Cencora (COR) 10-K 24 Nov 15 2015 FY Annual report Financial data

Document and Entity Information

Document and Entity Information - USD ($)	12 Months Ended
	Sep. 30, 2015	Oct. 31, 2015	Mar. 31, 2015
Document and Entity Information [Abstract]
Entity Registrant Name	AMERISOURCEBERGEN CORP
Entity Central Index Key	1,140,859
Document Type	10-K
Document Period End Date	Sep. 30, 2015
Amendment Flag	false
Document Fiscal Year Focus	2,015
Document Fiscal Period Focus	FY
Current Fiscal Year End Date	--09-30
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Filer Category	Large Accelerated Filer
Entity Public Float			$ 20,376,106,134
Entity Common Stock, Shares Outstanding		205,632,943
Trading Symbol	abc

CONSOLIDATED BALANCE SHEETS

CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Sep. 30, 2015	Sep. 30, 2014
Current assets:
Cash and cash equivalents	$ 2,167,442	$ 1,808,513
Accounts receivable, less allowances for returns and doubtful accounts: 2015 - $899,764; 2014 - $998,383	8,222,951	6,312,883
Merchandise inventories	9,755,094	8,593,852
Prepaid expenses and other	189,001	84,957
Total current assets	20,334,488	16,800,205
Property and equipment, at cost:
Land	39,499	37,538
Buildings and improvements	413,854	359,037
Machinery, equipment and other	1,449,545	1,295,854
Total property and equipment	1,902,898	1,692,429
Less accumulated depreciation	(923,647)	(792,847)
Property and equipment, net	979,251	899,582
Goodwill and other intangible assets	6,123,944	3,481,744
Other assets	298,474	350,652
TOTAL ASSETS	27,736,157	21,532,183
Current liabilities:
Accounts payable	20,886,439	15,592,834
Accrued expenses and other	679,309	561,863
Deferred income taxes	1,135,017	1,095,463
Total current liabilities	22,700,765	17,250,160
Long-term debt	3,493,048	1,995,632
Deferred income taxes	819,188	241,205
Other liabilities	89,636	88,287
Stockholders' equity:
Common stock, $0.01 par value - authorized, issued and outstanding: 600,000,000 shares, 274,991,824 shares and 206,891,873 shares at September 30, 2015, respectively, and 600,000,000 shares, 271,126,753 shares and 221,908,650 shares at September 30, 2014, respectively	2,750	2,711
Additional paid-in capital	3,736,477	2,749,185
Retained earnings	1,181,623	1,570,429
Accumulated other comprehensive loss	(136,333)	(52,046)
Treasury stock, at cost: 2015 - 68,099,951 shares; 2014 - 49,218,103 shares	(4,150,997)	(2,313,380)
Total stockholders' equity	633,520	1,956,899
TOTAL LIABILITIES AND STOCKHOLDERS' EQUITY	$ 27,736,157	$ 21,532,183

CONSOLIDATED BALANCE SHEETS (Pa

CONSOLIDATED BALANCE SHEETS (Parenthetical) - USD ($) $ in Thousands	Sep. 30, 2015	Sep. 30, 2014
Current assets:
Allowances for returns and doubtful accounts	$ 899,764	$ 998,383
Stockholders' equity:
Common stock, par value	$ 0.01	$ 0.01
Common stock, shares authorized	600,000,000	600,000,000
Common stock, shares issued	274,991,824	271,126,753
Common stock, shares outstanding	206,891,873	221,908,650
Treasury stock, shares held	68,099,951	49,218,103

CONSOLIDATED STATEMENTS OF OPER

CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2013
CONSOLIDATED STATEMENTS OF OPERATIONS
Revenue	$ 135,961,803	$ 119,569,127	$ 87,959,167
Cost of goods sold	132,432,490	116,586,761	85,451,348
Gross profit	3,529,313	2,982,366	2,507,819
Operating expenses:
Distribution, selling and administrative	1,918,045	1,587,261	1,333,712
Depreciation	186,789	159,328	135,047
Amortization	56,491	25,962	27,139
Warrants	912,724	422,739	90,055
Employee severance, litigation and other	37,894	8,192	23,467
Operating income	417,370	778,884	898,399
Other loss (income)	13,598	(4,360)	44
Impairment charge on equity investment	30,622	0	0
Interest expense, net	99,001	76,862	73,897
Loss on early retirement of debt	0	32,954	0
Income from continuing operations before income taxes	274,149	673,428	824,458
Income taxes	409,036	389,398	331,023
(Loss) income from continuing operations	(134,887)	284,030	493,435
Loss from discontinued operations, net of income tax expense of $0 and $9,638 for fiscal 2014 and 2013, respectively	0	(7,546)	(59,728)
Net (loss) income	$ (134,887)	$ 276,484	$ 433,707
Basic earnings per share:
Continuing operations	$ (0.62)	$ 1.25	$ 2.14
Discontinued operations	0	(0.03)	(0.26)
Total	(0.62)	1.22	1.88
Diluted earnings per share:
Continuing operations	(0.62)	1.21	2.10
Discontinued operations	0	(0.03)	(0.25)
Rounding	0	(0.01)	(0.01)
Total	$ (0.62)	$ 1.17	$ 1.84
Weighted average common shares outstanding:
Basic	217,786	227,367	231,067
Diluted	217,786	235,405	235,345

CONSOLIDATED STATEMENTS OF OPE5

CONSOLIDATED STATEMENTS OF OPERATIONS (Parenthetical) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2014	Sep. 30, 2013
CONSOLIDATED STATEMENTS OF OPERATIONS
Income tax expense	$ 0	$ 9,638

CONSOLIDATED STATEMENTS OF COMP

CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2013
CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME
Net (loss) income	$ (134,887)	$ 276,484	$ 433,707
Other comprehensive income (loss):
Net change in foreign currency translation adjustments	(84,142)	(18,544)	(14,181)
Benefit plan funded status adjustments net of tax of $1,055, $1,361, and $7,992, respectively	(4,607)	2,400	11,216
Other	4,462	(419)	139
Total other comprehensive loss	(84,287)	(16,563)	(2,826)
Total comprehensive (loss) income	$ (219,174)	$ 259,921	$ 430,881

CONSOLIDATED STATEMENTS OF COM7

CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (Parenthetical) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2013
CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME
Other Comprehensive Income Defined Benefit Plans Tax	$ 1,055	$ 1,361	$ 7,992

CONSOLIDATED STATEMENTS OF CHAN

CONSOLIDATED STATEMENTS OF CHANGES IN STOCKHOLDERS' EQUITY - USD ($) $ in Thousands	Common Stock	Additional Paid-in Capital	Retained Earnings	Accumulated Other Comprehensive Loss	Treasury Stock	Total
Total stockholders' equity at the beginning of the period at Sep. 30, 2012	$ 2,625	$ 2,252,470	$ 1,270,423	$ (32,657)	$ (1,038,019)	$ 2,454,842
Increase (decrease) in stockholders' equity
Net (loss) income			433,707			433,707
Other comprehensive loss				(2,826)		(2,826)
Cash dividends, $0.84 per share, $0.94 per share, and $1.16 per share, respectively, for fiscal years ended September 30, 2013, 2014 and 2015			(195,716)			(195,716)
Exercise of stock options	50	114,441				114,491
Excess tax benefit from exercise of stock options		41,222				41,222
Share-based compensation expense		36,751				36,751
Settlement of accelerated stock repurchase agreement		(10,312)				(10,312)
Common stock purchases for employee stock purchase plan		(260)				(260)
Warrant expense		90,055				90,055
Purchases of call options		(163,372)				(163,372)
Purchases of common stock					(473,864)	(473,864)
Employee tax withholdings related to restricted share vesting					(4,973)	(4,973)
Other	3	(3)				0
Total stockholders' equity at the end of the period at Sep. 30, 2013	2,678	2,360,992	1,508,414	(35,483)	(1,516,856)	2,319,745
Increase (decrease) in stockholders' equity
Net (loss) income			276,484			276,484
Other comprehensive loss				(16,563)		(16,563)
Cash dividends, $0.84 per share, $0.94 per share, and $1.16 per share, respectively, for fiscal years ended September 30, 2013, 2014 and 2015			(214,469)			(214,469)
Exercise of stock options	30	81,535				81,565
Excess tax benefit from exercise of stock options		46,341				46,341
Share-based compensation expense		43,107				43,107
Common stock purchases for employee stock purchase plan		(206)				(206)
Warrant expense		422,739				422,739
Purchases of call options		(205,320)				(205,320)
Purchases of common stock					(789,927)	(789,927)
Employee tax withholdings related to restricted share vesting					(6,597)	(6,597)
Other	3	(3)				0
Total stockholders' equity at the end of the period at Sep. 30, 2014	2,711	2,749,185	1,570,429	(52,046)	(2,313,380)	1,956,899
Increase (decrease) in stockholders' equity
Net (loss) income			(134,887)			(134,887)
Other comprehensive loss				(84,287)		(84,287)
Cash dividends, $0.84 per share, $0.94 per share, and $1.16 per share, respectively, for fiscal years ended September 30, 2013, 2014 and 2015			(253,919)			(253,919)
Exercise of stock options	36	105,839				105,875
Excess tax benefit from exercise of stock options		88,116				88,116
Share-based compensation expense		60,944				60,944
Common stock purchases for employee stock purchase plan		(328)				(328)
Warrant expense		912,724				912,724
Purchases of call options		(180,000)				(180,000)
Purchases of common stock					(1,823,106)	(1,823,106)
Employee tax withholdings related to restricted share vesting					(14,511)	(14,511)
Other	3	(3)				0
Total stockholders' equity at the end of the period at Sep. 30, 2015	$ 2,750	$ 3,736,477	$ 1,181,623	$ (136,333)	$ (4,150,997)	$ 633,520

CONSOLIDATED STATEMENTS OF CHA9

CONSOLIDATED STATEMENTS OF CHANGES IN STOCKHOLDERS' EQUITY (Parenthetical) - $ / shares	12 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2013
CONSOLIDATED STATEMENTS OF CHANGES IN STOCKHOLDERS EQUITY
Common Stock Dividends Per Share Cash Paid	$ 1.16	$ 0.94	$ 0.84

