining Amortization Period (years)	'5 years	'
Gross Carrying Amount	165	89
Accumulated Amortization	-52	-38
Net Carrying Amount	$113	$51

Capitalized_Software_Held_for_2

Capitalized Software Held for Sale (Narrative) (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013	Mar. 31, 2012
Capitalized Computer Software, Net [Abstract]	'	'	'
Royalty Expense	$91	$88	$95

Capitalized_Software_Held_for_3

Capitalized Software Held for Sale (Changes in the Carrying Amount) (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013	Mar. 31, 2012
Capitalized Computer Software, Net [Abstract]	'	'	'
Capitalized software held for sale, net at beginning of period	$126	$144	$152
Amounts capitalized	40	49	47
Amortization expense	-50	-56	-53
Impairment charges	-12	-10	0
Foreign currency translations adjustments, net	-1	-1	-2
Capitalized software held for sale, net at end of period	$103	$126	$144

Recovered_Sheet1

Debt And Financing Activities (Senior Bridge Term Loan Facility) (Narrative) (Details)

12 Months Ended

0 Months Ended

1 Months Ended

12 Months Ended

3 Months Ended

12 Months Ended

1 Months Ended

1 Months Ended

3 Months Ended

Share data in Millions, unless otherwise specified

Mar. 31, 2014

Mar. 31, 2013

Mar. 31, 2012

Mar. 31, 2014

Mar. 31, 2013

Mar. 31, 2012

Feb. 06, 2014

Mar. 31, 2014

Mar. 31, 2013

Feb. 04, 2014

Mar. 31, 2014

Mar. 31, 2014

Mar. 31, 2014

Mar. 31, 2013

Mar. 31, 2014

Mar. 31, 2013

Mar. 08, 2013

Mar. 31, 2013

Mar. 31, 2013

Feb. 28, 2013

Feb. 22, 2013

Dec. 31, 2012

Jan. 31, 2014

Jan. 31, 2014

Mar. 31, 2013

Nov. 30, 2013

Oct. 31, 2013

Mar. 31, 2014

Mar. 31, 2014

USD ($)

USD ($)

USD ($)

Corporate [Member]

Corporate [Member]

Corporate [Member]

Celesio [Member]

Celesio [Member]

Celesio [Member]

Celesio [Member]

Celesio [Member]

Celesio [Member]

Celesio [Member]

Celesio [Member]

Celesio [Member]

Celesio [Member]

PSS World Medical [Member]

PSS World Medical [Member]

PSS World Medical [Member]

PSS World Medical [Member]

PSS World Medical [Member]

PSS World Medical [Member]

Senior Bridge Term Loan Agreement, 2013 [Member]

Senior Bridge Term Loan Agreement, 2013 [Member]

Revolving Credit Facility [Member]

Revolving Credit Facility [Member]

Revolving Credit Facility [Member]

Revolving Credit Facility [Member]

Private Purchases [Member]

USD ($)

USD ($)

USD ($)

USD ($)

Promissory Notes [Member]

Promissory Notes [Member]

Senior Bridge Term Loan Agreement, 2014 [Member]

Senior Bridge Term Loan Agreement, 2014 [Member]

Senior Bridge Term Loan Agreement, 2014 [Member]

4.00 % Bonds Due October 18, 2016 [Member]

4.00 % Bonds Due October 18, 2016 [Member]

4.50% Bonds Due April 26, 2017 [Member]

4.50% Bonds Due April 26, 2017 [Member]

Bridge Loan [Member]

Bridge Loan [Member]

Bridge Loan [Member]

Senior Bridge Term Loan Agreement, 2013 [Member]

Senior Bridge Term Loan Agreement, 2013 [Member]

Senior Bridge Term Loan Agreement, 2013 [Member]

Celesio [Member]

Celesio [Member]

USD ($)

Maximum [Member]

Maximum [Member]

Celesio [Member]

Celesio [Member]

USD ($)

USD ($)

USD ($)

USD ($)

Corporate [Member]

USD ($)

USD ($)

USD ($)

USD ($)

USD ($)

Corporate [Member]

USD ($)

USD ($)

USD ($)

Bridge Loan [Member]

EUR (€)

USD ($)

USD ($)

USD ($)

Debt Instrument [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Credit facility

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

$900,000,000

$2,100,000,000

'

$5,500,000,000

'

'

'

€ 500,000,000

'

Debt Instrument, Term

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'364 days

'

'

'

'

'

'

Repayments of Short-term Debt

6,122,000,000

2,625,000,000

0

'

'

'

'

'

'

'

4,076,000,000

'

'

'

'

'

900,000,000

'

'

'

'

'

'

'

'

'

'

'

'

Proceeds from Bridge Loan

6,145,000,000

2,225,000,000

400,000,000

'

'

'

'

'

'

4,957,000,000

'

'

'

'

'

'

'

'

'

900,000,000

'

'

'

'

'

'

'

'

'

Bridge loan interest rate

'

'

'

'

'

'

'

'

'

'

1.39%

'

'

'

'

'

'

1.20%

'

'

'

'

'

'

'

'

'

'

'

Interest expense: bridge loan fees

'

'

'

46,000,000

11,000,000

0

'

'

'

'

'

46,000,000

'

'

'

'

'

'

11,000,000

'

'

'

'

'

'

'

'

'

'

Borrowings Outstanding

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

0

'

'

'

'

Debt Conversion, Converted Instrument, Shares Issued

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

0.7

Long-term debt

10,373,000,000

4,873,000,000

'

'

'

'

'

'

'

'

'

'

507,000,000

0

737,000,000

0

'

'

'

'

'

'

'

'

'

'

'

'

'

Ratio of Indebtedness to Net Capital

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

0.65

0.565

'

'

Bilateral credit line

'

'

'

'

'

'

1,662,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Other long-term debt

'

'

'

'

'

'

'

$297,000,000

$0

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Debt_and_Financing_Activities_1

Debt and Financing Activities (PSS World Medical Debt Acquired) (Narrative) (Details) (PSS World Medical [Member], USD $)	1 Months Ended		3 Months Ended
In Millions, unless otherwise specified	Feb. 28, 2013	Feb. 28, 2013	Mar. 31, 2013
	Senior Notes Due 2022 [Member]	Senior Convertible Notes Due 2014 [Member]	Senior Notes Due 2022 And Senior Convertible Notes Due 2014 [Member]
Debt Instrument [Line Items]	'	'	'
Interest rate on debt	6.38%	3.13%	'
Debt Instrument, Maturity Date	1-Mar-22	1-Aug-14	'
Payoff of PSS World Medical Debt	'	'	$643

Debt_and_Financing_Activities_2

Debt and Financing Activities (Long-Term Debt) (Narrative) (Details) (USD $)

1 Months Ended

3 Months Ended

12 Months Ended

12 Months Ended

1 Months Ended

12 Months Ended

1 Months Ended

12 Months Ended

1 Months Ended

12 Months Ended

1 Months Ended

12 Months Ended

1 Months Ended

0 Months Ended

12 Months Ended

2 Months Ended

In Millions, unless otherwise specified

Mar. 31, 2014

Mar. 31, 2014

Mar. 31, 2014

Mar. 31, 2013

Mar. 31, 2012

Mar. 05, 2014

Mar. 31, 2014

Mar. 31, 2013

Mar. 05, 2014

Mar. 05, 2014

Mar. 05, 2014

Mar. 05, 2014

Mar. 31, 2013

Mar. 31, 2014

Mar. 31, 2013

Mar. 08, 2013

Mar. 31, 2013

Mar. 31, 2014

Mar. 31, 2013

Mar. 08, 2013

Mar. 31, 2013

Dec. 31, 2012

Mar. 31, 2014

Mar. 31, 2013

Dec. 04, 2012

Dec. 31, 2012

Mar. 31, 2014

Mar. 31, 2013

Dec. 04, 2012

Dec. 31, 2012

Feb. 15, 2014

Mar. 31, 2014

Mar. 31, 2013

Mar. 01, 2013

Mar. 31, 2014

D

Floating Rate Notes Due September 10, 2015 [Member]

1.29 % Notes Due March 10, 2017 [Member]

1.29 % Notes Due March 10, 2017 [Member]

1.29 % Notes Due March 10, 2017 [Member]

2.28% Notes Due March 15, 2019 [Member]

3.80% Notes Due March 15, 2024 [Member]

4.88 % Notes Due March 15, 2044 [Member]

1.40% Notes Due March 15, 2018 [Member]

1.40% Notes Due March 15, 2018 [Member]

1.40% Notes Due March 15, 2018 [Member]

1.40% Notes Due March 15, 2018 [Member]

2.85% Notes Due March 15, 2023 [Member]

2.85% Notes Due March 15, 2023 [Member]

2.85% Notes Due March 15, 2023 [Member]

2.85% Notes Due March 15, 2023 [Member]

1.40% Notes Due March 15, 2018 And 2.85% Notes Due March 15, 2023 [Member]

0.95% Notes Due December 4, 2015 [Member]

0.95% Notes Due December 4, 2015 [Member]

0.95% Notes Due December 4, 2015 [Member]

0.95% Notes Due December 4, 2015 [Member]

2.70% Notes Due December 15, 2022 [Member]

2.70% Notes Due December 15, 2022 [Member]

2.70% Notes Due December 15, 2022 [Member]

2.70% Notes Due December 15, 2022 [Member]

0.95% Notes Due December 4, 2015 And 2.70% Notes Due December 15, 2022 [Member]

6.50% Notes Due February 15, 2014 [Member]

6.50% Notes Due February 15, 2014 [Member]

6.50% Notes Due February 15, 2014 [Member]

Five Point Two Five Percent Notes Due March One Two Thousand Thirteen [Member]

London Interbank Offered Rate (LIBOR) [Member]

Debt Instrument [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Debt Instrument, Maturity Date

'

'

'

'

'

'

10-Mar-17

10-Mar-17

'

'

'

'

15-Mar-18

15-Mar-18

15-Mar-18

'

15-Mar-23

15-Mar-23

15-Mar-23

'

'

4-Dec-15

4-Dec-15

4-Dec-15

'

15-Dec-22

15-Dec-22

15-Dec-22

'

'

'

15-Feb-14

15-Feb-14

'

'

Debt Instrument, Face Amount

'

'

'

'

'

$400

'

'

$700

$1,100

$1,100

$800

'

'

'

$500

'

'

'

$400

'

'

'

'

$500

'

'

'

$400

'

'

'

'

'

'

Long-term Debt, Percentage Bearing Variable Interest, Percentage Rate

0.64%

0.64%

0.64%

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

0.40%

Debt Instrument, Date of First Required Payment

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

15-Sep-13

4-Jun-13

'

'

'

15-Jun-13

'

'

'

'

'

'

'

'

'

Proceeds from issuances of long-term debt

4,068

'

4,114

1,798

0

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

891

'

'

'

'

'

'

'

'

892

'

'

'

'

'

Number Of Days Notice Before Notes Can Be Redeemed

'

30

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Contingent purchase offer, Series

'

101.00%

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Repayments of Other Short-term Debt

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

350

'

'

'

'

Amount repaid

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

500

'

Future principal payments of long-term debt in 2015

1,424

1,424

1,424

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Future principal payments of long-term debt in 2016

1,535

1,535

1,535

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Future principal payments of long-term debt in 2017

1,277

1,277

1,277

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Future principal payments of long-term debt in 2018

520

520

520

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Future principal payments of long-term debt in 2019

1,485

1,485

1,485

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Future principal payments of long-term debt, thereafter

$4,132

$4,132

$4,132

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Interest rate on debt

'

'

'

'

'

'

1.29%

1.29%

1.29%

2.28%

3.80%

4.88%

1.40%

1.40%

1.40%

1.40%

2.85%

2.85%

2.85%

2.85%

'

'

0.95%

0.95%

0.95%

'

2.70%

2.70%

2.70%

'

6.50%

6.50%

6.50%

5.25%

'

Recovered_Sheet2

Debt And Financing Activities (Accounts Receivable Sales Facility, Revolving Credit Facility and Commercial Paper) (Narrative) (Details)

12 Months Ended

1 Months Ended

12 Months Ended

9 Months Ended

12 Months Ended

2 Months Ended

12 Months Ended

Mar. 31, 2014

Mar. 31, 2013

Mar. 31, 2012

Nov. 30, 2013

Mar. 31, 2014

Mar. 31, 2013

Mar. 31, 2012

Nov. 30, 2013

Oct. 31, 2013

Dec. 31, 2013

Mar. 31, 2014

Mar. 31, 2013

Mar. 31, 2012

Nov. 30, 2013

Oct. 31, 2013

Mar. 31, 2014

Mar. 31, 2014

Feb. 06, 2014

Mar. 31, 2014

Mar. 31, 2014

Mar. 31, 2013

Mar. 31, 2014

Mar. 31, 2013

USD ($)

USD ($)

USD ($)

Accounts Receivable Sales Facility [Member]

Accounts Receivable Sales Facility [Member]

Accounts Receivable Sales Facility [Member]

Accounts Receivable Sales Facility [Member]

Accounts Receivable Sales Facility [Member]

Accounts Receivable Sales Facility [Member]

Revolving Credit Facility [Member]

Revolving Credit Facility [Member]

Revolving Credit Facility [Member]

Revolving Credit Facility [Member]

Revolving Credit Facility [Member]

Revolving Credit Facility [Member]

Revolving Credit Facility Due September Two Thousand Sixteen [Member]

Celesio [Member]

Celesio [Member]

Celesio [Member]

Celesio [Member]

Celesio [Member]

Celesio [Member]

Celesio [Member]

USD ($)

USD ($)

USD ($)

Maximum [Member]

Maximum [Member]

USD ($)

USD ($)

USD ($)

Maximum [Member]

Maximum [Member]

Unsecured Debt [Member]

Accounts Receivable Sales Facility [Member]

Accounts Receivable Sales Facility [Member]

Revolving Credit Facility [Member]

4.00 % Bonds Due October 18, 2016 [Member]

4.00 % Bonds Due October 18, 2016 [Member]

4.50% Bonds Due April 26, 2017 [Member]

4.50% Bonds Due April 26, 2017 [Member]

Revolving Credit Facility [Member]

USD ($)

USD ($)

EUR (€)

USD ($)

Line of Credit Facility [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Interest rate on debt

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

4.00%

4.00%

4.50%

4.50%

Debt Instrument, Maturity Date

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

18-Oct-16

18-Oct-16

26-Apr-17

26-Apr-17

Repayments of Short-term Debt

$6,122,000,000

$2,625,000,000

$0

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Line of Credit Facility, Expiration Period

'

'

'