CONSOLIDATED STATEMENTS OF CASH

CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2013
OPERATING ACTIVITIES
Net (loss) income	$ (134,887)	$ 276,484	$ 433,707
Loss from discontinued operations	0	7,546	59,728
(Loss) income from continuing operations	(134,887)	284,030	493,435
Adjustments to reconcile (loss) income from continuing operations to net cash provided by operating activities:
Depreciation, including amounts charged to cost of goods sold	187,935	162,089	138,690
Amortization, including amounts charged to interest expense	61,665	30,644	32,103
Provision for doubtful accounts	8,119	26,634	20,118
Provision for deferred income taxes	22,733	39,312	25,573
Warrant expense	912,724	422,739	90,055
Share-based compensation	60,944	43,107	36,275
Loss on sale of business	12,953	0	0
Impairment charge on equity investment	30,622	0	0
Loss on early retirement of debt	0	32,954	0
Other	(11,604)	(6,539)	3,727
Changes in operating assets and liabilities, excluding the effects of acquisitions and divestitures :
Accounts receivable	(1,478,793)	(938,286)	(2,312,518)
Merchandise inventories	(836,382)	(956,506)	(1,486,572)
Prepaid expenses and other assets	(37,131)	21,107	(169,745)
Accounts payable, accrued expenses, and income taxes	5,125,914	2,317,589	3,818,288
Other liabilities	(4,433)	(8,175)	12,559
Net cash provided by operating activities - continuing operations	3,920,379	1,470,699	701,988
Net cash (used in) provided by operating activities-discontinued operations	0	(7,546)	86,137
NET CASH PROVIDED BY OPERATING ACTIVITIES	3,920,379	1,463,153	788,125
INVESTING ACTIVITIES
Capital expenditures	(231,585)	(264,457)	(202,450)
Cost of acquired companies, net of cash acquired	(2,633,412)	(9,103)	0
Cost of equity investments	0	(117,794)	0
Proceeds from sale of business	17,163	0	329,980
Purchases of investment securities available-for-sale	(86,214)	0	0
Other	2,883	7,199	1,402
Net cash (used in) provided by investing activities-continuing operations	(2,931,165)	(384,155)	128,932
Net cash used in investing activities-discontinued operations	0	0	(11,672)
NET CASH (USED IN) PROVIDED BY INVESTING ACTIVITIES	(2,931,165)	(384,155)	117,260
FINANCING ACTIVITIES
Long- term debt borrowings	1,996,390	1,097,927	0
Long-term debt repayments	(500,000)	(531,525)	0
Borrowings under revolving and securitization credit facilities	111,100	17,584,500	2,330,000
Repayments under revolving and securitization credit facilities	(111,100)	(17,584,500)	(2,330,000)
Purchases of common stock	(1,859,106)	(753,926)	(484,176)
Exercises of stock options, including excess tax benefits of $88,116, $46,341, and $41,222, in fiscal 2015, 2014, and 2013, respectively	193,991	127,906	155,713
Cash dividends on common stock	(253,919)	(214,469)	(195,716)
Purchases of call options	(180,000)	(211,397)	(157,295)
Debt issuance costs and other	(27,641)	(16,007)	(8,975)
Net cash used in financing activities-continuing operations	(630,285)	(501,491)	(690,449)
Net cash used in financing activities-discontinued operations	0	0	(50,538)
NET CASH USED IN FINANCING ACTIVITIES	(630,285)	(501,491)	(740,987)
INCREASE IN CASH AND CASH EQUIVALENTS	358,929	577,507	164,398
Cash and cash equivalents at beginning of year	1,808,513	1,231,006	1,066,608
CASH AND CASH EQUIVALENTS AT END OF YEAR	$ 2,167,442	$ 1,808,513	$ 1,231,006

CONSOLIDATED STATEMENTS OF CA11

CONSOLIDATED STATEMENTS OF CASH FLOWS (Parenthetical) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2013
FINANCING ACTIVITIES
Excess tax benefit from the exercise of stock options	$ 88,116	$ 46,341	$ 41,222

Summary of Significant Accounti

Summary of Significant Accounting Policies	12 Months Ended
	Sep. 30, 2015
Summary of Significant Accounting Policies [Abstract]
Significant Accounting Policies [Text Block]	Note 1. Summary of Significant Accounting Policies AmerisourceBergen Corporation (the "Company") is one of the largest global pharmaceutical sourcing and distribution services companies, helping both healthcare providers and pharmaceutical and biotech manufacturers improve patient access to products and enhance patient care. The Company delivers innovative programs and services designed to increase the effectiveness and efficiency of the pharmaceutical supply chain in both human and animal health. Basis of Presentation The accompanying consolidated financial statements include the accounts of the Company and its wholly-owned subsidiaries as of the dates and for the fiscal years indicated. All intercompany accounts and transactions have been eliminated in consolidation. The preparation of financial statements in conformity with U.S. generally accepted accounting principles requires management to make estimates and assumptions that affect amounts reported in the financial statements and accompanying notes. Actual amounts could differ from these estimated amounts due to uncertainties inherent in such estimates. Management periodically evaluates estimates used in the preparation of the financial statements for continued reasonableness. In May 2014, the Financial Accounting Standards Board issued Accounting Standards Update No. 2014-09, "Revenue from Contracts with Customers (Topic 606)" ("ASU 2014-09"). ASU 2014-09 supersedes the revenue recognition requirements in Accounting Standards Codification 605 — Revenue Recognition, and most industry-specific guidance throughout the Codification. ASU 2014-09 outlines a single comprehensive model for entities to use in accounting for revenue arising from contracts with customers. The standard's core principle is that a company should recognize revenue to depict the transfer of promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services. ASU 2014-09 was originally scheduled to be effective for annual reporting periods beginning after December 15, 2016, including interim periods within those reporting periods. In July 2015, the Financial Accounting Standards Board deferred the effective date of ASU 2014-09 by one year. Entities are permitted to adopt the standard as early as the original public entity effective date, and either full or modified retrospective application is required. The Company has not yet selected an adoption date or a transition method and is currently evaluating the impact of adopting this new accounting guidance. In April 2015, the Financial Accounting Standards Board issued Accounting Standards Update No. 2015-03, Interest — Imputation of Interest (Subtopic 835-30): Simplifying the Presentation of Debt Issuance Costs ("ASU 2015-03"). ASU 2015-03 is the result of the Financial Accounting Standards Board's simplification initiative intended to improve U.S. GAAP by reducing costs and complexity while maintaining or enhancing the usefulness of related financial statement information. ASU 2015-03 specifies that debt issuance costs related to a note shall be reported in the balance sheet as a direct reduction from the face amount of the note. ASU 2015-03 is effective for annual reporting periods beginning after December 15, 2015, and interim periods within those fiscal years. ASU 2015-03 will require the Company to reclassify its capitalized debt issuance costs currently recorded as assets on the consolidated condensed balance sheets. ASU 2015-03 will have no effect on the Company's results of operations or liquidity. As of September 30, 2015, there are no other recently issued accounting standards that will have a material impact on the Company's financial position or results of operation upon their adoption. Business Combinations The purchase price of an acquired company, including the fair value of contingent consideration, is allocated between tangible and intangible assets acquired and liabilities assumed from the acquired business based on their estimated fair values, with the residual of the purchase price recorded as goodwill. The results of operations of the acquired businesses are included in the Company's operating results from the dates of acquisition. Cash Equivalents The Company considers all highly liquid investments with original maturities of three months or less to be cash equivalents. The carrying value of cash equivalents approximates fair value. Concentrations of Credit Risk and Allowance for Doubtful Accounts The Company sells its merchandise inventories to a large number of customers in the healthcare industry that include institutional and retail healthcare providers. Institutional healthcare providers include acute care hospitals, health systems, mail order pharmacies, long-term care and other alternate care pharmacies and providers of pharmacy services to such facilities, and physician offices. Retail healthcare providers include national and regional retail drugstore chains, independent community pharmacies, pharmacy departments of supermarkets and mass merchandisers, and veterinarians. The financial condition of the Company's customers can be affected by changes in government reimbursement policies as well as by other economic pressures in the healthcare industry. The Company's trade accounts receivable are exposed to credit risk. The Company's largest customer in fiscal 2015, Walgreens Boots Alliance, Inc. ("WBA"), accounted for 30% of revenue and represented approximately 40% of accounts receivable, net as of September 30, 2015. Express Scripts, Inc., the Company's second largest customer in fiscal 2015, accounted for 16% of revenue and represented approximately 10% of accounts receivable, net as of September 30, 2015. The Company generally does not require collateral for trade receivables. In determining the appropriate allowance for doubtful accounts, the Company considers a combination of factors, such as the aging of trade receivables, industry trends, its customers' financial strength, credit standing, and payment and default history. Changes in these factors, among others, may lead to adjustments in the Company's allowance for doubtful accounts. The calculation of the required allowance requires judgment by Company management as to the impact of those and other factors on the ultimate realization of its trade receivables. Each of the Company's business units performs ongoing credit evaluations of its customers' financial condition and maintains reserves for probable bad debt losses based on historical experience and for specific credit problems when they arise. There were no significant changes to this process during the fiscal years ended September 30, 2015, 2014, and 2013 and bad debt expense was computed in a consistent manner during these periods. The bad debt expense for any period presented is equal to the changes in the period end allowance for doubtful accounts, net of write-offs, recoveries and other adjustments. The Company maintains cash and cash equivalents with several financial institutions. Deposits held with banks may exceed the amount of insurance provided on such deposits. These deposits may be redeemed upon demand, and are maintained with financial institutions with reputable credit, and, therefore, bear minimal credit risk. The Company seeks to mitigate such risks by monitoring the risk profiles of these counterparties. The Company also seeks to mitigate risk by monitoring the investment strategy of money market accounts that it is invested in, which are classified as cash equivalents. Contingencies Loss Contingencies: In the ordinary course of its business, the Company becomes involved in lawsuits, administrative proceedings, government subpoenas, and government investigations, including antitrust, commercial, environmental, product liability, intellectual property, regulatory, employment discrimination, and other matters. Significant damages or penalties may be sought from the Company in some matters, and some matters may require years for the Company to resolve. The Company records a liability when it is probable that a loss has been incurred and the amount is reasonably estimable. The Company also performs an assessment of the materiality of loss contingencies where a loss is either not probable or it is reasonably possible that a loss could be incurred in excess of amounts accrued. If a loss or an additional loss has at least a reasonable possibility of occurring and the impact on the financial statements would be material, the Company provides disclosure of the loss contingency in the footnotes to its financial statements. The Company reviews 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 the range of the loss can be made (see Note 13). Gain Contingencies: The Company records gain contingencies when they are realized. Gains from antitrust litigation settlements are realized upon the receipt of cash and recorded as a reduction to cost of goods sold because they represent a recovery of amounts historically paid to manufacturers to originally acquire the pharmaceuticals that were the subject of the antitrust litigation settlements (see Note 14). Derivative Financial Instruments The Company records all derivative financial instruments on the balance sheet at fair value and complies with established criteria for designation and effectiveness of hedging relationships. The Company's policy prohibits it from entering into derivative financial instruments for speculative or trading purposes. The Company had one foreign currency denominated contract outstanding that hedges the foreign currency exchange risk of a C$46.9 million note outstanding as of September 30, 2015. Equity Method Investments The Company uses the equity method of accounting for its investments in entities in which it has significant influence; generally, this represents an ownership interest of between 20% and 50% (see Note 3). Declines in value that are determined to be other-than-temporary are recorded as impairment charges as a component of earnings in the period in which that determination is made. The Company recorded an impairment charge of $30.6 million in fiscal 2015 related to its minority interest in a pharmaceutical wholesaler in Brazil. The impairment charge was based on the determination by the Company that the decline in the pharmaceutical wholesaler's stock price from the date on which the investment was made to September 30, 2015 was other-than-temporary. There were no impairment charges on equity investments in fiscal 2014 or 2013. Foreign Currency The functional currency of the Company's foreign operations is generally the applicable local currency. Assets and liabilities are translated into U.S. dollars using the current exchange rates in effect at the balance sheet date, while revenues and expenses are translated at the weighted average exchange rates for the period. The resulting translation adjustments are recorded as a component of accumulated other comprehensive loss within stockholders' equity. Goodwill and Other Intangible Assets Goodwill and other intangible assets with indefinite lives, primarily trademarks and trade names, are not amortized; rather, they are tested for impairment at least annually. For the purpose of these impairment tests, the Company can elect to perform a qualitative analysis to determine if it is more likely than not that the fair values of its reporting units and indefinite lived intangible assets are less than the respective carrying values of those reporting units and indefinite lived intangible assets. The Company elected to bypass performing the qualitative screen and went directly to performing the first step quantitative analysis of the goodwill and indefinite lived intangible asset impairment tests in the current year. The Company may elect to perform the qualitative analysis in future periods. The first step in the quantitative process for the goodwill impairment test is to compare the carrying amount of the reporting unit's net assets to the fair value of the reporting unit. If the fair value exceeds the carrying value, no further evaluation is required and no impairment loss is recognized. If the carrying amount exceeds the fair value, then the second step must be completed, which involves allocating the fair value of the reporting unit to each asset and liability, with the excess being implied goodwill. An impairment loss occurs if the amount of the recorded goodwill exceeds the implied goodwill. The Company would be required to record any such impairment losses. The Company identifies its reporting units at the operating segment level. Generally, goodwill arises from acquisitions of specific operating companies and is assigned to the reporting unit in which a particular operating company resides. The Company utilizes a combination of income and market-based approaches to value its reporting units. The income approach to valuation relies on a discounted cash flow analysis to determine the fair value of each reporting unit, which considers forecasted cash flows discounted at an appropriate discount rate. The Company believes that market participants would use a discounted cash flow analysis to determine the fair value of its reporting units in a sale transaction. The annual goodwill impairment test requires the Company to make a number of assumptions and estimates concerning future levels of revenue growth, operating margins, depreciation, amortization and working capital requirements, which are based upon the Company's long-range plan. The discount rate is an estimate of the overall after-tax rate of return required by a market participant whose weighted average cost of capital includes both equity and debt, including a risk premium. While the Company uses the best available information to prepare its cash flow and discount rate assumptions, actual future cash flows or market conditions could differ significantly resulting in future impairment charges related to recorded goodwill balances. While there are always changes in assumptions to reflect changing business and market conditions, the Company's overall methodology and the population of assumptions used have remained unchanged. The impairment test for indefinite-lived intangibles other than goodwill (primarily trademarks and trade names) consists of a comparison of the fair value of the indefinite-lived intangible asset to the carrying value of the asset as of the impairment testing date. The Company estimates the fair value of its indefinite-lived intangibles using the relief from royalty method. The Company believes the relief from royalty method is a widely used valuation technique for such assets. The fair value derived from the relief from royalty method is measured as the discounted cash flow savings realized from owning such trademarks and trade names and not having to pay a royalty for their use. The Company completed its required annual impairment tests relating to goodwill and other intangible assets in the fiscal years ended September 30, 2015, 2014, and 2013, and, as a result, determined that there were no impairments. Finite-lived intangible assets are amortized using the straight-line method over the estimated useful lives of the assets. Income Taxes The Company accounts for income taxes using a method that requires recognition of deferred tax assets and liabilities for expected future tax consequences of temporary differences that currently exist between tax bases and financial reporting bases of the Company's assets and liabilities (commonly known as the asset and liability method). In assessing the ability to realize deferred tax assets, the Company considers whether it is more likely than not that some portion or all of the deferred tax assets will not be realized. The Company recognizes the tax benefit from an uncertain tax position only if it is more likely than not that the tax position will be sustained upon examination by the taxing authorities, including resolutions of any related appeals or litigation processes, based on the technical merits of the position. Tax benefits associated with uncertain tax positions that have met the recognition criteria are measured and recorded based on the highest probable outcome that is more than 50% likely to be realized after full disclosure and resolution of a tax examination. Investment Securities Available-For-Sale All highly liquid investments with maturities of three months or less at the date of purchase are classified as cash equivalents. The Company's marketable debt securities have been classified and accounted for as available-for-sale. Management determines the appropriate classification of its investments at the time of purchase and reevaluates the classifications at each balance sheet date. The Company classifies its marketable debt securities as either short-term or long-term based on each instrument's underlying contractual maturity date. Marketable debt securities with maturities of 12 months or less are classified as short-term and marketable debt securities with maturities greater than 12 months are classified as long-term. The Company's marketable debt is carried at fair value, with unrealized gains and losses reported as a component of accumulated other comprehensive income in shareholders' equity, with the exception of unrealized losses believed to be other-than-temporary, which are reported in earnings in the current period. The cost of securities sold is based upon the specific identification method. As of September 30, 2015, the fair value of the Company's investment securities available-for-sale was $86.2 million, $50.8 million of which was within Prepaid Expenses and Other and $35.4 million of which was within Other Assets on the Company's consolidated balance sheets. The Company did not have any investment securities available-for-sale as of September 30, 2014. Manufacturer Incentives The Company accounts for fees and other incentives received from its suppliers, relating to the purchase or distribution of inventory, as a reduction to cost of goods sold. The Company considers these fees and other incentives to represent product discounts, and as a result, they are capitalized as product costs and relieved through cost of goods sold upon the sale of the related inventory. Merchandise Inventories Inventories are stated at the lower of cost or market. Cost for approximately 80% and 84% of the Company's inventories at September 30, 2015 and 2014, respectively, has been determined using the last-in, first-out (LIFO) method. If the Company had used the first-in, first-out (FIFO) method of inventory valuation, which approximates current replacement cost, inventories would have been approximately $1,424.6 million and $881.8 million higher than the amounts reported at September 30, 2015 and 2014, respectively. The Company recorded LIFO expense of $542.8 million, $348.1 million, and $277.0 million in fiscal 2015, 2014, and 2013, respectively. The annual LIFO provision is affected by changes in inventory quantities, product mix, and manufacturing pricing practices, which may be impacted by market and other external influences, many of which are difficult to predict. Changes to any of the above factors can have a material impact to the Company's annual LIFO provision. Property and Equipment Property and equipment are stated at cost and depreciated using the straight-line method over the estimated useful lives of the assets, which range from 3 to 40 years for buildings and improvements and from 3 to 10 years for machinery, equipment and other. The costs of repairs and maintenance are charged to expense as incurred. The Company capitalizes project costs relating to computer software developed or obtained for internal use when the activities related to the project reach the application development stage. Costs that are associated with preliminary stage activities, training, maintenance, and all other post-implementation stage activities are expensed as they are incurred. Software development costs are depreciated using the straight-line method over the estimated useful lives, which range from 3 to 10 years. Revenue Recognition The Company recognizes revenue when persuasive evidence of an arrangement exists, product has been delivered or services have been rendered, the price is fixed or determinable and collectability is reasonably assured. Revenue as reflected in the accompanying consolidated statements of operations is net of estimated sales returns and allowances. The Company's customer sales return policy generally allows customers to return products only if the products can be resold at full value or returned to suppliers for full credit. The Company records an accrual for estimated customer sales returns at the time of sale to the customer. At September 30, 2015 and 2014, the Company's accrual for estimated customer sales returns was $841.3 million and $932.6 million, respectively. The Company reports the gross dollar amount of bulk deliveries to customer warehouses in revenue and the related costs in cost of goods sold. Bulk delivery transactions are arranged by the Company at the express direction of the customer, and involve either drop shipments from the supplier directly to customers' warehouse sites or cross-dock shipments from the supplier to the Company for immediate shipment to the customers' warehouse sites. The Company is a principal to these transactions because it is the primary obligor and has the ultimate and contractual responsibility for fulfillment and acceptability of the products purchased, and bears full risk of delivery and loss for products, whether the products are drop-shipped or shipped via cross-dock. The Company also bears full credit risk associated with the creditworthiness of any bulk delivery customer. As a result, the Company records bulk deliveries to customer warehouses as gross revenues. Gross profit earned by the Company on bulk deliveries was not material in any year presented. Share-Based Compensation The Company accounts for the compensation cost of all share-based payments at fair value and reports the related expense within distribution, selling and administrative expenses to correspond with the same line item as the cash compensation paid to employees. The benefits of tax deductions in excess of recognized compensation expense are reported as a financing cash flow ($88.1 million, $46.3 million, and $41.2 million for the fiscal years ended September 30, 2015, 2014, and 2013, respectively). The fair value of performance stock units is determined by the grant date market price of the Company's Common Stock and the compensation expense associated with nonvested performance stock units is dependent on the Company's periodic assessment of the probability of the targets being achieved and its estimate of the number of shares that will ultimately be issued. Shipping and Handling Costs Shipping and handling costs include all costs to warehouse, pick, pack and deliver inventory to customers. These costs, which were $419.2 million, $348.3 million and $267.3 million for the fiscal years ended September 30, 2015, 2014, and 2013, respectively, are included in distribution, selling and administrative expenses. Supplier Reserves The Company establishes reserves against amounts due from its suppliers relating to various price and rebate incentives, including deductions or billings taken against payments otherwise due them from the Company. These reserve estimates are established based on the judgment of Company management after carefully considering the status of current outstanding claims, historical experience with the suppliers, the specific incentive programs and any other pertinent information available to the Company. The Company evaluates the amounts due from its suppliers on a continual basis and adjusts the reserve estimates when appropriate based on changes in factual circumstances. The ultimate outcome of any outstanding claim may be different than the Company's estimate. Warrants The Company accounts for the warrants issued to subsidiaries of WBA (collectively, the "Warrants") in accordance with the guidance for equity-based payments to non-employees. The various agreements and arrangements with WBA established various performance commitments that they must satisfy during the vesting periods of the Warrants, and if not fulfilled, the Company has the right to cancel the Warrants. Using a binomial lattice model approach, the fair value of the Warrants was initially measured at the date of issuance, and is being expensed over the three and four year vesting periods as an operating expense. The fair value of the Warrants are re-measured at the end of each quarterly reporting period, and an adjustment is recorded in the statement of operations to record the impact as if the newly measured fair value of the awards had been used in recognizing expense starting when the awards were originally issued and through the remeasurement date. In total, the Warrants were valued at $1,917.9 million as of September 30, 2015. The valuation of the Warrants considers the Company's Common Stock price and various assumptions, such as the volatility of the Company's Common Stock, the expected remaining life of the Warrants, the expected dividend yield, and the risk-free interest rate. As a result, future Warrant expense could fluctuate significantly (see Note 8).

Acquisition

Acquisition	12 Months Ended
	Sep. 30, 2015
Business Combinations [Abstract]
Business Combination Disclosure [Text Block]	Note 2. Acquisition On February 24, 2015, the Company acquired MWI Veterinary Supply, Inc. ("MWI") for a purchase price of $2.6 billion. MWI is a leading animal health distribution company in the United States and in the United Kingdom. MWI's annual revenues are estimated to be approximately $3.0 billion. For reportable segment presentation, MWI's operating results are included within Other. The purchase price has been allocated to the underlying assets acquired and liabilities assumed based upon their estimated fair values at the date of the acquisition. The purchase price exceeded the fair value of the net tangible and intangible assets acquired by $1.2 billion, which was allocated to goodwill. The fair value of accounts receivable, inventory, and accounts payable acquired was $346.9 million, $440.0 million and $327.1 million, respectively. The fair value of the intangible assets acquired totaled $1.5 billion and consisted of customer relationships of $1.1 billion, trade name of $344.0 million, and software technology of $11.0 million. The Company established a deferred tax liability of $570.7 million primarily in connection with the intangible assets acquired. The Company is amortizing the fair values of the acquired customer relationships and software technology over the remaining useful lives of 20 years and 8 years, respectively. The trade name has been determined to have an indefinite life. Goodwill and intangibles resulting from the acquisition are not deductible for income tax purposes.

Equity Method Investments

Equity Method Investments	12 Months Ended
	Sep. 30, 2015
Equity Method Investments and Joint Ventures Abstract
Equity Method Investments Disclosure Text Block	Note 3. Equity Method Investments In June 2014, the Company completed the acquisition of a minority ownership interest in Profarma Distribuidora de Produtos Farmacêuticos S.A. ("Profarma"), a leading pharmaceutical wholesaler in Brazil. In addition, the Company and Profarma launched a joint venture to provide enhanced specialty distribution and services to the Brazilian marketplace. The Company invested a total of $117.8 million to acquire both a minority ownership interest in Profarma of approximately 19.9% and a 50% ownership interest in the specialty joint venture. The Company accounts for its interest in both Profarma and the specialty joint venture as equity method investments, which are reported in the Other Assets line item on the consolidated balance sheet. In fiscal 2015, the Company recorded an impairment charge of $30.6 million relating to its 19.9% minority ownership interest in Profarma. The impairment charge was based on the determination by the Company that the decline in Profarma's stock price from the date on which the investment was made to September 30, 2015 was other-than-temporary. As of September 30, 2015, the carrying value of the Company's equity method investments in Brazil was $30.5 million after adjusting for changes in exchange rates and earnings.