'1 year

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Ratio of Indebtedness to Net Capital

'

'

'

'

'

'

'

0.65

0.565

'

'

'

'

0.65

0.565

'

'

'

'

'

'

'

'

Credit facility

'

'

'

'

1,350,000,000

'

'

'

'

'

'

'

'

'

'

'

'

308,000,000

500,000,000

'

'

'

'

Facility Expiration Date

'

'

'

'

'

'

'

'

'

23-Sep-16

'

'

'

'

'

'

'

'

'

'

'

'

'

Proceeds from Lines of Credit

'

'

'

'

550,000,000

1,325,000,000

400,000,000

'

'

'

0

0

0

'

'

'

570,000,000

'

'

'

'

'

'

Borrowings Outstanding

'

'

'

'

'

'

'

'

'

'

'

0

'

'

'

0

'

'

'

'

'

'

'

Repayments of Lines of Credit

'

'

'

'

550,000,000

1,725,000,000

0

'

'

'

'

'

'

'

'

'

575,000,000

'

'

'

'

'

'

Pledged Assets, Not Separately Reported, Finance Receivables

'

'

'

'

0

0

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Unsecured Debt

'

'

'

'

'

'

'

'

'

'

1,300,000,000

'

'

'

'

'

'

'

'

'

'

'

'

Delinquency Ratio For Qualifying Receivables

'

'

'

'

'

'less than 1%

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Issuance of commercial paper

0

0

0

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Commercial paper amount outstanding

$0

$0

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Recovered_Sheet3

Debt And Financing Activities (Debt Covenants) (Narrative) (Details) (USD $)	Mar. 31, 2014	Mar. 31, 2014	Nov. 30, 2013	Oct. 31, 2013	Nov. 30, 2013	Oct. 31, 2013
	Revolving Credit Facility [Member]	Accounts Receivable Sales Facility [Member]	Maximum [Member]	Maximum [Member]	Maximum [Member]	Maximum [Member]
			Revolving Credit Facility [Member]	Revolving Credit Facility [Member]	Accounts Receivable Sales Facility [Member]	Accounts Receivable Sales Facility [Member]
Debt Instrument [Line Items]	'	'	'	'	'	'
Unsecured Debt	$1,300,000,000	'	'	'	'	'
Debt to Capital Ratio	'	'	0.65	0.565	0.65	0.565
Credit facility	'	$1,350,000,000	'	'	'	'

Debt_And_Financing_Activities_3

Debt And Financing Activities (Schedule Of Long-Term Debt) (Details) (USD $)

Mar. 31, 2014

Mar. 31, 2013

Feb. 15, 2014

Mar. 31, 2014

Mar. 31, 2013

Mar. 31, 2014

Mar. 31, 2013

Dec. 31, 2012

Mar. 31, 2014

Mar. 31, 2013

Dec. 04, 2012

Mar. 31, 2014

Mar. 31, 2013

Mar. 31, 2014

Mar. 31, 2013

Mar. 31, 2014

Mar. 31, 2013

Mar. 05, 2014

Mar. 31, 2013

Mar. 31, 2014

Mar. 31, 2013

Mar. 08, 2013

Mar. 31, 2014

Mar. 31, 2013

Mar. 31, 2014

Mar. 05, 2014

Mar. 31, 2013

Mar. 31, 2014

Mar. 31, 2013

Dec. 31, 2012

Mar. 31, 2014

Mar. 31, 2013

Dec. 04, 2012

Mar. 31, 2013

Mar. 31, 2014

Mar. 31, 2013

Mar. 08, 2013

Mar. 31, 2014

Mar. 05, 2014

Mar. 31, 2013

Mar. 31, 2014

Mar. 31, 2013

Mar. 31, 2014

Mar. 31, 2013

Mar. 31, 2014

Mar. 05, 2014

Mar. 31, 2013

Mar. 31, 2014

Mar. 31, 2013

Mar. 31, 2014

Mar. 31, 2013

Mar. 31, 2014

Mar. 31, 2013

Mar. 31, 2014

Mar. 31, 2013

Mar. 31, 2014

Mar. 31, 2013

In Millions, unless otherwise specified

6.50% Notes Due February 15, 2014 [Member]

6.50% Notes Due February 15, 2014 [Member]

6.50% Notes Due February 15, 2014 [Member]

Floating Rate Notes Due September 10, 2015 [Member]

Floating Rate Notes Due September 10, 2015 [Member]

0.95% Notes Due December 4, 2015 [Member]

0.95% Notes Due December 4, 2015 [Member]

0.95% Notes Due December 4, 2015 [Member]

0.95% Notes Due December 4, 2015 [Member]

3.25% Notes Due March 1, 2016 [Member]

3.25% Notes Due March 1, 2016 [Member]

5.70% Notes Due March 1, 2017 [Member]

5.70% Notes Due March 1, 2017 [Member]

1.29 % Notes Due March 10, 2017 [Member]

1.29 % Notes Due March 10, 2017 [Member]

1.29 % Notes Due March 10, 2017 [Member]

1.40% Notes Due March 15, 2018 [Member]

1.40% Notes Due March 15, 2018 [Member]

1.40% Notes Due March 15, 2018 [Member]

1.40% Notes Due March 15, 2018 [Member]

7.50% Notes Due February 15, 2019 [Member]

7.50% Notes Due February 15, 2019 [Member]

2.28% Notes Due March 15, 2019 [Member]

2.28% Notes Due March 15, 2019 [Member]

2.28% Notes Due March 15, 2019 [Member]

4.75% Notes Due March 1, 2021 [Member]

4.75% Notes Due March 1, 2021 [Member]

2.70% Notes Due December 15, 2022 [Member]

2.70% Notes Due December 15, 2022 [Member]

2.70% Notes Due December 15, 2022 [Member]

2.70% Notes Due December 15, 2022 [Member]

2.85% Notes Due March 15, 2023 [Member]

2.85% Notes Due March 15, 2023 [Member]

2.85% Notes Due March 15, 2023 [Member]

2.85% Notes Due March 15, 2023 [Member]

3.80% Notes Due March 15, 2024 [Member]

3.80% Notes Due March 15, 2024 [Member]

3.80% Notes Due March 15, 2024 [Member]

7.65% Debentures Due March 1, 2027 [Member]

7.65% Debentures Due March 1, 2027 [Member]

6.00% Notes Due March 1, 2041 [Member]

6.00% Notes Due March 1, 2041 [Member]

4.88 % Notes Due March 15, 2044 [Member]

4.88 % Notes Due March 15, 2044 [Member]

4.88 % Notes Due March 15, 2044 [Member]

Other Long Term Debt [Member]

Other Long Term Debt [Member]

Celesio [Member]

Celesio [Member]

Celesio [Member]

Celesio [Member]

Celesio [Member]

Celesio [Member]

Celesio [Member]

Celesio [Member]

4.00 % Bonds Due October 18, 2016 [Member]

4.00 % Bonds Due October 18, 2016 [Member]

4.50% Bonds Due April 26, 2017 [Member]

4.50% Bonds Due April 26, 2017 [Member]

Promissory Notes [Member]

Promissory Notes [Member]

Bank Liabilities and Other [Member]

Bank Liabilities and Other [Member]

Debt Instrument [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Long-term debt

$10,373

$4,873

'

$0

$350

$400

$0

'

$499

$499

'

$599

$599

$500

$500

$700

$0

'

$499

$499

$499

'

$349

$349

$1,100

'

$0

$598

$598

'

$400

$400

'

$400

$400

$400

'

$1,100

'

$0

$175

$175

$493

$493

$800

'

$0

$27

$11

$507

$0

$737

$0

'

'

'

'

Repayments of Other Short-term Debt

'

'

350

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Interest rate on debt

'

'

6.50%

6.50%

6.50%

'

'

'

0.95%

0.95%

0.95%

3.25%

3.25%

5.70%

5.70%

1.29%

1.29%

1.29%

1.40%

1.40%

1.40%

1.40%

7.50%

7.50%

'

2.28%

'

4.75%

4.75%

'

2.70%

2.70%

2.70%

2.85%

2.85%

2.85%

2.85%

'

3.80%

'

7.65%

7.65%

6.00%

6.00%

'

4.88%

'

'

'

4.00%

4.00%

4.50%

4.50%

'

'

'

'

Debt Instrument, Maturity Date

'

'

'

15-Feb-14

15-Feb-14

'

'

4-Dec-15

4-Dec-15

4-Dec-15

'

1-Mar-16

1-Mar-16

1-Mar-17

1-Mar-17

10-Mar-17

10-Mar-17

'

15-Mar-18

15-Mar-18

15-Mar-18

'

15-Feb-19

15-Feb-19

'

'

'

1-Mar-21

1-Mar-21

15-Dec-22

15-Dec-22

15-Dec-22

'

15-Mar-23

15-Mar-23

15-Mar-23

'

'

'

'

1-Mar-27

1-Mar-27

1-Mar-41

1-Mar-41

'

'

'

'

'

18-Oct-16

18-Oct-16

26-Apr-17

26-Apr-17

'

'

'

'

Other long-term debt

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

297

0

193

0

Less current portion

-1,424

-352

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Total long-term debt

$8,949

$4,521

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Recovered_Sheet4

Debt and Financing Activities Debt and Financing Activities (Celesio Debt Acquired) (Details)

Mar. 31, 2014

Mar. 31, 2013

Nov. 30, 2013

Mar. 31, 2014

Mar. 31, 2013

Mar. 31, 2012

Mar. 31, 2014

Mar. 31, 2013

Mar. 31, 2012

Mar. 31, 2014

Feb. 06, 2014

Mar. 31, 2014

Mar. 31, 2014

Mar. 31, 2014

Mar. 31, 2014

Mar. 31, 2014

Mar. 31, 2014

Mar. 31, 2013

Mar. 31, 2014

Mar. 31, 2013

Mar. 31, 2014

Mar. 31, 2013

Mar. 31, 2014

Mar. 31, 2014

Feb. 06, 2014

Feb. 06, 2014

Mar. 31, 2014

Feb. 06, 2014

Mar. 31, 2014

Feb. 06, 2014

Mar. 31, 2014

Mar. 31, 2014

Mar. 31, 2014

Mar. 31, 2014

7-May-14

Mar. 31, 2014

7-May-14

Share data in Millions, unless otherwise specified

USD ($)

USD ($)

Accounts Receivable Sales Facility [Member]

Accounts Receivable Sales Facility [Member]

Accounts Receivable Sales Facility [Member]

Accounts Receivable Sales Facility [Member]

Revolving Credit Facility [Member]

Revolving Credit Facility [Member]

Revolving Credit Facility [Member]

Celesio [Member]

Celesio [Member]

Celesio [Member]

Celesio [Member]

Celesio [Member]

Celesio [Member]

Celesio [Member]

Celesio [Member]

Celesio [Member]

Celesio [Member]

Celesio [Member]

Celesio [Member]

Celesio [Member]

Celesio [Member]

Celesio [Member]

Celesio [Member]

Celesio [Member]

Celesio [Member]

Celesio [Member]

Celesio [Member]

Celesio [Member]

Celesio [Member]

Celesio [Member]

Revolving Credit Facility Due February Two Thousand Eighteen [Member]

Variable Interest Rate [Member]

Subsequent Event [Member]

Corporate Bond Securities [Member]

Corporate Bond Securities [Member]

USD ($)

USD ($)

USD ($)

USD ($)

USD ($)

USD ($)

USD ($)

The 2018 Bonds [Member]

Line of Credit [Member]

Long-term Debt [Member]

The 2014 Bonds [Member]

The 2014 and 2018 Bonds [Member]

Promissory Notes [Member]

Promissory Notes [Member]

4.00 % Bonds Due October 18, 2016 [Member]

4.00 % Bonds Due October 18, 2016 [Member]

4.50% Bonds Due April 26, 2017 [Member]

4.50% Bonds Due April 26, 2017 [Member]

Minimum [Member]

Maximum [Member]

Third Party Investors [Member]

Third Party Investors [Member]

Third Party Investors [Member]

Third Party Investors [Member]

Accounts Receivable Sales Facility [Member]

Accounts Receivable Sales Facility [Member]

Secured Debt [Member]

Revolving Credit Facility [Member]

Celesio [Member]

Celesio [Member]

USD ($)

Celesio [Member]

Subsequent Event [Member]

convertiblebond

USD ($)

USD ($)

convertiblebond

USD ($)

USD ($)

USD ($)

USD ($)

USD ($)

USD ($)

Promissory Notes [Member]

Promissory Notes [Member]

The 2018 Bonds [Member]

The 2014 Bonds [Member]

The 2014 and 2018 Bonds [Member]

The 2014 and 2018 Bonds [Member]

USD ($)

USD ($)

USD ($)

EUR (€)

Revolving Credit Facility [Member]

USD ($)

USD ($)

Celesio [Member]

convertiblebond

convertiblebond

USD ($)

USD ($)

Unsecured Debt [Member]

USD ($)

USD ($)

Debt Instrument [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Credit facility

'

'

'

$1,350,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

$308,000,000

'

€ 500,000,000

'

'

'

'

'

Debt Instrument, Interest Rate, Stated Percentage Rate Range, Minimum

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

1.33%

'

'

'

'

'

'

'

'

Debt Instrument, Interest Rate, Stated Percentage Rate Range, Maximum

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

2.31%

'

'

'

'

'

'

'

'

Proceeds from Lines of Credit

'

'

'

550,000,000

1,325,000,000

400,000,000

0

0

0

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

570,000,000

'

'

'

'

'

'

'

'

Repayments of Lines of Credit

'

'

'

550,000,000

1,725,000,000

0

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

575,000,000

'

'

'

'

'

'

'

'

Borrowings Outstanding

'

'

'

'

'

'

'

0

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

246,000,000

'

0

'

'

'

'

Bilateral credit line

'

'

'

'

'

'

'

'

'

'

1,662,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Short-term borrowings

346,000,000

0

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

100,000,000

'

'

'

Long-term Debt, Percentage Bearing Variable Interest, Amount

'

'

'

'

'

'

'

'

'

'

'

'

88,000,000

100,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Long-term Debt, Percentage Bearing Variable Interest, Percentage Rate

0.64%

'

'

'

'

'

'

'

'

2.35%

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Convertible bonds acquired

'

'

'

'

'

'

'

'

'

'

'

2,180

'

'

4,840

'

'

'

'

'

'

'

'

'

1,104

1,857

'

'

'

'

'

'

'

'

'

'

'

Convertible Debt

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

5,000,000

344,000,000

'

'

'

'

'

'

'

'

'

Interest rate on debt

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

4.00%

4.00%

4.50%

4.50%

1.23%

5.35%

'