Discontinued Operations

Discontinued Operations	12 Months Ended
	Sep. 30, 2015
Discontinued Operation Income Loss From Discontinued Operation Disclosures Abstract
Disposal Groups Including Discontinued Operations Disclosure Text Block	Note 4. Discontinued Operations In May 2013, the Company completed the divestiture of its packaging and clinical trials services business, AndersonBrecon ("AB"), and AmerisourceBergen Canada Corporation ("ABCC"). The Company has classified AB and ABCC's operating results, net of tax, as discontinued operations in the accompanying consolidated statements of operations for all periods presented. Prior to being classified within discontinued operations, AB was included in Other and ABCC was included in Pharmaceutical Distribution for segment reporting. AB and ABCC's revenue and loss before income taxes were as follows: Fiscal Year Ended September 30, (in thousands) 2015 2014 2013 Revenue $ — $ — $ Loss before income taxes $ — $ ) $ ) The loss before income taxes in the fiscal year ended September 30, 2014 includes the impact of a final purchase price working capital adjustment related to the divestiture of ABCC. The loss before income taxes in the fiscal year ended September 30, 2013 includes an ABCC goodwill impairment charge of $26.9 million and a $143.7 million loss on the sale of ABCC. The loss is net of a $114.1 million gain on the sale of AB. The gain on the sale of AB and the loss on the sale of ABCC include the reclassification of $9.3 million of cumulative foreign currency translation losses previously included within accumulated other comprehensive income. The tax gain on the sale of AB was more than offset by the tax loss on the sale of ABCC. There was no impact on income tax expense, as a valuation allowance on the excess capital tax loss was recorded. The Company sold AB for $306.5 million, net of a final purchase price working capital adjustment, and sold ABCC for $67.9 million, including a C$50.0 million note due from the buyer, with interest accruing at 3% annually, and scheduled monthly payments to be made over a seven-year term that commenced in June 2013. The Company entered into a foreign currency denominated contract to hedge the foreign currency exchange risk associated with the Canadian Note.

Income Taxes

Income Taxes	12 Months Ended
	Sep. 30, 2015
Income Taxes [Abstract]
Income Taxes [Text Block]	Note 5. Income Taxes The following illustrates domestic and foreign income from continuing operations before income taxes (in thousands): Fiscal year ended September 30, 2015 2014 2013 Domestic $ $ $ Foreign ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Total $ $ $ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ The income tax provision is as follows (in thousands): Fiscal Year Ended September 30, 2015 2014 2013 Current provision: Federal $ $ $ State and local Foreign ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Deferred provision: Federal State and local ) Foreign ) ) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Provision for income taxes $ $ $ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ A reconciliation of the statutory U.S. federal income tax rate to the effective income tax rate is as follows: Fiscal Year Ended September 30, 2015 2014 2013 Statutory U.S. federal income tax rate State and local income tax rate, net of federal tax benefit Foreign Warrants Valuation allowance — Other ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Effective income tax rate ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ In March 2013, the Company issued Warrants in connection with various agreements and arrangements with WBA. See Note 8 for further details. As of the date of issuance, the Warrants were valued at $242.4 million, which approximates the amount deductible for tax purposes. The fair value of the Warrants as of September 30, 2015 was $1,917.9 million. The excess of the fair value as of September 30, 2015 over the initial value of $242.4 million is not tax deductible (see Note 18 — Subsequent Events ). As a result, the Company's effective income tax rate in the fiscal years ended September 30, 2015 and 2014 is higher than its historic rate. This increase in the income tax rate is reflected in Warrants in the above effective income tax rate reconciliation. Deferred income taxes reflect the future tax consequences of differences between the tax bases of assets and liabilities and their financial reporting amounts. Significant components of the Company's deferred tax liabilities (assets) are as follows (in thousands): September 30, 2015 2014 Merchandise inventories $ $ Property and equipment Goodwill and other intangible assets Other ​ ​ ​ ​ ​ ​ ​ ​ Gross deferred tax liabilities ​ ​ ​ ​ ​ ​ ​ ​ Net operating loss and tax credit carryforwards ) ) Capital loss carryforwards ) ) Allowance for doubtful accounts ) ) Accrued expenses ) ) Employee and retiree benefits ) ) Stock options ) ) Warrants ) ) Other ) ) ​ ​ ​ ​ ​ ​ ​ ​ Gross deferred tax assets ) ) Valuation allowance for deferred tax assets ​ ​ ​ ​ ​ ​ ​ ​ Deferred tax assets, net of valuation allowance ) ) ​ ​ ​ ​ ​ ​ ​ ​ Net deferred tax liabilities $ $ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ The following tax carryforward information is presented as of September 30, 2015. The Company had $6.2 million of potential tax benefits from federal net operating loss carryforwards expiring in 3 to 16 years, $75.9 million of potential tax benefits from state net operating loss carryforwards expiring in 1 to 20 years and $15.4 million of potential tax benefits from foreign net operating loss carryforwards, which have varying expiration dates. Included in the state net operating loss carryforwards is $13.2 million of potential tax benefits that if realized would be an increase to additional paid-in-capital. The Company had $65.8 million of potential tax benefits from capital loss carryforwards expiring in 1 to 5 years. The Company had $5.8 million of foreign tax credit carryforwards expiring in 3 to 9 years. The Company had $2.2 million of state tax credit carryforwards and $2.1 million in alternative minimum tax credit carryforwards. In fiscal 2015, the Company increased the valuation allowance on deferred tax assets by $26.7 million primarily due to the addition of certain state net operating loss carryforwards. In fiscal 2014, the Company decreased the valuation allowance on deferred tax assets by $222.2 million primarily due to the expiration of capital loss carryforwards. In fiscal 2015, 2014, and 2013, tax benefits of $88.1 million, $46.3 million, and $41.2 million, respectively, related to the exercise of employee stock options and lapse of restricted shares, were recorded as additional paid-in capital. Income tax payments, net of refunds, were $299.6 million, $197.0 million and $313.7 million in the fiscal years ended September 30, 2015, 2014 and 2013, respectively. The Company and its subsidiaries file income tax returns in the U.S. federal jurisdiction, and various states and foreign jurisdictions. With few exceptions, the Company is no longer subject to U.S. federal, state and local, or foreign income tax examinations by tax authorities for years before 2011. As of September 30, 2015 and 2014, the Company had unrecognized tax benefits, defined as the aggregate tax effect of differences between tax return positions and the benefits recognized in the Company's financial statements, of $52.8 million and $50.6 million, respectively, ($37.2 million and $35.8 million, net of federal benefit, respectively). If recognized, these tax benefits would reduce income tax expense and the effective tax rate. As of September 30, 2015 and 2014, included in these amounts are $8.1 million and $7.7 million of interest and penalties, respectively, which the Company records in income tax expense. A reconciliation of the beginning and ending amount of unrecognized tax benefits, excluding interest and penalties, in fiscal 2015, 2014, and 2013 is as follows (in thousands): Balance at September 30, 2012 $ Additions of tax positions of the current year Additions of tax positions of the prior years Additions of tax positions due to acquisitions Settlements with taxing authorities ) Expiration of statutes of limitations ) ​ ​ ​ ​ ​ Balance at September 30, 2013 Additions of tax positions of the current year Additions of tax positions of the prior years Reductions of tax positions of the prior years ) Settlements with taxing authorities ) Expiration of statutes of limitations ) ​ ​ ​ ​ ​ Balance at September 30, 2014 Additions of tax positions of the current year Reductions of tax positions of the prior years ) Settlements with taxing authorities ) Expiration of statutes of limitations ) ​ ​ ​ ​ ​ Balance at September 30, 2015 $ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ During the next 12 months, it is reasonably possible that state tax audit resolutions and the expiration of statutes of limitations could result in a reduction of unrecognized tax benefits by approximately $9.5 million. Cumulative undistributed earnings of international subsidiaries were $412.7 million at September 30, 2015. No deferred Federal income taxes were provided for the undistributed earnings as they are permanently reinvested in the Company's international operations. It is not practicable to estimate the amount of U.S. tax that would result upon the eventual repatriation of such earnings.

Goodwill and Other Intangible A

Goodwill and Other Intangible Assets	12 Months Ended
	Sep. 30, 2015
Goodwill and Other Intangible Assets [Abstract]
Goodwill and Other Intangible Assets [Text Block]	Note 6. Goodwill and Other Intangible Assets Following is a summary of the changes in the carrying value of goodwill for the fiscal years ended September 30, 2015 and 2014 (in thousands): Pharmaceutical Distribution Other Total Goodwill at September 30, 2013 $ $ $ Goodwill recognized in connection with acquisitions — Foreign currency translation — ) ) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Goodwill at September 30, 2014 Goodwill recognized in connection with acquisitions Goodwill disposed in connection with divestitures ) ) ) Foreign currency translation — ) ) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Goodwill at September 30, 2015 $ $ $ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Following is a summary of other intangible assets (in thousands): September 30, 2015 September 30, 2014 Gross Carrying Amount Accumulated Amortization Net Carrying Amount Gross Carrying Amount Accumulated Amortization Net Carrying Amount Indefinite-lived intangibles — trade names $ $ — $ $ $ — $ Finite-lived intangibles: Customer relationships ) ) Other ) ) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Total other intangible assets $ $ ) $ $ $ ) $ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Amortization expense for other intangible assets was $56.5 million, $26.0 million, and $27.1 million in the fiscal years ended September 30, 2015, 2014, and 2013, respectively. Amortization expense for other intangible assets is estimated to be $82.1 million in fiscal 2016, $79.0 million in fiscal 2017, $76.6 million in fiscal 2018, $74.9 million in fiscal 2019, $72.6 million in 2020 and $923.0 million thereafter.