'

'

'

'

'

'

'

'

'

'

'

'

Line of Credit Facility, Expiration Period

'

'

'1 year

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'4 years

'7 years

'

'

'

'

'

'

'

'

'

'

'

'

'

Other long-term debt

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

297,000,000

0

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Debt Conversion, Converted Instrument, Shares Issued

'

'

'

'

'

'

'

'

'

'

'

11.4

'

'

'

11.9

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Long-term debt

10,373,000,000

4,873,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

507,000,000

0

737,000,000

0

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Long-term Debt, Current Maturities

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

1,244,000,000

'

Long-term Debt, Fair Value

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

1,272,000,000

Corporate Bond Aggregate Par Value

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

$1,184,000,000

'

'

Variable_Interest_Entities_Nar

Variable Interest Entities (Narrative) (Details) (USD $)	Mar. 31, 2014	Mar. 31, 2013
Intangible Assets [Member]	'	'
Variable Interest Entity [Line Items]	'	'
Variable Interest Entity, Consolidated, Carrying Amount, Assets	$160,000,000	'
Variable Interest Entity, Consolidated, Carrying Amount, Liabilities	75,000,000	'
Intangible Assets [Member]	'	'
Variable Interest Entity [Line Items]	'	'
Maximum exposure to loss on assets	$1,200,000,000	$1,100,000,000

Pension_Benefits_Narrative_Det

Pension Benefits (Narrative) (Details) (USD $)

2 Months Ended

12 Months Ended

12 Months Ended

1 Months Ended

12 Months Ended

Mar. 31, 2014

Mar. 31, 2014

Mar. 31, 2014

Mar. 31, 2013

Mar. 31, 2012

Mar. 31, 2014

Mar. 31, 2014

Mar. 31, 2014

Mar. 31, 2013

Mar. 31, 2012

Mar. 31, 2014

Mar. 31, 2014

Dec. 31, 1996

Mar. 31, 2014

Mar. 31, 2013

Mar. 31, 2012

Mar. 31, 2014

Mar. 31, 2014

Mar. 31, 2014

Mar. 31, 2014

Mar. 31, 2013

Mar. 31, 2012

Mar. 31, 2014

Mar. 31, 2014

Mar. 31, 2013

Mar. 31, 2014

Mar. 31, 2013

United States Defined Contribution Pension [Member]

United States Defined Contribution Pension [Member]

United States Defined Contribution Pension [Member]

First Part Of Pay Contribution [Member]

Second Part Of Pay Contribution [Member]

Other Postretirement Benefit Plan, Defined Benefit [Member]

Other Postretirement Benefit Plan, Defined Benefit [Member]

Other Postretirement Benefit Plan, Defined Benefit [Member]

Pension Plans, Defined Benefit [Member]

Norwegian Public Service Pension Fund (SPK) [Member]

United States [Member]

United States [Member]

United States [Member]

United States [Member]

United States [Member]

United States [Member]

United States [Member]

Foreign Pension Plan, Defined Benefit [Member]

Foreign Pension Plan, Defined Benefit [Member]

Foreign Pension Plan, Defined Benefit [Member]

Pensjonsordningen for Apoteketaten (POA) [Member]

Unfunded plan [Member]

Unfunded plan [Member]

Unfunded plan [Member]

Unfunded plan [Member]

United States Defined Contribution Pension [Member]

United States Defined Contribution Pension [Member]

Equity Securities [Member]

Fixed Income Investments [Member]

Other Investments [Member]

United States [Member]

United States [Member]

Foreign Pension Plan, Defined Benefit [Member]

Foreign Pension Plan, Defined Benefit [Member]

Defined Benefit Plan Disclosure [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Defined Benefit Plan, Employer Contributions Percent Exceed Plan Asset

5.00%

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Defined Benefit Plan, Contributions by Employer

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

$5,000,000

'

'

'

'

Multiemployer Plans, Withdrawal Obligation

0

0

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Multiemployer Plans, Funded Status

'Less than 65 percent

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Defined Benefit, Plan Highest Average Pay Months

'

'

'

'

'

'

'

'

'

'

'

'

'60 months

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Defined Benefit, Plan Years Prior To Freeze Date

'

'

'

'

'

'

'

'

'

'

'

'

'15 years

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Defined Benefit Plan, Actuarial Losses, Percentage Exceeding Greater Of Projected Benefit Obligation Or Market Value of Assets

'

'

'

'

'

'

'

'

'

'

'

'

'

10.00%

'

'

'

'

'

'

'

'

'

'

'

'

'

Expected amortization of prior service cost in 2015

'

7,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Expected amortization of actuarial loss in 2015

'

31,000,000

'

'

'

'

'

-4,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Amortization of Net actuarial loss

'

36,000,000

'

'

'

'

'

'

'

'

'

'

'

32,000,000

27,000,000

23,000,000

'

'

'

4,000,000

4,000,000

2,000,000

'

'

'

'

'

Prior service (cost) credit

'

2,000,000

'

'

'

'

'

'

'

'

'

'

'

0

-1,000,000

-1,000,000

'

'

'

2,000,000

0

-1,000,000

'

'

'

'

'

Projected benefit obligation

'

'

'

'

'

'

'

119,000,000

131,000,000

144,000,000

'

'

'

540,000,000

[1]

580,000,000

[1]

527,000,000

[1]

'

'

'

934,000,000

[1]

156,000,000

[1]

143,000,000

[1]

'

188,000,000

205,000,000

260,000,000

7,000,000

Expected Benefit Payments in 2015

84,000,000

84,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Expected Benefit Payments in 2016

190,000,000

190,000,000

'

'

'

'

'

0

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Expected Benefit Payments in 2017

74,000,000

74,000,000

'

'

'

'

'

0

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Expected Benefit Payments in 2018

86,000,000

86,000,000

'

'

'

'

'

0

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Expected Benefit Payments in 2019

105,000,000

105,000,000

'

'

'

'

'

0

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Expected Benefit Payments, 2020 through 2024

413,000,000

413,000,000

'

'

'

'

'

45,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Expected Contributions in 2015

'

67,000,000

'

'

'

'

'

'

11,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Discount Rates

'

'

'

'

'

'

'

4.08%

3.84%

4.44%

'

'

'

3.58%

3.40%

'

'

'

'

3.92%

'

'

'

'

'

'

'

Rate of Decrease in Weighted Average Discount Rate

'

'

'

'

'

'

'

'

'

'

'

'

'

0.18%

'

'

'

'

'

'

'

'

'

'

'

'

'

Target Plan Asset Allocations

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

50.00%

45.00%

5.00%

'

'

'

'

'

'

'

'

Unit Value Of Cash And Cash Equivalents

'

'

'

'

'

'

'

'

'

'

$1

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Contributions to PSIP

'

'

75.00%

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Company Match Employee Contributions

'

'

'

'

'

100.00%

50.00%

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Employee Contributions

'

'

'

'

'

3.00%

2.00%

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Defined Contribution Plan, PSIP Expense

'

'

71,000,000

61,000,000

58,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Pension And Other Postretirement Defined Benefit Plans, Plan Asset Value

'

'

'

'

'

'

'

'

'

'

'

$46,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Defined Benefit Plan, Plans Obligations In Excess Of Plan Asset Shortfall Percent

1.00%

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Defined Benefit Plan, Plans Obligations In Excess Of Plan Asset Shortfall Remedy Period

'

'2 years

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

[1]

The benefit obligation is the projected benefit obligation.

Pension_Benefits_Schedule_Of_N

Pension Benefits (Schedule Of Net Periodic Expense For Pension Plans) (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013	Mar. 31, 2012
United States [Member]	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'
Service cost-benefits earned during the year	$4	$4	$4
Interest cost on projected benefit obligation	19	21	24
Expected return on assets	-20	-20	-23
Amortization of unrecognized actuarial loss, prior service costs and net transitional obligation	-32	-28	-24
Curtailment gain	0	0	0
Net periodic expense (income)	35	33	29
Foreign Pension Plan, Defined Benefit [Member]	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'
Service cost-benefits earned during the year	6	3	3
Interest cost on projected benefit obligation	11	7	7
Expected return on assets	-12	-8	-8
Amortization of unrecognized actuarial loss, prior service costs and net transitional obligation	-4	-4	-3
Curtailment gain	-1	0	0
Net periodic expense (income)	$8	$6	$5

Pension_Benefits_Schedule_Of_C

Pension Benefits (Schedule Of Changes In Benefit Obligations And Plan Assets) (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2014		Mar. 31, 2013		Mar. 31, 2012
United States [Member]	'		'		'
Defined Benefit Plan Disclosure [Line Items]	'		'		'
Benefit obligation at beginning of period	$580	[1]	$527	[1]	'
Service cost	4		4		4
Interest cost	19		21		24
Actuarial (gain) loss	-24		58		'
Benefit payments	-30		-29		'
Amendments	-9		0		'
Acquisitions	0		0		'
Foreign exchange impact and other	0		-1		'
Benefit obligation at end of period (1)	540	[1]	580	[1]	527	[1]
Fair value of plan assets at beginning of period	290		284		'
Actual return on plan assets	28		-19		'
Employer and participant contributions	12		17		'
Defined Benefit Plan, Benefits Paid, Net of Contribution	30		29		'
Acquisitions	0		0		'
Foreign exchange impact and other	0		-1		'
Fair value of plan assets at end of period	300		290		284
Funded status at end of period	-240		-290		'
Current liabilities	-13		-3		'
Long-term liabilities	-227		-287		'
Total	-240		-290		'
Foreign Pension Plan, Defined Benefit [Member]	'		'		'
Defined Benefit Plan Disclosure [Line Items]	'		'		'
Benefit obligation at beginning of period	156	[1]	143	[1]	'
Service cost	6		3		3
Interest cost	11		7		7
Actuarial (gain) loss	15		15		'
Benefit payments	-12		-6		'
Amendments	0		0		'
Acquisitions	740		0		'
Foreign exchange impact and other	18		-6		'
Benefit obligation at end of period (1)	934	[1]	156	[1]	143	[1]
Fair value of plan assets at beginning of period	135		126		'
Actual return on plan assets	-11		-12		'
Employer and participant contributions	12		8		'
Defined Benefit Plan, Benefits Paid, Net of Contribution	10		6		'
Acquisitions	426		0		'
Foreign exchange impact and other	16		-5		'
Fair value of plan assets at end of period	590		135		126
Funded status at end of period	-344		-21		'
Current liabilities	-9		0		'
Long-term liabilities	-335		-21		'
Total	($344)		($21)		'
[1]	The benefit obligation is the projected benefit obligation.

Pension_Benefits_Schedule_Of_P

Pension Benefits (Schedule Of Projected Benefit Obligation, Accumulated Benefit Obligation And Fair Value Of Plan Assets For Pension Plans) (Details) (USD $)	Mar. 31, 2014		Mar. 31, 2013		Mar. 31, 2012
In Millions, unless otherwise specified
United States [Member]	'		'		'
Defined Benefit Plan Disclosure [Line Items]	'		'		'
Projected benefit obligation	$540	[1]	$580	[1]	$527	[1]
Accumulated benefit obligation	540		579		'
Pension Plan Assets	300		290		284
Foreign Pension Plan, Defined Benefit [Member]	'		'		'
Defined Benefit Plan Disclosure [Line Items]	'		'		'
Projected benefit obligation	934	[1]	156	[1]	143	[1]
Accumulated benefit obligation	894		154		'
Pension Plan Assets	$590		$135		$126
[1]	The benefit obligation is the projected benefit obligation.

Pension_Benefits_Schedule_Of_A

Pension Benefits (Schedule Of Amounts Recognized In Accumulated Other Comprehensive Income) (Details) (USD $)	Mar. 31, 2014	Mar. 31, 2013
In Millions, unless otherwise specified
Foreign Pension Plan, Defined Benefit [Member]	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'
Net actuarial loss	$71	$59
Prior service cost	0	-2
Total	71	57
United States [Member]	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'
Net actuarial loss	188	251
Prior service cost	-7	2
Total	$181	$253

Pension_Benefits_Schedule_Of_O

Pension Benefits (Schedule Of Other Changes In Accumulated Other Comprehensive Income) (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2014		Mar. 31, 2013		Mar. 31, 2012
Defined Benefit Plan Disclosure [Line Items]	'		'		'
Net actuarial loss	($36)		'		'
Prior service (cost) credit	2		'		'
United States [Member]	'		'		'
Defined Benefit Plan Disclosure [Line Items]	'		'		'
Net actuarial loss	-31		59		42
Prior service credit	-8		0		0
Net actuarial loss	-32		-27		-23
Prior service (cost) credit	0		-1		-1
Foreign exchange impact and other	-1		0		0
Total recognized in net periodic benefit cost and other comprehensive loss (income)	-72		31		18
Projected benefit obligation	540	[1]	580	[1]	527	[1]
Foreign Pension Plan, Defined Benefit [Member]	'		'		'
Defined Benefit Plan Disclosure [Line Items]	'		'		'
Net actuarial loss	12		11		19
Prior service credit	0		0		0
Net actuarial loss	-4		-4		-2
Prior service (cost) credit	2		0		-1
Foreign exchange impact and other	4		-4		0
Total recognized in net periodic benefit cost and other comprehensive loss (income)	14		3		16
Projected benefit obligation	$934	[1]	$156	[1]	$143	[1]
[1]	The benefit obligation is the projected benefit obligation.