Debt

Debt	12 Months Ended
	Sep. 30, 2015
Debt [Abstract]
Debt [Text Block]	Note 7. Debt Debt consisted of the following: September 30, 2015 2014 (Dollars in thousands) Multi-currency revolving credit facility due 2019 $ — $ — Receivables securitization facility due 2017 — — Revolving credit note — — Overdraft facility — — Term loan — $600,000, 1.15% senior notes due 2017 $400,000, 4.875% senior notes due 2019 $500,000, 3.50% senior notes due 2021 $500,000, 3.40% senior notes due 2024 $500,000, 3.25% senior notes due 2025 — $500,000, 4.25% senior notes due 2045 — ​ ​ ​ ​ ​ ​ ​ ​ Total debt $ $ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Multi-Currency Revolving Credit Facility The Company has a $1.4 billion multi-currency senior unsecured credit facility, which was scheduled to expire in August 2019 (the "Multi-Currency Revolving Credit Facility"), with a syndicate of lenders. In November 2015, the Company entered into an amendment with the syndicate of lenders to extend the maturity date to November 2020. Interest on borrowings under the Multi-Currency Revolving Credit Facility accrues at specified rates based on the Company's debt rating and ranges from 69 basis points to 110 basis points over LIBOR/EURIBOR/Bankers Acceptance Stamping Fee, as applicable (90 basis points over LIBOR/EURIBOR/Bankers Acceptance Stamping Fee at September 30, 2015). Additionally, interest on borrowings denominated in Canadian dollars may accrue at the greater of the Canadian prime rate or the CDOR rate. The Company pays facility fees to maintain the availability under the Multi-Currency Revolving Credit Facility at specified rates based on its debt rating, ranging from 6 basis points to 15 basis points, annually, of the total commitment (10 basis points at September 30, 2015). The Company may choose to repay or reduce its commitments under the Multi-Currency Revolving Credit Facility at any time. The Multi-Currency Revolving Credit Facility contains covenants, including compliance with a financial leverage ratio test, as well as others that impose limitations on, among other things, indebtedness of excluded subsidiaries and asset sales, with which the Company was compliant as of September 30, 2015. Receivables Securitization Facility The Company has a $950 million receivables securitization facility (the "Receivables Securitization Facility"), which was scheduled to expire in December 2017. In November 2015, the Company extended the maturity date to November 2018. The Company has available to it an accordion feature whereby the commitment on the Receivables Securitization Facility may be increased by up to $250 million, subject to lender approval, for seasonal needs during the December and March quarters. Interest rates are based on prevailing market rates for short-term commercial paper or LIBOR plus a program fee. The Company pays a customary unused fee at prevailing market rates, annually, to maintain the availability under the Receivables Securitization Facility. In connection with the Receivables Securitization Facility, AmerisourceBergen Drug Corporation sells on a revolving basis certain accounts receivable to Amerisource Receivables Financial Corporation, a wholly owned special purpose entity, which in turn sells a percentage ownership interest in the receivables to financial institutions and commercial paper conduits sponsored by financial institutions. AmerisourceBergen Drug Corporation is the servicer of the accounts receivable under the Receivables Securitization Facility. After the maximum limit of receivables sold has been reached and as sold receivables are collected, additional receivables may be sold up to the maximum amount available under the facility. The facility is a financing vehicle utilized by the Company because it generally offers an attractive interest rate relative to other financing sources. The Company securitizes its trade accounts, which are generally non-interest bearing, in transactions that are accounted for as borrowings. The Receivables Securitization Facility contains similar covenants to the Multi-Currency Revolving Credit Facility, with which the Company was compliant as of September 30, 2015. Commercial Paper Program The Company has a commercial paper program whereby it may from time to time issue short-term promissory notes in an aggregate amount of up to $1.4 billion at any one time. Amounts available under the program may be borrowed, repaid, and re-borrowed from time to time. The maturities on the notes will vary, but may not exceed 365 days from the date of issuance. The notes will bear interest rates, if interest bearing, or will be sold at a discount from their face amounts. The commercial paper program does not increase the Company's borrowing capacity as it is fully backed by the Company's Multi-Currency Revolving Credit Facility. There were no borrowings outstanding under the commercial paper program at September 30, 2015. Revolving Credit Note and Overdraft Facility The Company has an uncommitted, unsecured line of credit available to it pursuant to a revolving credit note (the "Revolving Credit Note"). The Revolving Credit Note provides the Company with the ability to request short-term, unsecured revolving credit loans from time to time in a principal amount not to exceed $75 million. The Revolving Credit Note may be decreased or terminated by the bank or the Company at any time without prior notice. The Company also has an uncommitted U.K. overdraft facility ("Overdraft Facility"), which allows it to borrow up to £20 million to fund short term normal trading cycle fluctuations related to its MWI business. The Overdraft Facility expires in November 2016. Term Loan In February 2015, the Company entered into a $1.0 billion term loan credit agreement (the "Term Loan"), which matures in 2020. The Term Loan is subject to quarterly principal payments equal to (1) 1.25% of the aggregate principal amount of the Term Loan beginning with the first quarterly principal payment in June 2015 to and including March 2018, and (2) thereafter, 2.50% of the aggregate principal amount of the Term Loan, with the remaining balance of the Term Loan due upon maturity. In fiscal 2015, the Company elected to make early principal payments totaling $500 million on the Term Loan, $25.0 million of which was scheduled to be paid in fiscal 2015. The payments were applied in direct order to scheduled principal payments, and as a result, the Company's next required principal payment is due upon maturity. The Term Loan will bear interest at a rate equal either to a base rate plus a margin or a LIBOR rate plus a margin. The margin will be based on the public debt ratings of the Company and ranges from 75 basis points to 125 basis points over a LIBOR rate (100 basis points at September 30, 2015) and 0 to 25 basis points over a base rate. The Term Loan contains similar covenants to the Multi-Currency Revolving Credit Facility, with which the Company was compliant as of September 30, 2015. Senior Notes In February 2015, the Company issued $500 million of 3.25% senior notes due March 1, 2025 (the "2025 Notes") and $500 million of 4.25% senior notes due March 1, 2045 (the "2045 Notes"). The 2025 Notes were sold at 99.47% of the principal amount and have an effective yield of 3.31%. The 2045 Notes were sold at 99.81% of the principal amount and have an effective yield of 4.26%. The interest on the 2025 and 2045 Notes is payable semi-annually in arrears, commencing on September 1, 2015. The 2025 and 2045 Notes rank pari passu to the Multi-Currency Revolving Credit Facility, the Revolving Credit Note, the Overdraft Facility, the $600 million 1.15% senior notes due in 2017, the $400 million 4.875% senior notes due in 2019, the $500 million 3.50% senior notes due in 2021, and the $500 million 3.40% senior notes due in 2024. The Company used the proceeds from the Term Loan, the 2025 Notes and the 2045 Notes to finance a portion of the $2.6 billion purchase price of MWI. In May 2014, the Company issued $600 million of 1.15% senior notes due May 15, 2017 (the "2017 Notes") and $500 million of 3.40% senior notes due May 15, 2024 (the "2024 Notes"). The 2017 Notes were sold at 99.892% of the principal amount and have an effective yield of 1.187%. The 2024 Notes were sold at 99.715% of the principal amount and have an effective yield of 3.434%. Interest on the 2017 Notes and 2024 Notes is payable semiannually in arrears. The Company used a portion of the net proceeds from the 2017 Notes and the 2024 Notes to finance the early retirement of the $500 million, 5.875% senior notes due 2015 (the "2015 Notes"), including the payment of $31.5 million of premiums and other costs. The Company used the remaining amount for general corporate purposes, including the repurchases of shares of its common stock under its special share repurchase program. The Company has $400 million of 4.875% senior notes due November 15, 2019 (the "2019 Notes") and $500 million of 3.50% senior notes due November 15, 2021 (the "2021 Notes"). The 2019 Notes, and 2021 Notes were sold at 99.2% and 99.858% of the principal amount, respectively, and have effective interest yields of 4.98% and 3.52% respectively. Interest on the 2019 and 2021 Notes is payable semiannually in arrears. The 2017 Notes, 2019 Notes, 2021 Notes, 2024 Notes, 2025 Notes, and 2045 Notes are collectively referred to as the "Notes." Costs incurred in connection with the issuance of the Notes were deferred and are being amortized over the terms of the Notes. The indentures governing the Notes contain restrictions and covenants which include limitations on additional indebtedness; distributions to stockholders; the repurchase of stock and the making of other restricted payments; issuance of preferred stock; creation of certain liens; transactions with subsidiaries and other affiliates; and certain corporate acts such as mergers, consolidations, and the sale of substantially all assets. An additional covenant requires compliance with a financial leverage ratio test, with which the Company was compliant as of September 30, 2015. Other Information Scheduled future principal payments of long-term debt are $600 million in fiscal 2017, $900 million in fiscal 2019, and $2.0 billion in fiscal 2021 and thereafter. Interest paid on the above indebtedness during the fiscal years ended September 30, 2015, 2014, and 2013 was $91.5 million, $62.9 million, and $68.5 million, respectively. Total amortization of financing fees and the accretion of original issue discounts, which are recorded as components of interest expense, were $5.2 million, $3.9 million, and $4.2 million, for the fiscal years ended September 30, 2015, 2014, and 2013, respectively.

Stockholders' Equity and Earnin

Stockholders' Equity and Earnings per Share	12 Months Ended
	Sep. 30, 2015
Stockholders' Equity and Earnings per Share [Abstract]
Stockholders' Equity and Earnings per Share [Text Block]	Note 8. Stockholders' Equity and Earnings per Share The authorized capital stock of the Company consists of 600,000,000 shares of common stock, par value $0.01 per share (the "Common Stock"), and 10,000,000 shares of preferred stock, par value $0.01 per share (the "Preferred Stock"). The board of directors is authorized to provide for the issuance of shares of Preferred Stock in one or more series with various designations, preferences and relative, participating, optional or other special rights and qualifications, limitations or restrictions. Except as required by law, or as otherwise provided by the board of directors of the Company, the holders of Preferred Stock will have no voting rights and will not be entitled to notice of meetings of stockholders. Holders of Preferred Stock will be entitled to receive, when declared by the board of directors, out of legally available funds, dividends at the rates fixed by the board of directors for the respective series of Preferred Stock, and no more, before any dividends will be declared and paid, or set apart for payment, on Common Stock with respect to the same dividend period. No shares of Preferred Stock have been issued as of September 30, 2015. The holders of the Company's Common Stock are entitled to one vote per share and have the exclusive right to vote for the board of directors and for all other purposes as provided by law. Subject to the rights of holders of the Company's Preferred Stock, holders of Common Stock are entitled to receive ratably on a per share basis such dividends and other distributions in cash, stock or property of the Company as may be declared by the board of directors from time to time out of the legally available assets or funds of the Company. The following table illustrates the components of accumulated other comprehensive loss, net of income taxes, as of September 30, 2015 and 2014 (in thousands): September 30, 2015 2014 Pension and postretirement adjustments (See Note 9) $ ) $ ) Foreign currency translation ) ) Other ) ) ​ ​ ​ ​ ​ ​ ​ ​ Total accumulated other comprehensive loss $ ) $ ) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ In May 2012, the Company's board of directors authorized a program allowing the Company to purchase up to $750 million of its outstanding shares of Common Stock, subject to market conditions. In August 2012, the Company entered into an Accelerated Share Repurchase ("ASR") transaction with a financial institution and paid $650 million for the initial delivery of 16.8 million shares. The initial payment of $650 million funded stock purchases of $647.2 million, $2.0 million of previously declared dividends that were scheduled to be paid in September 2012, and $0.8 million in other fees. The number of shares ultimately purchased was based on the volume-weighted average price of the Company's Common Stock during the term of the ASR. The ASR transaction was settled in October 2012, at which time the Company received 0.1 million incremental shares. In addition to the ASR transaction, during the fiscal year ended September 30, 2012, the Company purchased 0.2 million shares of its Common Stock for a total of $5.9 million. During the fiscal year ended September 30, 2013, the Company purchased 0.6 million shares of its Common Stock for a total of $25.7 million under this program. This program was closed during the fiscal year ended September 2013 as a result of the November 2012 ASR transaction (see below). In November 2012, the Company's board of directors authorized a program allowing the Company to purchase up to $750 million of its outstanding shares of Common Stock, subject to market conditions. Subsequently, in November 2012, the Company entered into an ASR transaction with a financial institution and paid $250 million for a delivery of 6.2 million shares. The initial payment of $250 million funded stock purchases of $248.5 million, $1.3 million of previously declared dividends that were scheduled to be paid in December 2012, and $0.2 million in other fees. The amount ultimately paid was based on the volume-weighted average price of the Company's Common Stock during the term of the ASR. The ASR transaction was settled in December 2012, at which time the Company paid the financial institution a cash settlement of $10.3 million. The Company applied 1.7 million shares for $71.2 million to the May 2012 share repurchase program, which completed its authorization under that program. The Company applied the remaining 4.5 million shares from the November 2012 ASR for $187.6 million to the November 2012 share repurchase program. In addition to the ASR transaction, during the fiscal year ended September 30, 2013, the Company purchased 3.6 million shares of its Common Stock for a total of $199.4 million. During the fiscal year ended September 30, 2014, the Company purchased 5.5 million shares of its Common Stock for a total of $363.0 million to complete its authorization under this program. In August 2013, the Company's board of directors authorized the Company to purchase up to $750 million of its outstanding shares of Common Stock, subject to market conditions. During the fiscal year ended September 30, 2014, the Company purchased 2.4 million shares of its Common Stock for a total of $174.7 million under this program, which included $18.0 million fiscal 2014 purchases that cash settled in October 2014. During the fiscal year ended September 30, 2015, the Company purchased 3.3 million shares of its Common Stock for a total of $300.8 million under this program. The Company had $274.5 million of availability remaining under this share repurchase program as of September 30, 2015. In March 2013, the Company and WBA entered into various agreements and arrangements pursuant to which subsidiaries of WBA were granted the right to purchase a minority equity position in the Company, beginning with the right, but not the obligation, to purchase up to 19,859,795 shares of the Company's Common Stock (approximately 7% of the Company's Common Stock, on a fully diluted basis as of the date of issuance, assuming the exercise in full of the Warrants, as defined below) in open market transactions. In connection with these arrangements, Walgreens Pharmacy Strategies, LLC, a wholly owned subsidiary of WBA, was issued (a) a warrant to purchase up to 11,348,456 shares of the Company's Common Stock at an exercise price of $51.50 per share exercisable during a six-month period beginning in March 2016, and (b) a warrant to purchase up to 11,348,456 shares of the Company's Common Stock at an exercise price of $52.50 per share exercisable during a six-month period beginning in March 2017 and Alliance Boots Luxembourg S.à.r.l., a wholly owned subsidiary of WBA, was issued (a) a warrant to purchase up to 11,348,456 shares of the Company's common Stock at an exercise price of $51.50 per share exercisable during a six-month period beginning in March 2016, and (b) a warrant to purchase up to 11,348,456 shares of the Company's Common Stock at an exercise price of $52.50 per share exercisable during a six-month period beginning March 2017 (collectively, the "Warrants"). The Company valued these Warrants as of March 18, 2013 (date of issuance) and revised the valuation each subsequent quarter. As of September 30, 2015, the Warrants with an exercise price of $51.50 were valued at $43.03 per share and the Warrants with an exercise price of $52.50 were valued at $41.47 per share. In total, the Warrants were valued at $1,917.9 million as of September 30, 2015. The Company has taken steps to mitigate the potentially dilutive effect that exercise of the Warrants could have by hedging a portion of its future obligation to deliver Common Stock with a financial institution and repurchasing additional shares of its Common Stock for the Company's own account over time. In June 2013, the Company commenced its hedging strategy by entering into a contract with a financial institution pursuant to which it has executed a series of issuer capped call transactions ("Capped Calls"). The Capped Calls give the Company the right to buy shares of its Common Stock subject to the Warrants at specified prices at maturity, should the Warrants be exercised in 2016 and 2017 and were initially intended to cover approximately 60% of the shares subject to the Warrants at the time the Company entered into the transactions. If the Warrants are exercised, the Company will use a majority of the proceeds to repurchase its shares under the Capped Calls. The Capped Calls are subject to a "cap" price. If the Company's share price exceeds the "cap" price in the Capped Calls at the time the Warrants are exercised, the number of shares that will be delivered to the Company under the Capped Calls will be reduced, and accordingly, will cover less than 60% of the shares of Common Stock subject to the Warrants. This hedge transaction was completed in January 2014, and included the purchase of Capped Calls on a total of 27.2 million shares of the Company's common stock for a total premium of $368.7 million. Based upon the Company's recent share price, the number of shares of common stock the Company expects to receive under the Capped Calls at maturity has been reduced. Therefore, the Company amended certain of the Capped Calls to increase their "cap" price to continue to address the potentially dilutive effect of the Warrants. The Company paid a premium of $100.0 million in January 2015 to increase the cap price on certain of the Capped Calls subject to the warrants that become exercisable in 2016. The Capped Calls permit the Company to acquire shares of its common stock at strike prices of $51.50 and $52.50 and have expiration dates ranging from February 2016 through October 2017. The Capped Calls permit net share settlement, which is limited by caps on the market price of the Company's common stock. The Company has accounted for the Capped Calls as equity contracts and therefore, the above premiums were recorded as a reduction to paid-in capital. In May 2014, the Company's board of directors authorized a special program allowing the Company to purchase up to $650 million of its outstanding shares of Common Stock, subject to market conditions, as an opportunity to further mitigate the potentially dilutive effect of the Warrants and supplements the Company's previously executed warrant hedging strategy. During the fiscal year ended September 30, 2014, the Company purchased 3.4 million shares of its Common Stock for a total of $252.0 million under this program, which included $18.0 million of purchases that cash settled in October 2014. During the fiscal year ended September 30, 2015, the Company purchased 4.3 million shares (1.6 million under the Call Options for a total of $151.2 million, as defined below) of its Common Stock for a total of $398.0 million under this program, which excluded $18.0 million of purchases that cash settled in October 2014, to complete its authorization under this program. In March 2015, the Company supplemented its hedging strategy by entering into a contract with a financial institution pursuant to which it has executed a series of issuer call options ("Call Options"). The Call Options give the Company the right to buy shares of its common stock subject to the Warrants at specified prices between April 2015 and October 2015. In total, the Company purchased Call Options on six million shares of its common stock for a total premium of $80.0 million. The Company has accounted for the Call Options as equity contracts and therefore, the above premiums were recorded as a reduction to paid-in capital. In April 2015, the Company's board of directors authorized a new special share repurchase program allowing it to repurchase up to $1.0 billion in shares of its common stock, subject to market conditions, to further mitigate the potentially dilutive effect of the Warrants as part of its warrant hedging strategy. During the fiscal year ended September 30, 2015, the Company purchased 10.0 million shares (2.9 million under the Call Options for a total of $276.3 million) of its common stock for a total of $1.0 billion under this program to complete its authorization under this program. In September 2015, the Company's board of directors authorized a new special share repurchase program allowing it to repurchase up to $2.4 billion in shares of its common stock, subject to market conditions. During the fiscal year ended September 30, 2015, the Company purchased 1.2 million shares of its common stock for a total of $124.1 million under this program. The Company had $2,275.9 million of availability remaining under this special share repurchase program as of September 30, 2015. Availability under the new special share repurchase program is reduced by share repurchases, if any, of its common stock on the open market under the special program, as well as share repurchases related to the Company's exercise of Call Options and/or Capped Calls. Based on the closing stock price of the Company's common stock on September 30, 2015, the Capped Calls associated with the warrants exercisable in 2016 would have covered approximately 56% of the shares subject to the warrants and the Capped Calls associated with the warrants exercisable in 2017 would have covered 50% of the shares subject to the warrants. Adding the shares repurchased through September 30, 2015 under the special share repurchase programs, the Company would have covered 100% of the warrants exercisable in 2016 and approximately 89% of the warrants exercisable in 2017. Basic earnings per share is computed on the basis of the weighted average number of shares of common stock outstanding during the periods presented. Diluted earnings per share is computed on the basis of the weighted average number of shares of common stock outstanding during the periods presented plus the dilutive effect of stock options, restricted stock, restricted stock units, and the Warrants. The following table (in thousands) illustrates the components of diluted weighted average shares outstanding: September 30, 2015 2014 2013 Weighted average common shares outstanding — basic Effect of dilutive securities — stock options, restricted stock, and restricted stock units — Dilutive effect of Warrants — — ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Weighted average common shares outstanding — diluted ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ The potentially dilutive employee stock options, restricted stock, restricted stock units, and Warrants that were antidilutive for fiscal 2015 and 2014 were 18.6 million and 2.0 million, respectively. There were no potentially dilutive stock options, restricted stock, or restricted stock units that were antidilutive for fiscal 2013. All Warrants were antidilutive for fiscal 2013.

Pension and Other Benefit Plans

Pension and Other Benefit Plans	12 Months Ended
	Sep. 30, 2015
Compensation and Retirement Disclosure [Abstract]
Pension And Other Postretirement Benefits Disclosure Text Block	Note 9. Pension and Other Benefit Plans The Company sponsors various retirement benefit plans, including defined benefit pension plans, defined contribution plans, postretirement medical plans and a deferred compensation plan covering eligible employees. Expenses relating to these plans were $26.4 million, $27.9 million, and $22.1 million in fiscal 2015, 2014, and 2013, respectively. The Company recognizes the funded status (the difference between the fair value of plan assets and the projected benefit obligations) of its defined benefit pension plans and postretirement benefit plans in its balance sheet, with a corresponding adjustment to accumulated other comprehensive loss, net of income taxes. Included in accumulated other comprehensive loss at September 30, 2015 are net actuarial losses of $59.1 million ($36.8 million, net of income taxes). The Compensation and Succession Planning Committee ("Compensation Committee") of the Company's board of directors has delegated the administration of the pension and benefit plans to the Company's Benefits Committee, an internal committee, composed of senior finance, human resources and legal executives. The Benefits Committee is responsible for oversight of the investment management of the assets of the Company's pension plans and the investment options under the Company's savings plans, as well as the performance of the investment advisers and plan administrators. The Benefits Committee has adopted an investment policy for the Company's pension plans, which includes guidelines regarding, among other things, the selection of acceptable asset classes, allowable ranges of holdings, rebalancing of assets, the definition of acceptable securities within each class, and investment performance expectations. Defined Benefit Plans The Company provides a benefit for certain employees under two different noncontributory defined benefit pension plans consisting of a salaried plan and a supplemental executive retirement plan. Both plans are closed to new participants and benefits that can be earned by active participants in the plans are limited. For each employee, the benefits are based on years of service and average compensation. Pension costs, which are computed using the projected unit credit cost method, are funded to at least the minimum level required by government regulations. The Company approved the termination, effective August 1, 2014, of the salaried defined benefit pension plan, under which approximately 3,200 participants, including 500 active employees, have accrued benefits. In fiscal 2015, the Company obtained regulatory approval from the Internal Revenue Service to settle the plan. The Company did not recognize a gain or loss related to the settlement of the terminated plan in the fiscal year ended September 30, 2015 as the distribution of plan assets pursuant to the termination is not expected to occur until the first quarter of fiscal 2016. Plan participants will receive vested benefits from the plan assets by electing either a lump-sum distribution or an annuity contract with a qualifying third-party provider. The purchase of the annuities will result in a one-time expense, which is primarily attributable to pension settlement accounting rules that require accelerated recognition of actuarial losses that are included in accumulated other comprehensive income. The expense is estimated to be $65 million, but is subject to change based on the actual lump sum and annuity purchase rates at the date of distribution. The Company has an unfunded supplemental executive retirement plan for certain former officers and key employees. This plan is closed to new participants and benefits that can be earned by active participants are limited. This plan is a "target" benefit plan, with the annual lifetime benefit based upon a percentage of salary during the five final years of pay at age 62, offset by several other sources of income including benefits payable under a prior supplemental retirement plan. As of September 30, 2015, the Company's pension plans had a projected benefit obligation and an accumulated benefit obligation of $159.5 million and plan assets of $168.9 million. As of September 30, 2014, the Company's pension plans had a projected benefit obligation of $161.7 million and plan assets of $175.4 million. The discount rate used in computing the benefit obligation was 4.12% and 4.08% for fiscal years ended September 30, 2015 and 2014, respectively. As a result of the planned termination of the salaried defined benefit pension plan, the target asset allocation was adjusted to only include commingled fixed-income securities and cash. The commingled fixed-income securities are diversified in terms of domestic and international securities and large cap and small cap companies. The actual and target asset allocations expressed as a percentage of the plan's assets were 64% and 99% debt securities and 36% and 1% cash and cash equivalents at September 30, 2015 and 2014, respectively. The fair value hierarchy has three levels based on the reliability of the inputs 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 determined based on unadjusted quoted prices in active markets for identical assets. Level 2 refers to fair values estimated using significant unobservable inputs and Level 3 includes fair values estimated using significant non-observable inputs. The Company's salaried defined benefit pension plan assets at September 30, 2015 were comprised of $60.5 million invested in money market funds and $108.4 million invested in commingled fixed-income funds, which have daily net asset values derived from the underlying securities, and were classified as Level 1 and Level 2 in the fair value hierarchy, respectively. The Company's pension plan assets at September 30, 2014 were comprised of $1.7 million invested in money market funds and $173.7 million invested in commingled fixed-income funds and were classified as Level 1 and Level 2 in the fair value hierarchy, respectively. The Company made no contributions to its salaried defined benefit pension plan in fiscal 2015, 2014 or 2013. Defined Contribution Plans The Company sponsors the AmerisourceBergen Employee Investment Plan, which is a defined contribution 401(k) plan covering salaried and certain hourly employees. Eligible participants may contribute to the plan from 1% to 25% of their regular compensation before taxes. The Company contributes $1.00 for each $1.00 invested by the participant up to the first 3% of the participant's salary and $0.50 for each additional $1.00 invested by the participant of up to an additional 2% of salary. An additional discretionary contribution, in an amount not to exceed the limits established by the Internal Revenue Code, may also be made depending upon the Company's performance. A discretionary contribution was made for the fiscal year ended September 30, 2014. There were no discretionary contributions made for the fiscal year ended September 30, 2015 or 2013. All contributions are invested at the direction of the employee in one or more funds. All contributions vest immediately except for the discretionary contributions made by the Company that vest in full after five years of credited service. The Company also sponsors the AmerisourceBergen Corporation Benefit Restoration Plan. This unfunded plan provides benefits for selected key management, including all of the Company's executive officers. This plan will provide eligible participants with an annual amount equal to 4% of the participant's base salary and bonus incentive to the extent that his or her compensation exceeds the annual compensation limit established by Section 401(a) (17) of the Internal Revenue Code. Costs of the defined contribution plans charged to expense for the fiscal years ended September 30, 2015, 2014, and 2013 were $23.5 million, $22.5 million, and $17.4 million, respectively. Deferred Compensation Plan The Company sponsors the AmerisourceBergen Corporation 2001 Deferred Compensation Plan. This unfunded plan, under which 2.96 million shares of Common Stock are authorized for issuance, allows eligible officers, directors and key management employees to defer a portion of their annual compensation. The amount deferred may be allocated by the employee to cash, mutual funds or stock credits. Stock credits, including dividend equivalents, are equal to the full and fractional number of shares of Common Stock that could be purchased with the participant's compensation allocated to stock credits based on the average of closing prices of Common Stock during each month, plus, at the discretion of the board of directors, up to one-half of a share of Common Stock for each full share credited. Stock credit distributions are made in shares of Common Stock. No shares of Common Stock have been issued under the deferred compensation plan through September 30, 2015. The Company's liability relating to its deferred compensation plan as of September 30, 2015 and 2014 was $18.0 million and $16.2 million, respectively.