Pension_Benefits_Schedule_Of_W

Pension Benefits (Schedule Of Weighted-Average Assumptions Used to Estimate Net Periodic Pension Expense and Actuarial Present Value of Benefit Obligations) (Details)	12 Months Ended
	Mar. 31, 2014	Mar. 31, 2013	Mar. 31, 2012
United States [Member]	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'
Net periodic pension expense, Discount rates	3.39%	4.11%	4.82%
Net periodic pension expense, Rate of increase in compensation	4.00%	4.00%	4.00%
Net periodic pension expense, Expected long-term rate of return on plan assets	7.25%	7.25%	8.00%
Defined Benefit Plan Assumptions Used Calculating Benefit Obligation Discount Rates	3.58%	3.40%	4.15%
Benefit Obligations Assumptions Rate Increase in Compensation	4.00%	4.00%	4.00%
Benefit obligation, Discount Rate	3.58%	3.40%	'
Foreign Pension Plan, Defined Benefit [Member]	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'
Net periodic pension expense, Discount rates	3.95%	4.50%	5.42%
Net periodic pension expense, Rate of increase in compensation	2.66%	3.10%	3.45%
Net periodic pension expense, Expected long-term rate of return on plan assets	5.71%	6.13%	6.42%
Defined Benefit Plan Assumptions Used Calculating Benefit Obligation Discount Rates	3.92%	4.10%	4.51%
Benefit Obligations Assumptions Rate Increase in Compensation	3.27%	3.05%	3.06%
Benefit obligation, Discount Rate	3.92%	'	'

Pension_Benefits_Schedule_Of_S

Pension Benefits (Schedule Of Sensitivity To Changes In Weighted-Average Discount Rate For Pension Plans) (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2014
United States [Member]	'
Defined Benefit Plan Disclosure [Line Items]	'
One percentage point increase on projected benefit obligation	($35)
One percentage point decrease on projected benefit obligation	40
One percentage point increase on net periodic pension cost	-2
One percentage point decrease on net periodic pension cost	2
Foreign Pension Plan, Defined Benefit [Member]	'
Defined Benefit Plan Disclosure [Line Items]	'
One percentage point increase on projected benefit obligation	-97
One percentage point decrease on projected benefit obligation	119
One percentage point increase on net periodic pension cost	-3
One percentage point decrease on net periodic pension cost	$4

Pension_Benefits_Summary_Of_Pe

Pension Benefits (Summary Of Pension Plan Assets Using Fair Value Hierarchy By Asset Class) (Details) (USD $)	Mar. 31, 2014		Mar. 31, 2013		Mar. 31, 2012
In Millions, unless otherwise specified
United States [Member]	'		'		'
Defined Benefit Plan Disclosure [Line Items]	'		'		'
Pension Plan Assets	$300		$290		$284
United States [Member] | Cash and Cash Equivalents [Member]	'		'		'
Defined Benefit Plan Disclosure [Line Items]	'		'		'
Pension Plan Assets	8		8		'
United States [Member] | Equity Securities [Member]	'		'		'
Defined Benefit Plan Disclosure [Line Items]	'		'		'
Pension Plan Assets	19		20		'
United States [Member] | Equity Funds [Member]	'		'		'
Defined Benefit Plan Disclosure [Line Items]	'		'		'
Pension Plan Assets	132		127		'
United States [Member] | Government Securities [Member]	'		'		'
Defined Benefit Plan Disclosure [Line Items]	'		'		'
Pension Plan Assets	7		12		'
United States [Member] | Corporate Bonds [Member]	'		'		'
Defined Benefit Plan Disclosure [Line Items]	'		'		'
Pension Plan Assets	22		19		'
United States [Member] | Mortgage Backed Securities [Member]	'		'		'
Defined Benefit Plan Disclosure [Line Items]	'		'		'
Pension Plan Assets	10		6		'
United States [Member] | Asset-backed Securities and Other [Member]	'		'		'
Defined Benefit Plan Disclosure [Line Items]	'		'		'
Pension Plan Assets	22		22		'
United States [Member] | Fixed Income Funds [Member]	'		'		'
Defined Benefit Plan Disclosure [Line Items]	'		'		'
Pension Plan Assets	63		61		'
United States [Member] | Real Estate Funds [Member]	'		'		'
Defined Benefit Plan Disclosure [Line Items]	'		'		'
Pension Plan Assets	16		14		'
United States [Member] | Other Commingled Funds [Member]	'		'		'
Defined Benefit Plan Disclosure [Line Items]	'		'		'
Pension Plan Assets	0		'		'
United States [Member] | Other funds [Member]	'		'		'
Defined Benefit Plan Disclosure [Line Items]	'		'		'
Pension Plan Assets	0		'		'
United States [Member] | Total [Member]	'		'		'
Defined Benefit Plan Disclosure [Line Items]	'		'		'
Pension Plan Assets	299		289		'
United States [Member] | Receivables [Member]	'		'		'
Defined Benefit Plan Disclosure [Line Items]	'		'		'
Pension Plan Assets	1	[1]	1	[2]	'
United States [Member] | Fair Value, Inputs, Level 1 [Member] | Cash and Cash Equivalents [Member]	'		'		'
Defined Benefit Plan Disclosure [Line Items]	'		'		'
Pension Plan Assets	8		0		'
United States [Member] | Fair Value, Inputs, Level 1 [Member] | Equity Securities [Member]	'		'		'
Defined Benefit Plan Disclosure [Line Items]	'		'		'
Pension Plan Assets	19		20		'
United States [Member] | Fair Value, Inputs, Level 1 [Member] | Equity Funds [Member]	'		'		'
Defined Benefit Plan Disclosure [Line Items]	'		'		'
Pension Plan Assets	0		0		'
United States [Member] | Fair Value, Inputs, Level 1 [Member] | Government Securities [Member]	'		'		'
Defined Benefit Plan Disclosure [Line Items]	'		'		'
Pension Plan Assets	0		0		'
United States [Member] | Fair Value, Inputs, Level 1 [Member] | Corporate Bonds [Member]	'		'		'
Defined Benefit Plan Disclosure [Line Items]	'		'		'
Pension Plan Assets	0		0		'
United States [Member] | Fair Value, Inputs, Level 1 [Member] | Mortgage Backed Securities [Member]	'		'		'
Defined Benefit Plan Disclosure [Line Items]	'		'		'
Pension Plan Assets	0		0		'
United States [Member] | Fair Value, Inputs, Level 1 [Member] | Asset-backed Securities and Other [Member]	'		'		'
Defined Benefit Plan Disclosure [Line Items]	'		'		'
Pension Plan Assets	0		0		'
United States [Member] | Fair Value, Inputs, Level 1 [Member] | Fixed Income Funds [Member]	'		'		'
Defined Benefit Plan Disclosure [Line Items]	'		'		'
Pension Plan Assets	0		0		'
United States [Member] | Fair Value, Inputs, Level 1 [Member] | Real Estate Funds [Member]	'		'		'
Defined Benefit Plan Disclosure [Line Items]	'		'		'
Pension Plan Assets	0		0		'
United States [Member] | Fair Value, Inputs, Level 1 [Member] | Other Commingled Funds [Member]	'		'		'
Defined Benefit Plan Disclosure [Line Items]	'		'		'
Pension Plan Assets	0		'		'
United States [Member] | Fair Value, Inputs, Level 1 [Member] | Other funds [Member]	'		'		'
Defined Benefit Plan Disclosure [Line Items]	'		'		'
Pension Plan Assets	0		'		'
United States [Member] | Fair Value, Inputs, Level 1 [Member] | Total [Member]	'		'		'
Defined Benefit Plan Disclosure [Line Items]	'		'		'
Pension Plan Assets	27		20		'
United States [Member] | Fair Value, Inputs, Level 2 [Member] | Cash and Cash Equivalents [Member]	'		'		'
Defined Benefit Plan Disclosure [Line Items]	'		'		'
Pension Plan Assets	0		8		'
United States [Member] | Fair Value, Inputs, Level 2 [Member] | Equity Securities [Member]	'		'		'
Defined Benefit Plan Disclosure [Line Items]	'		'		'
Pension Plan Assets	0		0		'
United States [Member] | Fair Value, Inputs, Level 2 [Member] | Equity Funds [Member]	'		'		'
Defined Benefit Plan Disclosure [Line Items]	'		'		'
Pension Plan Assets	132		127		'
United States [Member] | Fair Value, Inputs, Level 2 [Member] | Government Securities [Member]	'		'		'
Defined Benefit Plan Disclosure [Line Items]	'		'		'
Pension Plan Assets	7		12		'
United States [Member] | Fair Value, Inputs, Level 2 [Member] | Corporate Bonds [Member]	'		'		'
Defined Benefit Plan Disclosure [Line Items]	'		'		'
Pension Plan Assets	22		19		'
United States [Member] | Fair Value, Inputs, Level 2 [Member] | Mortgage Backed Securities [Member]	'		'		'
Defined Benefit Plan Disclosure [Line Items]	'		'		'
Pension Plan Assets	10		6		'
United States [Member] | Fair Value, Inputs, Level 2 [Member] | Asset-backed Securities and Other [Member]	'		'		'
Defined Benefit Plan Disclosure [Line Items]	'		'		'
Pension Plan Assets	22		22		'
United States [Member] | Fair Value, Inputs, Level 2 [Member] | Fixed Income Funds [Member]	'		'		'
Defined Benefit Plan Disclosure [Line Items]	'		'		'
Pension Plan Assets	63		61		'
United States [Member] | Fair Value, Inputs, Level 2 [Member] | Real Estate Funds [Member]	'		'		'
Defined Benefit Plan Disclosure [Line Items]	'		'		'
Pension Plan Assets	0		0		'
United States [Member] | Fair Value, Inputs, Level 2 [Member] | Other Commingled Funds [Member]	'		'		'
Defined Benefit Plan Disclosure [Line Items]	'		'		'
Pension Plan Assets	0		'		'
United States [Member] | Fair Value, Inputs, Level 2 [Member] | Other funds [Member]	'		'		'
Defined Benefit Plan Disclosure [Line Items]	'		'		'
Pension Plan Assets	0		'		'
United States [Member] | Fair Value, Inputs, Level 2 [Member] | Total [Member]	'		'		'
Defined Benefit Plan Disclosure [Line Items]	'		'		'
Pension Plan Assets	256		255		'
United States [Member] | Fair Value, Inputs, Level 3 [Member]	'		'		'
Defined Benefit Plan Disclosure [Line Items]	'		'		'
Pension Plan Assets	16		14		12
United States [Member] | Fair Value, Inputs, Level 3 [Member] | Cash and Cash Equivalents [Member]	'		'		'
Defined Benefit Plan Disclosure [Line Items]	'		'		'
Pension Plan Assets	0		0		'
United States [Member] | Fair Value, Inputs, Level 3 [Member] | Equity Securities [Member]	'		'		'
Defined Benefit Plan Disclosure [Line Items]	'		'		'
Pension Plan Assets	0		0		'
United States [Member] | Fair Value, Inputs, Level 3 [Member] | Equity Funds [Member]	'		'		'
Defined Benefit Plan Disclosure [Line Items]	'		'		'
Pension Plan Assets	0		0		'
United States [Member] | Fair Value, Inputs, Level 3 [Member] | Government Securities [Member]	'		'		'
Defined Benefit Plan Disclosure [Line Items]	'		'		'
Pension Plan Assets	0		0		'
United States [Member] | Fair Value, Inputs, Level 3 [Member] | Corporate Bonds [Member]	'		'		'
Defined Benefit Plan Disclosure [Line Items]	'		'		'
Pension Plan Assets	0		0		'
United States [Member] | Fair Value, Inputs, Level 3 [Member] | Mortgage Backed Securities [Member]	'		'		'
Defined Benefit Plan Disclosure [Line Items]	'		'		'
Pension Plan Assets	0		0		'
United States [Member] | Fair Value, Inputs, Level 3 [Member] | Asset-backed Securities and Other [Member]	'		'		'
Defined Benefit Plan Disclosure [Line Items]	'		'		'
Pension Plan Assets	0		0		'
United States [Member] | Fair Value, Inputs, Level 3 [Member] | Fixed Income Funds [Member]	'		'		'
Defined Benefit Plan Disclosure [Line Items]	'		'		'
Pension Plan Assets	0		0		'
United States [Member] | Fair Value, Inputs, Level 3 [Member] | Real Estate Funds [Member]	'		'		'
Defined Benefit Plan Disclosure [Line Items]	'		'		'
Pension Plan Assets	16		14		12
United States [Member] | Fair Value, Inputs, Level 3 [Member] | Other Commingled Funds [Member]	'		'		'
Defined Benefit Plan Disclosure [Line Items]	'		'		'
Pension Plan Assets	0		'		'
United States [Member] | Fair Value, Inputs, Level 3 [Member] | Other funds [Member]	'		'		'
Defined Benefit Plan Disclosure [Line Items]	'		'		'
Pension Plan Assets	0		'		'
United States [Member] | Fair Value, Inputs, Level 3 [Member] | Total [Member]	'		'		'
Defined Benefit Plan Disclosure [Line Items]	'		'		'
Pension Plan Assets	16		14		'
Foreign Pension Plan, Defined Benefit [Member]	'		'		'
Defined Benefit Plan Disclosure [Line Items]	'		'		'
Pension Plan Assets	590		135		126
Foreign Pension Plan, Defined Benefit [Member] | Cash and Cash Equivalents [Member]	'		'		'
Defined Benefit Plan Disclosure [Line Items]	'		'		'
Pension Plan Assets	7		3		'
Foreign Pension Plan, Defined Benefit [Member] | Equity Securities [Member]	'		'		'
Defined Benefit Plan Disclosure [Line Items]	'		'		'
Pension Plan Assets	0		0		'
Foreign Pension Plan, Defined Benefit [Member] | Equity Funds [Member]	'		'		'
Defined Benefit Plan Disclosure [Line Items]	'		'		'
Pension Plan Assets	163		82		'
Foreign Pension Plan, Defined Benefit [Member] | Government Securities [Member]	'		'		'
Defined Benefit Plan Disclosure [Line Items]	'		'		'
Pension Plan Assets	4		0		'
Foreign Pension Plan, Defined Benefit [Member] | Corporate Bonds [Member]	'		'		'
Defined Benefit Plan Disclosure [Line Items]	'		'		'
Pension Plan Assets	242		9		'
Foreign Pension Plan, Defined Benefit [Member] | Mortgage Backed Securities [Member]	'		'		'
Defined Benefit Plan Disclosure [Line Items]	'		'		'
Pension Plan Assets	0		0		'
Foreign Pension Plan, Defined Benefit [Member] | Asset-backed Securities and Other [Member]	'		'		'
Defined Benefit Plan Disclosure [Line Items]	'		'		'
Pension Plan Assets	0		0		'
Foreign Pension Plan, Defined Benefit [Member] | Fixed Income Funds [Member]	'		'		'
Defined Benefit Plan Disclosure [Line Items]	'		'		'
Pension Plan Assets	45		36		'
Foreign Pension Plan, Defined Benefit [Member] | Real Estate Funds [Member]	'		'		'
Defined Benefit Plan Disclosure [Line Items]	'		'		'
Pension Plan Assets	26		5		'
Foreign Pension Plan, Defined Benefit [Member] | Other Commingled Funds [Member]	'		'		'
Defined Benefit Plan Disclosure [Line Items]	'		'		'
Pension Plan Assets	52		'		'
Foreign Pension Plan, Defined Benefit [Member] | Other funds [Member]	'		'		'
Defined Benefit Plan Disclosure [Line Items]	'		'		'
Pension Plan Assets	51		'		'
Foreign Pension Plan, Defined Benefit [Member] | Total [Member]	'		'		'
Defined Benefit Plan Disclosure [Line Items]	'		'		'
Pension Plan Assets	590		135		'
Foreign Pension Plan, Defined Benefit [Member] | Receivables [Member]	'		'		'
Defined Benefit Plan Disclosure [Line Items]	'		'		'
Pension Plan Assets	0	[1]	0	[2]	'
Foreign Pension Plan, Defined Benefit [Member] | Fair Value, Inputs, Level 1 [Member] | Cash and Cash Equivalents [Member]	'		'		'
Defined Benefit Plan Disclosure [Line Items]	'		'		'
Pension Plan Assets	7		3		'
Foreign Pension Plan, Defined Benefit [Member] | Fair Value, Inputs, Level 1 [Member] | Equity Securities [Member]	'		'		'
Defined Benefit Plan Disclosure [Line Items]	'		'		'
Pension Plan Assets	0		0		'
Foreign Pension Plan, Defined Benefit [Member] | Fair Value, Inputs, Level 1 [Member] | Equity Funds [Member]	'		'		'
Defined Benefit Plan Disclosure [Line Items]	'		'		'
Pension Plan Assets	6		0		'
Foreign Pension Plan, Defined Benefit [Member] | Fair Value, Inputs, Level 1 [Member] | Government Securities [Member]	'		'		'
Defined Benefit Plan Disclosure [Line Items]	'		'		'
Pension Plan Assets	4		0		'
Foreign Pension Plan, Defined Benefit [Member] | Fair Value, Inputs, Level 1 [Member] | Corporate Bonds [Member]	'		'		'
Defined Benefit Plan Disclosure [Line Items]	'		'		'
Pension Plan Assets	6		0		'
Foreign Pension Plan, Defined Benefit [Member] | Fair Value, Inputs, Level 1 [Member] | Mortgage Backed Securities [Member]	'		'		'
Defined Benefit Plan Disclosure [Line Items]	'		'		'
Pension Plan Assets	0		0		'
Foreign Pension Plan, Defined Benefit [Member] | Fair Value, Inputs, Level 1 [Member] | Asset-backed Securities and Other [Member]	'		'		'
Defined Benefit Plan Disclosure [Line Items]	'		'		'
Pension Plan Assets	0		0		'
Foreign Pension Plan, Defined Benefit [Member] | Fair Value, Inputs, Level 1 [Member] | Fixed Income Funds [Member]	'		'		'
Defined Benefit Plan Disclosure [Line Items]	'		'		'
Pension Plan Assets	0		0		'
Foreign Pension Plan, Defined Benefit [Member] | Fair Value, Inputs, Level 1 [Member] | Real Estate Funds [Member]	'		'		'
Defined Benefit Plan Disclosure [Line Items]	'		'		'
Pension Plan Assets	0		0		'
Foreign Pension Plan, Defined Benefit [Member] | Fair Value, Inputs, Level 1 [Member] | Other Commingled Funds [Member]	'		'		'
Defined Benefit Plan Disclosure [Line Items]	'		'		'
Pension Plan Assets	3		'		'
Foreign Pension Plan, Defined Benefit [Member] | Fair Value, Inputs, Level 1 [Member] | Other funds [Member]	'		'		'
Defined Benefit Plan Disclosure [Line Items]	'		'		'
Pension Plan Assets	0		'		'
Foreign Pension Plan, Defined Benefit [Member] | Fair Value, Inputs, Level 1 [Member] | Total [Member]	'		'		'
Defined Benefit Plan Disclosure [Line Items]	'		'		'
Pension Plan Assets	26		3		'
Foreign Pension Plan, Defined Benefit [Member] | Fair Value, Inputs, Level 2 [Member] | Cash and Cash Equivalents [Member]	'		'		'
Defined Benefit Plan Disclosure [Line Items]	'		'		'
Pension Plan Assets	0		0		'
Foreign Pension Plan, Defined Benefit [Member] | Fair Value, Inputs, Level 2 [Member] | Equity Securities [Member]	'		'		'
Defined Benefit Plan Disclosure [Line Items]	'		'		'
Pension Plan Assets	0		0		'
Foreign Pension Plan, Defined Benefit [Member] | Fair Value, Inputs, Level 2 [Member] | Equity Funds [Member]	'		'		'
Defined Benefit Plan Disclosure [Line Items]	'		'		'
Pension Plan Assets	157		82		'
Foreign Pension Plan, Defined Benefit [Member] | Fair Value, Inputs, Level 2 [Member] | Government Securities [Member]	'		'		'
Defined Benefit Plan Disclosure [Line Items]	'		'		'
Pension Plan Assets	0		0		'
Foreign Pension Plan, Defined Benefit [Member] | Fair Value, Inputs, Level 2 [Member] | Corporate Bonds [Member]	'		'		'
Defined Benefit Plan Disclosure [Line Items]	'		'		'
Pension Plan Assets	236		9		'
Foreign Pension Plan, Defined Benefit [Member] | Fair Value, Inputs, Level 2 [Member] | Mortgage Backed Securities [Member]	'		'		'
Defined Benefit Plan Disclosure [Line Items]	'		'		'
Pension Plan Assets	0		0		'
Foreign Pension Plan, Defined Benefit [Member] | Fair Value, Inputs, Level 2 [Member] | Asset-backed Securities and Other [Member]	'		'		'
Defined Benefit Plan Disclosure [Line Items]	'		'		'
Pension Plan Assets	0		0		'
Foreign Pension Plan, Defined Benefit [Member] | Fair Value, Inputs, Level 2 [Member] | Fixed Income Funds [Member]	'		'		'
Defined Benefit Plan Disclosure [Line Items]	'		'		'
Pension Plan Assets	45		36		'
Foreign Pension Plan, Defined Benefit [Member] | Fair Value, Inputs, Level 2 [Member] | Real Estate Funds [Member]	'		'		'
Defined Benefit Plan Disclosure [Line Items]	'		'		'
Pension Plan Assets	19		0		'
Foreign Pension Plan, Defined Benefit [Member] | Fair Value, Inputs, Level 2 [Member] | Other Commingled Funds [Member]	'		'		'
Defined Benefit Plan Disclosure [Line Items]	'		'		'
Pension Plan Assets	49		'		'
Foreign Pension Plan, Defined Benefit [Member] | Fair Value, Inputs, Level 2 [Member] | Other funds [Member]	'		'		'
Defined Benefit Plan Disclosure [Line Items]	'		'		'
Pension Plan Assets	46		'		'
Foreign Pension Plan, Defined Benefit [Member] | Fair Value, Inputs, Level 2 [Member] | Total [Member]	'		'		'
Defined Benefit Plan Disclosure [Line Items]	'		'		'
Pension Plan Assets	552		127		'
Foreign Pension Plan, Defined Benefit [Member] | Fair Value, Inputs, Level 3 [Member]	'		'		'
Defined Benefit Plan Disclosure [Line Items]	'		'		'
Pension Plan Assets	12		5		5
Foreign Pension Plan, Defined Benefit [Member] | Fair Value, Inputs, Level 3 [Member] | Cash and Cash Equivalents [Member]	'		'		'
Defined Benefit Plan Disclosure [Line Items]	'		'		'
Pension Plan Assets	0		0		'
Foreign Pension Plan, Defined Benefit [Member] | Fair Value, Inputs, Level 3 [Member] | Equity Securities [Member]	'		'		'
Defined Benefit Plan Disclosure [Line Items]	'		'		'
Pension Plan Assets	0		0		'
Foreign Pension Plan, Defined Benefit [Member] | Fair Value, Inputs, Level 3 [Member] | Equity Funds [Member]	'		'		'
Defined Benefit Plan Disclosure [Line Items]	'		'		'
Pension Plan Assets	0		0		'
Foreign Pension Plan, Defined Benefit [Member] | Fair Value, Inputs, Level 3 [Member] | Government Securities [Member]	'		'		'
Defined Benefit Plan Disclosure [Line Items]	'		'		'
Pension Plan Assets	0		0		'
Foreign Pension Plan, Defined Benefit [Member] | Fair Value, Inputs, Level 3 [Member] | Corporate Bonds [Member]	'		'		'
Defined Benefit Plan Disclosure [Line Items]	'		'		'
Pension Plan Assets	0		0		'
Foreign Pension Plan, Defined Benefit [Member] | Fair Value, Inputs, Level 3 [Member] | Mortgage Backed Securities [Member]	'		'		'
Defined Benefit Plan Disclosure [Line Items]	'		'		'
Pension Plan Assets	0		0		'
Foreign Pension Plan, Defined Benefit [Member] | Fair Value, Inputs, Level 3 [Member] | Asset-backed Securities and Other [Member]	'		'		'
Defined Benefit Plan Disclosure [Line Items]	'		'		'
Pension Plan Assets	0		0		'
Foreign Pension Plan, Defined Benefit [Member] | Fair Value, Inputs, Level 3 [Member] | Fixed Income Funds [Member]	'		'		'
Defined Benefit Plan Disclosure [Line Items]	'		'		'
Pension Plan Assets	0		0		'
Foreign Pension Plan, Defined Benefit [Member] | Fair Value, Inputs, Level 3 [Member] | Real Estate Funds [Member]	'		'		'
Defined Benefit Plan Disclosure [Line Items]	'		'		'
Pension Plan Assets	7		5		5
Foreign Pension Plan, Defined Benefit [Member] | Fair Value, Inputs, Level 3 [Member] | Other Commingled Funds [Member]	'		'		'
Defined Benefit Plan Disclosure [Line Items]	'		'		'
Pension Plan Assets	0		'		'
Foreign Pension Plan, Defined Benefit [Member] | Fair Value, Inputs, Level 3 [Member] | Other funds [Member]	'		'		'
Defined Benefit Plan Disclosure [Line Items]	'		'		'
Pension Plan Assets	5		'		'
Foreign Pension Plan, Defined Benefit [Member] | Fair Value, Inputs, Level 3 [Member] | Total [Member]	'		'		'
Defined Benefit Plan Disclosure [Line Items]	'		'		'
Pension Plan Assets	$12		$5		'
[1]	Represents pending trades at MarchB 31, 2014.
[2]	Represents pending trades at MarchB 31, 2013.

Pension_Benefits_Schedule_Of_R

Pension Benefits (Schedule Of Reconciliation Of Level 3 Plan Assets Held) (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013
United States [Member]	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'
Acquisitions	$0	$0
Fair value of plan assets at beginning of period	290	284
Fair value of plan assets at end of period	300	290
United States [Member] | Fair Value, Inputs, Level 3 [Member]	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'
Acquisitions	0	'
Fair value of plan assets at beginning of period	14	12
Unrealized gain on plan assets still held	2	1
Purchases, sales and settlements	0	1
Fair value of plan assets at end of period	16	14
United States [Member] | Real Estate Funds [Member]	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'
Fair value of plan assets at end of period	16	14
United States [Member] | Real Estate Funds [Member] | Fair Value, Inputs, Level 3 [Member]	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'
Acquisitions	0	'
Fair value of plan assets at beginning of period	14	12
Unrealized gain on plan assets still held	2	1
Purchases, sales and settlements	0	1
Fair value of plan assets at end of period	16	14
United States [Member] | Hedge Funds [Member] | Fair Value, Inputs, Level 3 [Member]	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'
Acquisitions	0	'
Fair value of plan assets at beginning of period	0	0
Unrealized gain on plan assets still held	0	0
Purchases, sales and settlements	0	0
Fair value of plan assets at end of period	0	0
Foreign Pension Plan, Defined Benefit [Member]	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'
Acquisitions	-426	0
Fair value of plan assets at beginning of period	135	126
Fair value of plan assets at end of period	590	135
Foreign Pension Plan, Defined Benefit [Member] | Fair Value, Inputs, Level 3 [Member]	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'
Acquisitions	6	'
Fair value of plan assets at beginning of period	5	5
Unrealized gain on plan assets still held	1	0
Purchases, sales and settlements	0	0
Fair value of plan assets at end of period	12	5
Foreign Pension Plan, Defined Benefit [Member] | Real Estate Funds [Member]	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'
Fair value of plan assets at end of period	26	5
Foreign Pension Plan, Defined Benefit [Member] | Real Estate Funds [Member] | Fair Value, Inputs, Level 3 [Member]	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'
Acquisitions	1	'
Fair value of plan assets at beginning of period	5	5
Unrealized gain on plan assets still held	1	0
Purchases, sales and settlements	0	0
Fair value of plan assets at end of period	7	5
Foreign Pension Plan, Defined Benefit [Member] | Hedge Funds [Member] | Fair Value, Inputs, Level 3 [Member]	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'
Acquisitions	5	'
Fair value of plan assets at beginning of period	0	0
Unrealized gain on plan assets still held	0	0
Purchases, sales and settlements	0	0
Fair value of plan assets at end of period	$5	$0

Postretirement_Benefits_Narrat

Postretirement Benefits (Narrative) (Details) (USD $)	1 Months Ended	12 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2013	Mar. 31, 2014	Mar. 31, 2013	Mar. 31, 2012
Defined Benefit Plan Disclosure [Line Items]	'	'	'	'
Defined Benefit Plan, Expected Future Benefit Payments, Year Two	'	$190	'	'
Expected amortization of actuarial loss from stockholders' equity in 2015	'	-31	'	'
Other postretirement plan expected future benefit payments, 2020 through 2024	'	413	'	'
Expected contributions for postretirement benefit plans in 2015	'	67	'	'
Other Postretirement Benefit Plan, Defined Benefit [Member]	'	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'	'
Defined Benefit Plan, Expected Future Benefit Payments, Year Two	'	0	'	'
Net actuarial gains (losses) for post retirement plans	6	8	6	'
Net prior service credits for post retirement plans	1	1	1	'
Net actuarial gains (loss) for changes in benefit obligations	'	2	7	3
Expected amortization of actuarial loss from stockholders' equity in 2015	'	4	'	'
Amortization of actuarial loss from stockholders' equity	'	1	'	'
Defined Benefit Plan Expected Future Benefit Payments Five Fiscal Years Beginning 2015	'	10	'	'
Other postretirement plan expected future benefit payments, 2020 through 2024	'	45	'	'
Expected contributions for postretirement benefit plans in 2015	'	'	$11	'
Weighted-average discount rates used to estimate postretirement welfare benefit expenses	'	3.84%	4.44%	5.09%
Weighted-average discount rates for actuarial present value of benefit obligations	3.84%	4.08%	3.84%	4.44%
Actuarial Gain Loss Postretirement Welfare Benefit Plan Amortization Period	'3 years	'	'	'
Prescription Drugs [Member] | Other Postretirement Benefit Plan, Defined Benefit [Member]	'	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'	'
Assumed health care cost trend rate	'	7.00%	'	'
Pension and Other Postretirement Benefit Plans, Assumptions Used Calculating Postretirement Benefit Obligation	'	'	7.50%	'
Dental [Member] | Other Postretirement Benefit Plan, Defined Benefit [Member]	'	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'	'
Pension and Other Postretirement Benefit Plans, Assumptions Used Calculating Postretirement Benefit Obligation	'	5.00%	5.25%	'
Pre-65 [Member] | Other Postretirement Benefit Plan, Defined Benefit [Member]	'	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'	'
Pension and Other Postretirement Benefit Plans, Assumptions Used Calculating Postretirement Benefit Obligation	'	7.50%	'	'
Pre-65 [Member] | Medical [Member] | Other Postretirement Benefit Plan, Defined Benefit [Member]	'	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'	'
Pension and Other Postretirement Benefit Plans, Assumptions Used Calculating Postretirement Benefit Obligation	'	'	7.50%	'
Post-65 [Member] | Other Postretirement Benefit Plan, Defined Benefit [Member]	'	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'	'
Pension and Other Postretirement Benefit Plans, Assumptions Used Calculating Postretirement Benefit Obligation	'	7.00%	'	'
Post-65 [Member] | Medical [Member] | Other Postretirement Benefit Plan, Defined Benefit [Member]	'	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'	'
Pension and Other Postretirement Benefit Plans, Assumptions Used Calculating Postretirement Benefit Obligation	'	'	7.25%	'