Share-Based Compensation

Share-Based Compensation	12 Months Ended
	Sep. 30, 2015
Share-based Compensation Abstract
Disclosure of Compensation Related Costs, Share-based Payments Text Block	Note 10. Share-Based Compensation Stock Options The Company's employee stock option plans provide for the granting of incentive and nonqualified stock options to acquire shares of Common Stock to employees at a price not less than the fair market value of the Common Stock on the date the option is granted. Option terms and vesting periods are determined at the date of grant by the Compensation Committee of the board of directors. Employee options generally vest ratably, in equal amounts, over a four-year service period and expire in seven years (ten years for all grants issued prior to February 2008). The Company's non-employee director stock option plans provide for the granting of nonqualified stock options to acquire shares of Common Stock to non-employee directors at the fair market value of the Common Stock on the date of the grant. Non-employee director options vest ratably, in equal amounts, over a three-year service period and expire in ten years. At September 30, 2015, employee and non-employee director stock options for an additional 24.8 million shares may be granted under the AmerisourceBergen Corporation Omnibus Incentive Plan (the "Plan"). The estimated fair values of options granted are expensed as compensation on a straight-line basis over the requisite service periods of the awards and are net of estimated forfeitures. The Company estimates the fair values of option grants using a binomial option pricing model. Expected volatilities are based on the historical volatility of the Company's Common Stock and other factors, such as implied market volatility. The Company uses historical exercise data, taking into consideration the optionees' ages at grant date, to estimate the terms for which the options are expected to be outstanding. The Company anticipates that the terms of options granted in the future will be similar to those granted in the past. The risk-free rates during the terms of such options are based on the U.S. Treasury yield curve in effect at the time of grant. The weighted average fair values of the options granted during the fiscal years ended September 30, 2015, 2014, and 2013 were $14.91, $11.22, and $6.54, respectively. The following weighted average assumptions were used to estimate the fair values of options granted: Fiscal Year Ended September 30, 2015 2014 2013 Risk-free interest rate Expected dividend yield Volatility of common stock Expected life of the options 3.73 years 3.69 years 3.69 years Changes to the above valuation assumptions could have a significant impact on share-based compensation expense. During the fiscal years ended September 30, 2015, 2014, and 2013, the Company recorded stock option expense of $30.2 million, $21.5 million, and $20.2 million, respectively. A summary of the Company's stock option activity and related information for its option plans for the fiscal year ended September 30, 2015 is presented below: Options Weighted Average Exercise Price Weighted Average Remaining Contractual Term Aggregate Intrinsic Value (000s) (000s) Outstanding at September 30, 2014 $ 4 years Granted $ Exercised ) $ Forfeited ) $ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Outstanding at September 30, 2015 $ 4 years $ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Exercisable at September 30, 2015 $ 3 years $ Expected to vest after September 30, 2015 $ 5 years $ The intrinsic value of stock option exercises during fiscal 2015, 2014, and 2013 was $240.2 million, $132.4 million, and $131.8 million, respectively. A summary of the status of the Company's nonvested options as of September 30, 2015 and changes during the fiscal year ended September 30, 2015 is presented below: Options Weighted Average Grant Date Fair Value (000s) Nonvested at September 30, 2014 $ Granted $ Vested ) $ Forfeited ) $ ​ ​ ​ ​ ​ ​ ​ ​ Nonvested at September 30, 2015 $ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ During the fiscal years ended September 30, 2015, 2014, and 2013, the total fair values of options vested were $20.7 million, $19.1 million, and $17.4 million, respectively. Expected future compensation expense relating to the 6.4 million nonvested options outstanding as of September 30, 2015 is $41.5 million, which will be recognized over a weighted average period of 2.1 years. Restricted Stock and Restricted Stock Units Restricted shares vest in full after three years. The estimated fair value of restricted shares under the Company's restricted stock plans is determined by the product of the number of shares granted and the grant date market price of the Company's Common Stock. The estimated fair value of restricted shares is expensed on a straight-line basis over the requisite service period of three years. During the fiscal years ended September 30, 2015, 2014, and 2013, the Company recorded restricted stock expense of $20.1 million, $14.7 million, and $12.1 million, respectively. A summary of the status of the Company's nonvested restricted shares as of September 30, 2015 and changes during the fiscal year ended September 30, 2015 is presented below: Restricted Shares Weighted Average Grant Date Fair Value (000s) Nonvested at September 30, 2014 $ Granted $ Vested ) $ Forfeited ) $ ​ ​ ​ ​ ​ ​ ​ ​ Nonvested at September 30, 2015 $ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ During the fiscal years ended September 30, 2015, 2014, and 2013, the total fair values of restricted shares vested were $10.9 million, $10.5 million, and $9.7 million, respectively. Expected future compensation expense relating to the 0.9 million restricted shares outstanding as of September 30, 2015 is $18.6 million, which will be recognized over a weighted average period of 1.0 years. Performance Stock Units Performance stock units are granted to certain executive employees under the Plan, which represent Common Stock potentially issuable in the future. Performance stock units vest at the end of a three-year performance period based on achievement of specific performance goals. Based on the extent to which the targets are achieved, vested shares may range from 0 percent to 150 percent of the target award amount. The fair value of performance stock units is determined by the grant date market price of the Company's Common Stock and the compensation expense associated with nonvested performance stock units is dependent on the Company's periodic assessment of the probability of the targets being achieved and its estimate of the number of shares that will ultimately be issued. During the fiscal years ended September 30, 2015, 2014 and 2013, the Company recognized $10.6 million, $6.8 million, and $3.7 million of compensation expense, respectively, related to these performance stock units. A summary of the status of the Company's nonvested performance stock units as of September 30, 2015 and changes during the fiscal year ended September 30, 2015 is presented below (based on target award amounts). Performance Stock Units Weighted Average Grant Date Fair Value (000s) Nonvested at September 30, 2014 $ Granted $ Vested ) $ ​ ​ ​ ​ ​ ​ ​ ​ Nonvested at September 30, 2015 $ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Employee Stock Purchase Plan The AmerisourceBergen Corporation Employee Stock Purchase Plan provides for an aggregate of 4,000,000 shares of Common Stock that may be sold to eligible employees (generally defined as employees with at least 30 days of service with the Company). The participants may elect to have the Company withhold up to 25% of base salary to purchase shares of the Company's Common Stock at a price equal to 95% of the fair market value of the stock on the last business day of each six-month purchase period. Each participant is limited to $25,000 of purchases during each calendar year. During the fiscal years ended September 30, 2015, 2014, and 2013, the Company acquired 53,434 shares, 68,700 shares, and 93,813 shares, respectively, from the open market for issuance to participants in this plan. As of September 30, 2015, the Company has withheld $1.4 million from eligible employees for the purchase of additional shares of Common Stock.

Leases and Other Commitments

Leases and Other Commitments	12 Months Ended
	Sep. 30, 2015
Commitments and Contingencies Disclosure [Abstract]
Commitments Disclosure [Text Block]	Note 11. Leases and Other Commitments At September 30, 2015, future minimum payments totaling $374.6 million under noncancelable operating leases with remaining terms of more than one fiscal year were due as follows: 2016 — $74.2 million; 2017 — $63.3 million; 2018 — $56.6 million; 2019 — $45.7 million; 2020 — $36.6 million; and thereafter — $98.2 million. In the normal course of business, operating leases are generally renewed or replaced by other leases. Certain operating leases include escalation clauses. Total rental expense was $88.9 million in fiscal 2015, $81.8 million in fiscal 2014, and $79.6 million in fiscal 2013. The Company outsources to IBM Global Services ("IBM") a significant portion of its corporate and AmerisourceBergen Drug Corporation information technology activities. The remaining commitment under the Company's arrangement, as amended in June 2015, which expires in June 2018, is approximately $77.6 million as of September 30, 2015, of which $38.9 million represents the Company's commitment in fiscal 2016.

Employee Severance, Litigation,

Employee Severance, Litigation, and Other	12 Months Ended
	Sep. 30, 2015
Restructuring Charges Abstract
Restructuring and Related Activities Disclosure Text Block	Note 12. Employee Severance, Litigation and Other The following table illustrates the charges incurred by the Company relating to employee severance, litigation and other for the three fiscal years ended September 30, 2015 (in thousands): 2015 2014 2013 Employee severance and other $ $ $ Deal-related transaction costs ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Total employee severance, litigation and other $ $ $ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ During fiscal 2013, the Company incurred $23.0 million of deal-related transaction costs (primarily related to professional fees with respect to the WBA transaction) and $0.5 million of employee severance and other related costs. During fiscal 2014, the Company incurred $6.3 million of deal-related transaction costs and $1.9 million of employee severance and other related costs. During fiscal 2015, the Company incurred $32.6 million of deal-related transaction costs (primarily related to professional fees in connection with the MWI acquisition) and $5.3 million of employee severance and other related costs. Employees receive their severance benefits over a period of time, generally not in excess of 12 months, or in the form of a lump-sum payment.