Postretirement_Benefits_Schedu

Postretirement Benefits (Schedule Of Net Periodic Expense (Income) For Postretirement Welfare Benefits) (Details) (Other Postretirement Benefit Plan, Defined Benefit [Member], USD $)	12 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013	Mar. 31, 2012
Other Postretirement Benefit Plan, Defined Benefit [Member]	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'
Service cost	$2	$2	$2
Interest cost	5	6	7
Amortization of unrecognized actuarial gain and prior service costs	-1	-2	-1
Curtailment gain	-2	0	0
Net periodic expense (income)	$4	$6	$8

Postretirement_Benefits_Schedu1

Postretirement Benefits (Schedule Of Changes In Benefit Obligations For Postretirement Welfare Plans) (Details) (Other Postretirement Benefit Plan, Defined Benefit [Member], USD $)	12 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013	Mar. 31, 2012
Other Postretirement Benefit Plan, Defined Benefit [Member]	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'
Defined Benefit Plan, Curtailments	($2)	$0	'
Benefit obligation at beginning of period	131	144	'
Service cost	2	2	2
Interest cost	5	6	7
Actuarial (gain) loss	-2	-9	'
Benefit payments	-15	-12	'
Benefit obligation at end of period (1)	$119	$131	$144

Hedging_Activities_Narrative_D

Hedging Activities (Narrative) (Details) (USD $)	Mar. 31, 2014
In Millions, unless otherwise specified
Not Designated as Hedging Instrument [Member]	'
Derivative [Line Items]	'
Derivative, Notional Amount	$1,091
Forward Contracts [Member] | Designated as Hedging Instrument [Member]	'
Derivative [Line Items]	'
Derivative, Notional Amount	463
Interest Rate Swap [Member] | Not Designated as Hedging Instrument [Member]	'
Derivative [Line Items]	'
Derivative, Notional Amount	$96

Hedging_Activities_Derivative_1

Hedging Activities Derivative Instruments Fair Value (Details) (USD $)	Mar. 31, 2014	Mar. 31, 2013
In Millions, unless otherwise specified
Foreign Exchange Contract [Member] | Designated as Hedging Instrument [Member]	'	'
Derivatives, Fair Value [Line Items]	'	'
Derivative Asset, Fair Value, Gross Asset	$31	$5
Derivative Liability, Fair Value, Gross Liability	0	1
Foreign Exchange Contract [Member] | Designated as Hedging Instrument [Member] | Prepaid Expenses and Other Current Assets [Member]	'	'
Derivatives, Fair Value [Line Items]	'	'
Derivative Asset, Fair Value, Gross Asset	4	0
Derivative Liability, Fair Value, Gross Liability	0	0
Derivative Asset, Notional Amount	64	0
Foreign Exchange Contract [Member] | Designated as Hedging Instrument [Member] | Other Assets [Member]	'	'
Derivatives, Fair Value [Line Items]	'	'
Derivative Asset, Fair Value, Gross Asset	27	5
Derivative Liability, Fair Value, Gross Liability	0	0
Derivative Asset, Notional Amount	399	463
Foreign Exchange Contract [Member] | Designated as Hedging Instrument [Member] | Other Current Liabilities [Member]	'	'
Derivatives, Fair Value [Line Items]	'	'
Derivative Asset, Fair Value, Gross Asset	0	0
Derivative Liability, Fair Value, Gross Liability	0	1
Derivative Liability, Notional Amount	0	41
Foreign Exchange Contract [Member] | Not Designated as Hedging Instrument [Member]	'	'
Derivatives, Fair Value [Line Items]	'	'
Derivative Asset, Fair Value, Gross Asset	2	5
Derivative Liability, Fair Value, Gross Liability	14	0
Foreign Exchange Contract [Member] | Not Designated as Hedging Instrument [Member] | Prepaid Expenses and Other Current Assets [Member]	'	'
Derivatives, Fair Value [Line Items]	'	'
Derivative Asset, Fair Value, Gross Asset	2	5
Derivative Liability, Fair Value, Gross Liability	0	0
Derivative Asset, Notional Amount	255	177
Foreign Exchange Contract [Member] | Not Designated as Hedging Instrument [Member] | Other Current Liabilities [Member]	'	'
Derivatives, Fair Value [Line Items]	'	'
Derivative Asset, Fair Value, Gross Asset	0	0
Derivative Liability, Fair Value, Gross Liability	13	0
Derivative Liability, Notional Amount	836	0
Interest Rate Swap [Member] | Not Designated as Hedging Instrument [Member] | Other Current Liabilities [Member]	'	'
Derivatives, Fair Value [Line Items]	'	'
Derivative Asset, Fair Value, Gross Asset	0	0
Derivative Liability, Fair Value, Gross Liability	1	0
Derivative Liability, Notional Amount	$96	$0

Fair_Value_Measurements_Narrat

Fair Value Measurements (Narrative) (Details) (USD $)

12 Months Ended

3 Months Ended

12 Months Ended

3 Months Ended

12 Months Ended

3 Months Ended

12 Months Ended

3 Months Ended

Mar. 31, 2014

Mar. 31, 2013

Mar. 31, 2012

Mar. 31, 2013

Mar. 31, 2013

Mar. 31, 2013

Sep. 30, 2013

Sep. 30, 2012

Mar. 31, 2013

Mar. 31, 2014

Mar. 31, 2013

Mar. 31, 2014

Mar. 31, 2013

Mar. 31, 2013

Mar. 31, 2013

Dec. 31, 2013

Dec. 31, 2013

Distribution Solutions [Member]

Distribution Solutions [Member]

Distribution Solutions [Member]

Distribution Solutions [Member]

Distribution Solutions [Member]

Technology Solutions [Member]

Technology Solutions [Member]

Technology Solutions [Member]

Fair Value, Inputs, Level 2 [Member]

Fair Value, Inputs, Level 2 [Member]

Fair Value, Inputs, Level 3 [Member]

Fair Value, Inputs, Level 3 [Member]

International Technology [Member]

International Technology [Member]

Nadro [Member]

Nadro [Member]

Nadro [Member]

Nadro [Member]

Fair Value, Measurements, Recurring [Member]

Fair Value, Measurements, Recurring [Member]

Nadro [Member]

Technology Solutions [Member]

Fair Value, Inputs, Level 3 [Member]

Fair Value, Measurements, Nonrecurring [Member]

Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Goodwill and Intangible Asset Impairment

'

'

'

'

'

'

'

'

$46,000,000

$57,000,000

$46,000,000

'

'

'

'

$80,000,000

$80,000,000

Notes and Loans Payable, Carrying Value

10,400,000,000

4,900,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Notes and Loans Payable, Fair Value

'

'

'

'

'

'

'

'

'

'

'

10,800,000,000

5,500,000,000

'

'

'

'

Impairment of an equity investment

0

191,000,000

0

'

191,000,000

191,000,000

'

'

'

'

'

'

'

191,000,000

'

'

'

Interest in Investee

'

'

'

'

49.00%

49.00%

49.00%

49.00%

'

'

'

'

'

'

'

'

'

Goodwill, Impairment Loss

'

$36,000,000

'

$0

'

'

'

'

$36,000,000

'

$36,000,000

'

'

'

$36,000,000

'

'

Fair_Value_Measurements_Fair_V

Fair Value Measurements (Fair Value Measurements, Recurring) (Details) (Fair Value, Measurements, Recurring [Member], USD $)	Mar. 31, 2014		Mar. 31, 2013
In Millions, unless otherwise specified
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Cash Equivalents, Fair Value	$2,865		$1,578
Money Market Funds (1) [Member]	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Cash Equivalents, Fair Value	2,284	[1]	1,036	[1]
Time Deposits (2) [Member]	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Cash Equivalents, Fair Value	12	[2]	95	[2]
Repurchase Agreements (2) [Member]	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Cash Equivalents, Fair Value	569	[2]	447	[2]
Fair Value, Inputs, Level 1 [Member]	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Cash Equivalents, Fair Value	2,853		1,483
Fair Value, Inputs, Level 1 [Member] | Money Market Funds (1) [Member]	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Cash Equivalents, Fair Value	2,284	[1]	1,036	[1]
Fair Value, Inputs, Level 1 [Member] | Time Deposits (2) [Member]	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Cash Equivalents, Fair Value	0	[2]	0	[2]
Fair Value, Inputs, Level 1 [Member] | Repurchase Agreements (2) [Member]	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Cash Equivalents, Fair Value	569	[2]	447	[2]
Fair Value, Inputs, Level 2 [Member]	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Cash Equivalents, Fair Value	12		95
Fair Value, Inputs, Level 2 [Member] | Money Market Funds (1) [Member]	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Cash Equivalents, Fair Value	0	[1]	0	[1]
Fair Value, Inputs, Level 2 [Member] | Time Deposits (2) [Member]	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Cash Equivalents, Fair Value	12	[2]	95	[2]
Fair Value, Inputs, Level 2 [Member] | Repurchase Agreements (2) [Member]	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Cash Equivalents, Fair Value	0	[2]	0	[2]
Fair Value, Inputs, Level 3 [Member]	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Cash Equivalents, Fair Value	0		0
Fair Value, Inputs, Level 3 [Member] | Money Market Funds (1) [Member]	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Cash Equivalents, Fair Value	0	[1]	0	[1]
Fair Value, Inputs, Level 3 [Member] | Time Deposits (2) [Member]	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Cash Equivalents, Fair Value	0	[2]	0	[2]
Fair Value, Inputs, Level 3 [Member] | Repurchase Agreements (2) [Member]	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Cash Equivalents, Fair Value	$0	[2]	$0	[2]
[1]	Gross unrealized gain and losses were not material for the years ended March 31, 2014 and 2013. Based on quoted prices of identical investments.
[2]	The carrying amounts of these cash equivalents approximated their estimated fair values because of their short maturities.

Lease_Obligations_Narrative_De

Lease Obligations (Narrative) (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013	Mar. 31, 2012
Operating Leased Assets [Line Items]	'	'	'
Rent expense	$298	$232	$229
Renewal option increments for leases (years)	'5 years	'	'
Minimum sublease rentals, due under future noncancelable subleases	$44	'	'
Building [Member] | Minimum [Member]	'	'	'
Operating Leased Assets [Line Items]	'	'	'
Lease term (years)	'1 year	'	'
Building [Member] | Maximum [Member]	'	'	'
Operating Leased Assets [Line Items]	'	'	'
Lease term (years)	'12 years	'	'
Equipment [Member] | Minimum [Member]	'	'	'
Operating Leased Assets [Line Items]	'	'	'
Lease term (years)	'1 year	'	'
Equipment [Member] | Maximum [Member]	'	'	'
Operating Leased Assets [Line Items]	'	'	'
Lease term (years)	'5 years	'	'

Lease_Obligations_Schedule_Of_

Lease Obligations (Schedule Of Future Minimum Rental Payments For Operating Leases) (Details) (USD $)	Mar. 31, 2014
In Millions, unless otherwise specified
Leases, Operating [Abstract]	'
2015	$358
2016	299
2017	246
2018	193
2019	168
Thereafter	806
Total minimum lease payments (1)	$2,070	[1]
[1]	Minimum lease payments have not been reduced by minimum sublease rentals of $44 million due under future noncancelable subleases.

Financial_Guarantees_and_Warra1

Financial Guarantees and Warranties (Narrative) (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2014
Guarantor Obligations [Line Items]	'
Guarantor Obligations, Current Carrying Value	$4
Guarantor obligations, maximum exposure	272
Guarantee obligations, expiring in 2015	154
Guarantee obligations, expiring in 2016	31
Guarantee obligations, expiring in 2017	17
Guarantee obligations, expiring in 2018	21
Guarantee obligations, expiring in 2019	37
Guarantee obligations, expiring after 2019	216
Financial Guarantee [Member] | Minimum [Member]	'
Guarantor Obligations [Line Items]	'
Number of years for which agreements or guarantees extend	'P1Y
Financial Guarantee [Member] | Maximum [Member]	'
Guarantor Obligations [Line Items]	'
Number of years for which agreements or guarantees extend	'P2Y
Guarantee Obligations Customers Debt [Member] | Minimum [Member]	'
Guarantor Obligations [Line Items]	'
Number of years for which agreements or guarantees extend	'P1Y
Guarantee Obligations Customers Debt [Member] | Maximum [Member]	'
Guarantor Obligations [Line Items]	'
Number of years for which agreements or guarantees extend	'P15Y
Guarantee Obligations Inventory Repurchase Guarantees [Member]	'
Guarantor Obligations [Line Items]	'
Guarantor obligations, maximum exposure	204
Standby Letters of Credit [Member]	'
Guarantor Obligations [Line Items]	'
Guarantor obligations, maximum exposure	161
Commitment to investee building and equipment construction [Member]	'
Guarantor Obligations [Line Items]	'
Guarantor obligations, maximum exposure	$40

Other_Commitments_and_Continge2

Other Commitments and Contingent Liabilities (Narrative) (Details) (USD $)	0 Months Ended	12 Months Ended
In Millions, unless otherwise specified	Apr. 16, 2013	Mar. 31, 2014	Mar. 31, 2013	Mar. 31, 2012
	Defendants	site
	Relator	mckSite
	States
Loss Contingencies [Line Items]	'	'	'	'
Loss Contingency Number of States Filed On Behalf Of	21,000,000	'	'	'
Loss Contingency Number of Relators	2	'	'	'
Litigation charges	'	$68	$72	$149
Chemical conditions sites, number	'	8	'	'
Remediation costs	'	7	'	'
Amount third parties have agreed to pay in settlement	'	1	'	'
Hazardous substance sites, number	'	14	'	'
Estimated environmental assessment and cleanup costs	'	70	'	'
Estimated loss	'	$20	'	'
Loss Contingency Number of Additional Defendants	5	'	'	'
Maximum [Member]	'	'	'	'
Loss Contingencies [Line Items]	'	'	'	'
Site Contingency, Time Frame of Disbursements	'	'MarchB 2034	'	'
Minimum [Member]	'	'	'	'
Loss Contingencies [Line Items]	'	'	'	'
Site Contingency, Time Frame of Disbursements	'	'MayB 2014	'	'

Other_Commitments_and_Continge3

Other Commitments and Contingent Liabilities (Litigation Reserve and Expense) (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013	Mar. 31, 2012
Loss Contingencies [Line Items]	'	'	'
Charges incurred	$68	$72	$149
Payments Made	-105	-483	-26
Average Wholesale Price Litigation [Member]	'	'	'
Loss Contingencies [Line Items]	'	'	'
AWP Litigation Reserve, Beginning Balance	42	453	330
Charges incurred	68	72	149
Payments Made	-105	-483	-26
AWP Litigation Reserve, Ending Balance	$5	$42	$453

Stockholders_Equity_Narrative_

Stockholders' Equity (Narrative) (Details) (USD $)

12 Months Ended

12 Months Ended

1 Months Ended

In Millions, except Per Share data, unless otherwise specified

Mar. 31, 2014

Mar. 31, 2013

Mar. 31, 2012

Sep. 30, 2013

Mar. 31, 2013

Sep. 30, 2012

Mar. 31, 2013

Mar. 31, 2013

Jul. 31, 2013

Jul. 31, 2013

Nadro [Member]

Nadro [Member]

Nadro [Member]

Treasury Stock [Member]

Retained Earnings [Member]

Old Rate Per Share [Member]

New Rate Per Share [Member]

Distribution Solutions [Member]

Distribution Solutions [Member]

Distribution Solutions [Member]

Dividends Payable [Line Items]

'

'

'

'

'

'

'

'

'

'

Cash dividends declared per common share

$0.92

$0.80

$0.80

'

'

'

'

'

$0.20

$0.24

Treasury Stock, Shares, Retired

'

2

'

'

'

'

'

'

'

'

Retirement of treasury stock

'

$0

'

'

'

'

$217

($195)

'

'

Other Comprehensive (Income) Loss, Foreign Currency Transaction and Translation Adjustment, Net of Tax, Portion Attributable to Noncontrolling Interest

21

'

'

'

'

'

'

'

'

'

Interest in Investee

'

'

'

49.00%

49.00%

49.00%

'

'

'

'

Foreign Currency Translations Net losses Reclassed to Income

($44)

[1]

$0

[1]

$0

[1]

'

'

'

'

'

'

'

[1]

As a result of our sale of our 49% equity interest in Nadro, foreign currency translation net losses of $44 million were reclassified from AOCI to other income, within our consolidated statement of operations. Such losses were previously considered in our impairment evaluation of the investment when we committed to a plan to sell the investment during the fourth quarter of 2013, and accordingly did not impact earnings for 2014.

Stockholders_Equity_Shares_Rep

Stockholders' Equity (Shares Repurchased Over Last Three Years) (Details) (USD $)	12 Months Ended
In Millions, except Per Share data, unless otherwise specified	Mar. 31, 2014		Mar. 31, 2013		Mar. 31, 2012		Mar. 31, 2011
Class of Stock [Line Items]	'		'		'		'
Number of shares repurchased	0	[1],[2],[3]	13	[1],[2],[3]	20	[1],[2],[3]	'
Average price paid per share	$0	[2]	$100.82	[2]	$83.47	[2]	'
Stock Repurchase Program, Remaining Authorized Repurchase Amount, End of Period	$340	[2]	$340	[2]	$299	[2]	$499	[2]
Repurchase of common stock	0	[2]	-1,159		-1,850	[2]	'
Stock Repurchase Approved, April 2011 [Member]	'		'		'		'
Class of Stock [Line Items]	'		'		'		'
Stock Repurchase Program, Authorized Amount	'		'		1,000	[2]	'
Stock Repurchase Approved January 2012 [Member]	'		'		'		'
Class of Stock [Line Items]	'		'		'		'
Stock Repurchase Program, Authorized Amount	'		'		650	[2]	'
Stock Repurchase Approved April 2012 [Member]	'		'		'		'
Class of Stock [Line Items]	'		'		'		'
Stock Repurchase Program, Authorized Amount	'		700	[2]	'		'
Stock Repurchase Approved January 2013 [Member]	'		'		'		'
Class of Stock [Line Items]	'		'		'		'
Stock Repurchase Program, Authorized Amount	'		$500	[2]	'		'
[1]	The number of shares purchased reflects rounding adjustments.
[2]	This table does not include shares tendered to satisfy the exercise price in connection with cashless exercises of employee stock options or shares tendered to satisfy tax withholding obligations in connection with employee equity awards.
[3]	All of the shares purchased were part of the publicly announced programs.

Stockholders_Equity_Other_Comp

Stockholders' Equity (Other Comprehensive Income (Loss), Net of Tax) (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2014		Mar. 31, 2013		Mar. 31, 2012
Stockholders' Equity Note [Abstract]	'		'		'
Unrealized losses on cash flow hedges, net of income tax benefit of nil, nil and nil	($6)		$0		($5)
Foreign currency translation adjustments arising during period, net of income tax expense (benefit) of nil, ($2) and $2 (1)	9	[1]	-52	[1]	-56	[1]
Reclassified to income statement, net of income tax expense of $24, nil and nil (2)	44	[2]	0	[2]	0	[2]
Foreign currency translation adjustments, net of income tax expense (benefit) of $24, ($2) and $2	53		-52		-56
Net actuarial gain (loss) and prior service credit (cost) arising during period, net of income tax (benefit) of $16, ($22) and ($18)	17		-40		-38
Amortization of actuarial loss, prior service cost and transition obligation, net of income tax expense of $12, $12 and $9 (3)	22	[3]	18	[3]	17	[3]
Foreign currency translation adjustments, net of income tax expense of nil, nil and nil	-4		4		0
Reclassified to income statement, net of income tax expense of $1, nil and nil	1		0		0
Retirement related benefit plans, net of income tax expense (benefit) of ($10), ($10) and ($9)	36		-18		-21
Other Comprehensive Income (Loss), Net of Tax	$83		($70)		($82)
[1]	The 2014 amounts include net foreign currency translation gain of $21 million attributable to noncontrolling interests.
[2]	As a result of our sale of our 49% equity interest in Nadro, foreign currency translation net losses of $44 million were reclassified from AOCI to other income, within our consolidated statement of operations. Such losses were previously considered in our impairment evaluation of the investment when we committed to a plan to sell the investment during the fourth quarter of 2013, and accordingly did not impact earnings for 2014.
[3]	Pre-tax amount was reclassified into cost of sales and operating expenses in the consolidated statements of operations. The related tax expense (benefit) was reclassified into income tax expense in the consolidated statements of operations.

Stockholders_Equity_Other_Comp1

Stockholders' Equity (Other Comprehensive Income (Loss), Tax) (Parentheticals) (Details) (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013	Mar. 31, 2012
Stockholders' Equity Note [Abstract]	'	'	'
Foreign currency translation adjustments arising during period, net of income tax expense (benefit) of nil, ($2) and $2	$0	($2)	$2
Reclassified to income statement, income tax expense of $24, nil and nil	24	0	0
Unrealized losses on cash flow hedges arising during period, tax benefit of nil, nil and nil	0	0	0
Net actuarial gain (loss) arising during period, net of income tax (benefit) of $16, ($22) and ($18)	16	-22	-18
Amortization of actuarial loss, prior service cost and transition obligation, net of income tax (benefit) of $12, $12 and ($9)	12	12	9
Foreign currency translation adjustments, net of income tax expense of nil, nil and nil	0	0	0
Reclassified to income statement, income tax expense of $1, nil and nil	$1	$0	$0

Stockholders_Equity_Changes_in

Stockholders' Equity (Changes in Accumulated Other Comprehensive Income by Component) (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2014		Mar. 31, 2013		Mar. 31, 2012
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'		'		'
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Gain (Loss) Arising During Period, Net of Tax	$9	[1]	($52)	[1]	($56)	[1]
Reclassified to income statement, net of income tax expense of $24, nil and nil (2)	44	[2]	0	[2]	0	[2]
Accumulated Other Comprehensive Income (Loss), Net of Tax, Beginning Balance	-65		'		'
Other comprehensive income (loss)	'		-70		-82
Accumulated Other Comprehensive Income (Loss), Net of Tax, Ending Balance	-3		-65		'
Parent Company [Member]	'		'		'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'		'		'
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Gain (Loss) Arising During Period, Net of Tax	-12		-52		'
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, Net of Tax, Portion Attributable to Parent	32		-52		'
Foreign currency, beginning balance	136		188		'
Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, Net of Tax, Portion Attributable to Parent	-6		0		'
Reclassified to income statement, net of income tax expense of $24, nil and nil (2)	44		'		'
Foreign currency, ending balance	168		136		'
Unrealized gains (losses) on derivative instruments, beginning balance	-5		-5		'
Unrealized losses on cash flow hedges arising during period, net of income tax benefit of nil, nil and nil	-6		0		'
Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI on Derivatives, Net of Tax	0		'		'
Other Comprehensive (Income) Loss, Reclassification Adjustment from AOCI, Pension and Other Postretirement Benefit Plans, Tax	1		'		'
Other Comprehensive (Income) Loss, Pension and Other Postretirement Benefit Plans, Adjustment, Net of Tax, Portion Attributable to Parent	36		-18		'
Unrealized gains (losses) on derivative instruments, ending balance	-11		-5		'
Unrealized net loss and other components of benefit plans, net of tax, beginning balance	-196		-178		'
Other Comprehensive Income Translation Impact On Pension Plans, Net Of Tax	35		-18		'
Unrealized net loss and other components of benefit plans, net of tax, ending balance	-160		-196		'
Accumulated Other Comprehensive Income (Loss), Net of Tax, Beginning Balance	-65		5		'
Other Comprehensive Income (Loss), Excluding Amount Reclassified to Earnings, Net of Tax, Portion Attributable To Parent	17		-70		'
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	45		'		'
Other comprehensive income (loss)	62		-70		'
Accumulated Other Comprehensive Income (Loss), Net of Tax, Ending Balance	($3)		($65)		'
[1]	The 2014 amounts include net foreign currency translation gain of $21 million attributable to noncontrolling interests.
[2]	As a result of our sale of our 49% equity interest in Nadro, foreign currency translation net losses of $44 million were reclassified from AOCI to other income, within our consolidated statement of operations. Such losses were previously considered in our impairment evaluation of the investment when we committed to a plan to sell the investment during the fourth quarter of 2013, and accordingly did not impact earnings for 2014.

Related_Party_Balances_and_Tra1

Related Party Balances and Transactions (Narrative) (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013	Mar. 31, 2012
Related Party Transaction [Line Items]	'	'	'
Equity-held investment rental expense	$0	$0	$10

Segments_of_Business_Narrative

Segments of Business (Narrative) (Details) (Distribution Solutions [Member])	12 Months Ended			1 Months Ended
	Mar. 31, 2014	Mar. 31, 2013	Mar. 31, 2012	Sep. 30, 2013
				Nadro [Member]
Segment Reporting Information [Line Items]	'	'	'	'
Subsidiary or Equity Method Investee, Cumulative Percentage Ownership after All Transactions	'	'	'	49.00%
Percentage of revenue derived from services for Distribution Solutions segment	'less than 2%	'less than 2%	'less than 2%	'

Segments_of_Business_Schedule_

Segments of Business (Schedule Of Segment Information) (Details) (USD $)

3 Months Ended

12 Months Ended

In Millions, unless otherwise specified

Mar. 31, 2014

Dec. 31, 2013

Sep. 30, 2013

Jun. 30, 2013

Mar. 31, 2013

Dec. 31, 2012

Sep. 30, 2012

Jun. 30, 2012

Mar. 31, 2014

Mar. 31, 2013

Mar. 31, 2012

Segment Reporting Information [Line Items]

'

'

'

'

'

'

'

'

'

'

'

Segment Reporting Revenue From External Customers

$38,141

$34,306

$32,954

$32,208

$30,516

$31,099

$29,755

$30,699

$137,609

[1]

$122,069

[1]

$122,321

[1]

Operating Income

'

'

'

'

'

'

'

'

2,367

2,325

2,124

Income From Continuing Operations Before Income Taxes

'

'

'

'

'

'

'

'

2,096

1,928

1,893

Interest Expense

'

'

'

'

'

'

'

'

-303

-240

-251

Depreciation and amortization

'

'

'

'

'

'

'

'

704

[2]

530

[2]

493

[2]

Expenditures for long-lived assets

'

'

'

'

'

'

'

'

274

[3]

232

[3]

221

[3]

Segment Reporting Revenue By Country

38,141

34,306

32,954

32,208

30,516

31,099

29,755

30,699

137,609

[1]

122,069

[1]

122,321

[1]

United States

'

'

'

'

'

'

'

'

'

'

'

Segment Reporting Information [Line Items]

'

'

'

'

'

'

'

'

'

'

'

Segment Reporting Revenue From External Customers

'

'

'

'

'

'

'

'

122,426

[1]

112,109

[1]

112,051

[1]

Segment Reporting Revenue By Country

'

'

'

'

'

'

'

'

122,426

[1]

112,109

[1]

112,051

[1]

Other [Member]

'

'

'

'

'

'

'

'

'

'

'

Segment Reporting Information [Line Items]

'

'

'

'

'

'

'

'

'

'

'

Segment Reporting Revenue From External Customers

'

'

'

'

'

'

'

'

15,183

[1]

9,960

[1]

10,270

[1]

Segment Reporting Revenue By Country

'

'

'

'

'

'

'

'

15,183

[1]

9,960

[1]

10,270

[1]

North America Distribution And Services [Member]

'

'

'

'

'

'

'

'

'

'

'

Segment Reporting Information [Line Items]

'

'

'

'

'

'

'

'

'

'

'

Segment Reporting Revenue From External Customers

'

'

'

'

'

'

'

'

123,930

[4]

115,443

[4]

116,279

[4]

Segment Reporting Revenue By Country

'

'

'

'

'

'

'

'

123,930

[4]

115,443

[4]

116,279

[4]

International Distribution and Services [Member]

'

'

'

'

'

'

'

'

'

'

'

Segment Reporting Information [Line Items]

'

'

'

'

'

'

'

'

'

'

'

Segment Reporting Revenue From External Customers

'

'

'

'

'

'

'

'

4,848

[4]

0

[4]

0

[4]

Segment Reporting Revenue By Country

'

'

'

'

'

'

'

'

4,848

[4]

0

[4]

0

[4]

Distribution Solutions [Member]

'

'

'

'

'

'

'

'

'

'

'

Segment Reporting Information [Line Items]

'

'

'

'

'

'

'

'

'

'

'

Segment Reporting Revenue From External Customers

'

'

'

'

'

'

'

'

134,426

[4]

119,046

[4]

119,424

[4]

Operating Income

'

'

'

'

'

'

'

'

2,461

2,195

2,219

Depreciation and amortization

'

'

'

'

'

'

'

'

448

[2]

265

[2]

224

[2]

Expenditures for long-lived assets

'

'

'

'

'

'

'

'

180

[3]

163

[3]

175

[3]

Segment Reporting Revenue By Country

'

'

'

'

'

'

'

'

134,426

[4]

119,046

[4]

119,424

[4]

Distribution Solutions - Medical Surgical Distribution And Services [Member]

'

'

'

'

'

'

'

'

'

'

'

Segment Reporting Information [Line Items]

'

'

'

'

'

'

'

'

'

'

'

Segment Reporting Revenue From External Customers

'

'

'

'

'

'

'

'

5,648

[4]

3,603

[4]

3,145

[4]

Segment Reporting Revenue By Country

'

'

'

'

'

'

'

'

5,648

[4]

3,603

[4]

3,145

[4]

Technology Solutions [Member]

'

'

'

'

'

'

'

'

'

'

'

Segment Reporting Information [Line Items]

'

'

'

'

'

'

'

'

'

'

'

Segment Reporting Revenue From External Customers

'

'

'

'

'

'

'

'

3,183

3,023

2,897

Operating Income

'

'

'

'

'

'

'

'

387

308

338

Depreciation and amortization

'

'

'

'

'

'

'

'

136

[2]

145

[2]

152

[2]

Expenditures for long-lived assets

'

'

'

'

'

'

'

'

42

[3]

28

[3]

18

[3]

Segment Reporting Revenue By Country

'

'

'

'

'

'

'

'

3,183

3,023

2,897

Corporate [Member]

'

'

'

'

'

'

'

'

'

'

'

Segment Reporting Information [Line Items]

'

'

'

'

'

'

'

'

'

'

'

Operating Income

'

'

'

'

'

'

'

'

-449

-335

-413

Depreciation and amortization

'

'

'

'

'

'

'

'

120

[2]

120

[2]

117

[2]

Expenditures for long-lived assets

'

'

'

'

'

'

'

'

52

[3]

41

[3]

28

[3]

Operating Segments [Member]

'

'

'

'

'

'

'

'

'

'

'

Segment Reporting Information [Line Items]

'

'

'

'

'

'

'

'

'

'

'

Income From Continuing Operations Before Income Taxes

'

'

'

'

'

'

'

'

$2,848

$2,503

$2,557

[1]

Net revenues were attributed to geographic areas based on the customersb shipment locations.

[2]

Amounts primarily include amortization of acquired intangible assets purchased in connection with acquisitions, capitalized software held for sale and capitalized software for internal use.

[3]

Long-lived assets consist of property, plant and equipment.

[4]

Revenues derived from services represent less than 2% of this segmentbs total revenues.

Segments_of_Business_Segment_A

Segments of Business (Segment Assets and Property, Plant and Equipment, Net by Geographica Ares) (Details) (USD $)	Mar. 31, 2014	Mar. 31, 2013	Mar. 31, 2012	Mar. 31, 2011
In Millions, unless otherwise specified
Segment Reporting Information [Line Items]	'	'	'	'
Assets	$51,759	$34,786	'	'
Cash and cash equivalents	4,193	2,456	3,149	3,612
Total Property, Plant and Equipment, Net	2,222	1,321	'	'
United States	'	'	'	'
Segment Reporting Information [Line Items]	'	'	'	'
Total Property, Plant and Equipment, Net	1,246	1,205	'	'
Other [Member]	'	'	'	'
Segment Reporting Information [Line Items]	'	'	'	'
Total Property, Plant and Equipment, Net	976	116	'	'
Distribution Solutions [Member]	'	'	'	'
Segment Reporting Information [Line Items]	'	'	'	'
Assets	42,758	27,307	'	'
Technology Solutions [Member]	'	'	'	'
Segment Reporting Information [Line Items]	'	'	'	'
Assets	3,324	3,829	'	'
Operating Segments [Member]	'	'	'	'
Segment Reporting Information [Line Items]	'	'	'	'
Assets	46,082	31,136	'	'
Total Property, Plant and Equipment, Net	2,222	1,321	'	'
Corporate [Member]	'	'	'	'
Segment Reporting Information [Line Items]	'	'	'	'
Other	$1,484	$1,194	'	'

Quarterly_Financial_Informatio2

Quarterly Financial Information (Unaudited) (Narrrative) (Details) (USD $)

12 Months Ended

3 Months Ended

12 Months Ended

3 Months Ended

12 Months Ended

3 Months Ended

12 Months Ended

3 Months Ended

In Millions, unless otherwise specified

Mar. 31, 2014

Mar. 31, 2013

Mar. 31, 2012

Jun. 30, 2012

Mar. 31, 2014

Dec. 31, 2013

Sep. 30, 2013

Mar. 31, 2013

Mar. 31, 2013

Mar. 31, 2014

Mar. 31, 2013

Dec. 31, 2013

Dec. 31, 2013

Mar. 31, 2013

Mar. 31, 2013

Dec. 31, 2012

Mar. 31, 2014

Mar. 31, 2013

Corporate Headquarters [Member]

Distribution Solutions [Member]

Distribution Solutions [Member]

Distribution Solutions [Member]

Distribution Solutions [Member]

Technology Solutions [Member]

Technology Solutions [Member]

Technology Solutions [Member]

International Technology [Member]

Canada Revenue Agency Assessments [Member]

Nadro [Member]

Nadro [Member]

RAMQ [Member]

Cost of Sales [Member]

Cost of Sales [Member]

Distribution Solutions [Member]

Distribution Solutions [Member]

Technology Solutions [Member]

Quarterly Financial Information [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Net LIFO expense

$311

$13

$11

'

$125

$142

$44

'

'

'

'

'

'

'

'

'

'

'

Business Combination, Inventory Step-Up Fair Value Pre-tax Charge

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

50

'

Business Combination Inventory Step-Up Fair Value After-tax Charge

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

28

'

Income Tax Expense Discrete Items

-94

29

66

'

'

'

'

'

'

'

'

'

122

'

'

'

'

'

Goodwill and Intangible Asset Impairment

'

'

'

'

'

'

'

'

46

57

46

80

'

'

'

'

'

'

Gain on business combination

0

81

0

81

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Litigation charges

68

72

149

'

'

'

'

'

'

'

'

'

'

'

'

40

'

'

Impairment of an equity investment

0

191

0

'

'

'

'

'

'

'

'

'

'

191

191

'

'

'

Goodwill, Impairment Loss

'

36

'

'

'

'

'

0

36

'

36

'

'

'

'

'

'

'

Capitalized Computer Software, Impairments

$12

$10

$0

'

'

'

'

'

'

'

'

'

'

'

'

'

'

$10

Quarterly_Financial_Informatio3

Quarterly Financial Information (Unaudited) (Schedule Of Quarterly Financial Information) (Details) (USD $)	3 Months Ended																12 Months Ended
In Millions, except Per Share data, unless otherwise specified	Mar. 31, 2014		Dec. 31, 2013		Sep. 30, 2013		Jun. 30, 2013		Mar. 31, 2013		Dec. 31, 2012		Sep. 30, 2012		Jun. 30, 2012		Mar. 31, 2014		Mar. 31, 2013		Mar. 31, 2012
Quarterly Financial Information [Line Items]	'		'		'		'		'		'		'		'		'		'		'
Revenues	$38,141		$34,306		$32,954		$32,208		$30,516		$31,099		$29,755		$30,699		$137,609	[1]	$122,069	[1]	$122,321	[1]
Gross profit	2,540	[2]	1,840	[2]	2,009	[2]	1,920	[2]	1,959		1,645		1,683		1,561		8,309		6,848		6,402
Income from continuing operations	362	[2],[3]	156	[2],[3]	416	[2],[3]	420	[2],[3]	263	[4],[5],[6]	306	[4],[5],[6]	399	[4],[5],[6]	379	[4],[5],[6]	1,354		1,347		1,379
Income (Loss) from Discontinued Operations, Net of Tax	4	[7]	-92	[7]	-12	[7]	4	[7]	-4		-8		2		1		-96		-9		24
Net Income	366		64		404		424		259		298		401		380		1,258		1,338		1,403
Net Income (Loss) Attributable to Noncontrolling Interest	5	[8]	0	[8]	0	[8]	0	[8]	0		0		0		0		5		0		0
Net Income Attributable to McKesson	$371		$64		$404		$424		$259		$298		$401		$380		$1,263		$1,338		$1,403
Earnings (Loss) Per Common Share Attributable to McKesson	'		'		'		'		'		'		'		'		'		'		'
Diluted	$1.58		$0.28		$1.74		$1.83		$1.10		$1.24		$1.67		$1.58		$5.41	[9]	$5.59	[9]	$5.59	[9]
Continuing operations	$1.56		$0.67		$1.79		$1.81		$1.11		$1.27		$1.66		$1.58		$5.83	[9]	$5.62	[9]	$5.49	[9]
Discontinued operations	$0.02		($0.39)		($0.05)		$0.02		($0.01)		($0.03)		$0.01		$0		($0.42)	[9]	($0.03)	[9]	$0.10	[9]
Basic	$1.61		$0.28		$1.76		$1.86		$1.12		$1.27		$1.70		$1.61		$5.51	[9]	$5.71	[9]	$5.70	[9]
Continuing operations	$1.59		$0.68		$1.82		$1.84		$1.13		$1.30		$1.69		$1.61		$5.93	[9]	$5.74	[9]	$5.60	[9]
Discontinued operations	$0.02		($0.40)		($0.06)		$0.02		($0.01)		($0.03)		$0.01		$0		($0.42)	[9]	($0.03)	[9]	$0.10	[9]
[1]	Net revenues were attributed to geographic areas based on the customersb shipment locations.
[2]	Financial results for the second, third and fourth quarters of 2014 includes pre-tax charges in our Distribution Solutions segment related to our LIFO method of accounting for inventories of $44 million, $142 million and $125B million, which were recorded in cost of sales. Fourth quarter 2014 also includes a $50B million pre-tax charge to cost of sales within our Distribution Solutions segment representing the reversal of a step-up to fair value of Celesiobs inventory at the date of acquisition. Our after-tax portion of this charge (after allocation to noncontrolling interests), was $28 million
[3]	Financial results for the third quarter of 2014 include an income tax charge of $122 million relating to a litigation with the Canadian Revenue Agency.
[4]	Financial results for the first quarter of 2013 include an $81 million pre-tax gain on business combination, which was recorded as a reduction to operating expenses within our Corporate segment.
[5]	Financial results for the fourth quarter of 2013 include a pre-tax impairment charge for an equity investment of $191 million recorded in other income, net within our Distribution Solutions segment. Financial results for the fourth quarter of 2013 also include $46 million of pre-tax impairment charges recorded in our Technology Solutions segment of which $36 million was recorded in operating expenses and $10B million was recorded in cost of sales.
[6]	Financial results for the third quarter of 2013 include a $40 million pre-tax charge for a legal dispute in our Canadian business which was recorded in operating expenses within our Distribution Solutions segment.
[7]	Financial results for the third quarter of 2014, include an $80 million of after-tax impairment charge related to our International Technology Business.
[8]	Primarily represents the noncontrolling shareholdersb portion of net loss from Celesio.
[9]	Certain computations may reflect rounding adjustments.

Supplementary_Consolidated_Fin1

Supplementary Consolidated Financial Statement Schedule Valuation And Qualifying Accounts (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2014		Mar. 31, 2013		Mar. 31, 2012
Valuation and Qualifying Accounts Disclosure [Line Items]	'		'		'
Balance at Beginning of Year	$136	[1]	$125	[1]	$140
Charged to Costs and Expense	38		32		35
Charged to Other Accounts	-1	[2]	17	[2]	0	[2]
Deductions From Allowance Accounts	-37	[3]	-38	[3]	-50	[3]
Balance at End of Year	136	[1]	136	[1]	125	[1]
Allowance for Doubtful Accounts [Member]	'		'		'
Valuation and Qualifying Accounts Disclosure [Line Items]	'		'		'
Balance at Beginning of Year	121	[1]	111	[1]	124
Charged to Costs and Expense	38		28		30
Charged to Other Accounts	-12	[2]	16	[2]	0	[2]
Deductions From Allowance Accounts	-34	[3]	-34	[3]	-43	[3]
Balance at End of Year	113	[1]	121	[1]	111	[1]
Other Allowances [Member]	'		'		'
Valuation and Qualifying Accounts Disclosure [Line Items]	'		'		'
Balance at Beginning of Year	15	[1]	14	[1]	16
Charged to Costs and Expense	0		4		5
Charged to Other Accounts	11	[2]	1	[2]	0	[2]
Deductions From Allowance Accounts	-3	[3]	-4	[3]	-7	[3]
Balance at End of Year	23	[1]	15	[1]	14	[1]
Written Off [Member]	'		'		'
Valuation and Qualifying Accounts Disclosure [Line Items]	'		'		'
Deductions From Allowance Accounts	-39		-38		-44
Credited To Other Accounts [Member]	'		'		'
Valuation and Qualifying Accounts Disclosure [Line Items]	'		'		'
Deductions From Allowance Accounts	2		0		-6
Amounts Shown As Deductions From Current And Non-Current Receivables [Member]	'		'		'
Valuation and Qualifying Accounts Disclosure [Line Items]	'		'		'
Balance at End of Year	$136		$136		$125
[1]	Amounts shown as deductions from current and non - current receivables [$0], $136, $125.
[2]	Primarily represents reclassifications from other balance sheet accounts.
[3]	Deductions:Written off - [($0)], ($38), ($44)Credited to other accounts - [($0)], ($0), ($6)Total - [($0)], ($38), ($50)