Legal Matters and Contingencies

Legal Matters and Contingencies	12 Months Ended
	Sep. 30, 2015
Legal Matters and Contingencies [Abstract]
Legal Matters and Contingencies [Text Block]	Note 13. Legal Matters and Contingencies In the ordinary course of its business, the Company becomes involved in lawsuits, administrative proceedings, government subpoenas, and government investigations, including antitrust, commercial, environmental, product liability, intellectual property, regulatory, employment discrimination, and other matters. Significant damages or penalties may be sought from the Company in some matters, and some matters may require years for the Company to resolve. The Company establishes reserves based on its periodic assessment of estimates of probable losses. There can be no assurance that an adverse resolution of one or more matters during any subsequent reporting period will not have a material adverse effect on the Company's results of operations for that period or on the Company's financial condition. Qui Tam Matters The qui tam provisions of the federal civil False Claims Act and various state and local civil False Claims Acts permit a private person, known as a "relator" or whistleblower, to file civil actions under these statutes on behalf of the federal, state and local governments. Qui tam complaints are initially filed by the relator under seal (or on a confidential basis) and the filing of the complaint imposes obligations on government authorities to investigate the allegations in the complaint and to determine whether or not to intervene in the action. Qui tam complaints remain sealed until the court in which the case was filed orders otherwise. The Company has learned that there are filings in one or more federal district courts, including a qui tam complaint filed by one of its former employees, that are under seal and may involve allegations against the Company (and/or subsidiaries or businesses of the Company, including its group purchasing organization for oncologists and its oncology distribution business) relating to its distribution of certain pharmaceutical products to providers. Subpoenas and Ongoing Investigations From time to time, the Company receives subpoenas or requests for information from various government agencies relating to the Company's business or to the business of a customer, supplier or other industry participant. The Company generally responds to such subpoenas and requests in a cooperative manner. These responses often require time and effort and can result in considerable costs being incurred by the Company. Most of these matters are resolved without incident; however, such subpoenas or requests 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 substantial settlements. Since fiscal 2012, the Company and AmerisourceBergen Specialty Group ("ABSG") have been responding to subpoenas from the United States Attorney's Office for the Eastern District of New York ("USAO-EDNY") requesting production of documents and information relating to ABSG's oncology distribution center and former pharmacy in Dothan, Alabama (including the practices and procedures of the former pharmacy's pre-filled syringe program), its group purchasing organization for oncologists, and intercompany transfers of certain oncology products, which the Company believes could be related in whole or in part to one or more of the qui tam actions that remain under seal. The Company continues to engage in dialogue with the USAO-EDNY. In fiscal 2012, the Company's subsidiary, AmerisourceBergen Drug Corporation ("ABDC"), received a subpoena from the United States Attorney's Office in New Jersey (the "USAO-NJ") in connection with a grand jury proceeding requesting documents concerning ABDC's program for controlling and monitoring diversion of controlled substances into channels other than for legitimate medical, scientific, and industrial purposes. ABDC also received a subpoena from the Drug Enforcement Administration ("DEA") in connection with the matter. In addition to requesting information on ABDC's diversion control program generally, the subpoenas also request additional information related to electronically stored information and documents concerning specific customers' purchases of controlled substances. Since fiscal 2012, ABDC has received and responded to a number of subpoenas from both the USAO-NJ and the DEA requesting additional information, including for grand jury testimony and related documents concerning DEA audits. The Company continues to engage in dialogue with the USAO-NJ. Since fiscal 2013, the Company or ABDC has received subpoenas from the United States Attorney's Office in the District of Kansas and the United States Attorney's Office in the Northern District of Ohio in connection with grand jury proceedings requesting documents concerning ABDC's program for controlling and monitoring diversion of controlled substances into channels other than for legitimate medical, scientific and industrial purposes. As in the New Jersey matter described above, in addition to requesting information on ABDC's diversion control program generally, the subpoenas have also requested documents concerning specific customers' purchases of controlled substances. The Company is in the process of responding to the subpoenas and requests for information. The Company cannot predict the outcome of these ongoing investigations, or the impact on the Company as a result of these matters, which may include settlements in significant amounts that are not currently estimable, limitations on the Company's conduct, the imposition of corporate integrity obligations and/or other civil and criminal penalties. State Proceedings In June 2012, the Attorney General of the State of West Virginia ("West Virginia") filed complaints, which have been amended, in the Circuit Court of Boone County, West Virginia, against a number of pharmaceutical wholesale distributors, including the Company's subsidiary, ABDC, alleging, among other claims, that the distributors failed to provide effective controls and procedures to guard against diversion of controlled substances for illegitimate purposes in West Virginia, acted negligently by distributing controlled substances to pharmacies that serve individuals who abuse controlled substances, and failed to report suspicious orders of uncontrolled substances in accordance with state regulations. In addition to monetary damages and injunctive and other equitable relief, West Virginia is seeking to require the defendants to fund a medical monitoring treatment program. On April 6, 2015, ABDC filed a motion to dismiss, which was subsequently denied. On October 23, 2015, ABDC, together with all other defendants, filed a writ of prohibition, and on October 30, 2015, ABDC filed an answer to West Virginia's second amended complaint. ABDC is vigorously defending itself and cannot predict the outcome of this matter.

Litigation Settlements

Litigation Settlements	12 Months Ended
	Sep. 30, 2015
Litigation Settlements [Abstract]
Litigation Settlements [Text Block]	Note 14. Litigation Settlements Antitrust Settlements Numerous class action lawsuits have been filed against certain brand pharmaceutical manufacturers alleging that the manufacturer, by itself or in concert with others, took improper actions to delay or prevent generic drugs from entering the market. The Company has not been a named plaintiff in any of these class actions, but has been a member of the direct purchasers' class (i.e., those purchasers who purchase directly from these pharmaceutical manufacturers). None of the class actions has gone to trial, but some have settled in the past with the Company receiving proceeds from the settlement funds. During the fiscal years ended September 30, 2015, 2014, and 2013, the Company recognized gains of $65.5 million, $24.4 million, and $22.9 million, respectively, relating to the above-mentioned class action lawsuits. These gains, which are net of attorney fees and estimated payments due to other parties, were recorded as reductions to cost of goods sold in the Company's consolidated statements of operations.

Business Segment Information

Business Segment Information	12 Months Ended
	Sep. 30, 2015
Business Segment Information [Abstract]
Business Segment Information [Text Block]	Note 15. Business Segment Information The Company is organized based upon the products and services it provides to its customers. The Company's operations are comprised the Pharmaceutical Distribution reportable segment and Other. The Pharmaceutical Distribution reportable segment consists of the AmerisourceBergen Drug Corporation ("ABDC") and AmerisourceBergen Specialty Group ("ABSG") operating segments. Other consists of the AmerisourceBergen Consulting Services ("ABCS"), World Courier Group, Inc. ("World Courier") and MWI Veterinary Supply, Inc. ("MWI") operating segments. The Company has aggregated the operating segments of ABDC and ABSG into one reportable segment, the Pharmaceutical Distribution segment. The results of operations of the ABCS, World Courier and MWI operating segments are not significant enough to require separate reportable segment disclosure, and therefore have been included in Other for the purpose of reportable segment presentation. The Company's ability to aggregate ABDC and ABSG into one reportable segment was based on the following: • the objective and basic principles of ASC 280; • the aggregation criteria as noted in ASC 280; and • the fact that ABDC and ABSG have similar economic characteristics. The chief operating decision maker ("CODM") for the Company is the President and Chief Executive Officer of the Company whose function is to allocate resources to, and assess the performance of, the ABDC and ABSG operating segments. ABDC and ABSG each have an executive who functions as an operating segment manager whose role includes reporting directly to the President and Chief Executive Officer of the Company on their respective operating segment's business activities, financial results and operating plans. The businesses of the Pharmaceutical Distribution operating segments are similar in that they service both healthcare providers and pharmaceutical manufacturers in the pharmaceutical supply channel. The distribution of pharmaceutical drugs has historically represented more than 95% of the Company's revenues. ABDC and ABSG each operate in a high volume and low margin environment and, as a result, their economic characteristics are similar. Each operating segment warehouses and distributes products in a similar manner. Additionally, each operating segment is subject, in whole or in part, to the same extensive regulatory environment under which the pharmaceutical distribution industry operates. ABDC distributes a comprehensive offering of brand-name and generic pharmaceuticals (including specialty pharmaceutical products), over-the-counter healthcare products, home healthcare supplies and equipment, and related services to a wide variety of healthcare providers, including acute care hospitals and health systems, independent and chain retail pharmacies, mail order pharmacies, medical clinics, long-term care and other alternate site pharmacies and other customers. ABDC also provides pharmacy management, staffing and other consulting services; and supply management software to a variety of retail and institutional healthcare providers. Additionally, ABDC delivers packaging solutions to institutional and retail healthcare providers. ABSG, through a number of operating businesses, provides distribution and other services to physicians who specialize in a variety of disease states, especially oncology, and to other healthcare providers, including hospitals and dialysis clinics. ABSG also distributes plasma and other blood products, injectible pharmaceuticals, vaccines, and other specialty products. Additionally, ABSG provides third party logistics and outcomes research, and other services for biotechnology and other pharmaceutical manufacturers. The Company's use of the terms "specialty" and "specialty pharmaceutical products" refers to drugs used to treat complex diseases, such as cancer, diabetes, and multiple sclerosis. Specialty pharmaceutical products are part of complex treatment regimens for serious conditions and diseases that generally require ongoing clinical monitoring. The Company believes the terms "specialty" and "specialty pharmaceutical products" are used consistently by industry participants and its competitors. However, the Company cannot be certain that other distributors of specialty products define these and other similar terms in exactly the same manner as the Company does. Both ABDC and ABSG distribute specialty drugs to their customers, with the principal difference between these two operating segments being that ABSG operates distribution facilities that focus primarily on complex disease treatment regimens. Therefore, a product distributed from one of ABSG's distribution facilities results in revenue reported under ABSG, and a product distributed from one of ABDC's distribution centers results in revenue reported under ABDC. Essentially, all of ABSG's sales consist of specialty pharmaceutical products. ABDC sales of specialty pharmaceutical products have historically been a relatively small component of its overall revenue. As noted above, Other consists of the ABCS, World Courier and MWI operating segments. ABCS, through a number of operating businesses, provides commercialization support services including reimbursement support programs, outcomes research, contract field staffing, patient assistance and co-pay assistance programs, adherence programs, risk mitigation services, and other market access programs to pharmaceutical and biotechnology manufacturers. World Courier, which operates in over 50 countries, is a leading global specialty transportation and logistics provider for the biopharmaceutical industry. MWI is a leading animal health distribution company in the United States and in the United Kingdom. MWI sells pharmaceuticals, vaccines, parasiticides, diagnostics, micro feed ingredients, and various other products to customers in both the companion animal and production animal markets. The following tables illustrate reportable segment information for the periods indicated (in thousands): Revenue Fiscal year ended September 30, 2015 2014 2013 Pharmaceutical Distribution $ $ $ Other Intersegment eliminations ) ) ) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Revenue $ $ $ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Intersegment eliminations primarily represent the elimination of certain ABCS sales to the Pharmaceutical Distribution reportable segment. Segment Operating Income Fiscal year ended September 30, 2015 2014 2013 Pharmaceutical Distribution $ $ $ Other ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Total segment operating income $ $ $ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ The following table reconciles total segment operating income to income from continuing operations before income taxes (in thousands): Income From Continuing Operations Before Income Taxes Fiscal year ended September 30, 2015 2014 2013 Total segment operating income $ $ $ Gains on antitrust litigation settlements LIFO expense ) ) ) Acquisition-related intangibles amortization ) ) ) Warrant expense ) ) ) Employee severance, litigation and other ) ) ) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Operating income Other loss (income) ) Impairment charge on equity investment — — Interest expense, net Loss on early retirement of debt — — ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Income from continuing operations before income taxes $ $ $ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Segment operating income is evaluated by the chief operating decision maker of the Company before gains on antitrust litigation settlements; LIFO expense; acquisition-related intangibles amortization; Warrant expense; employee severance, litigation and other; other loss (income); impairment charge on equity investment; interest expense, net; and loss on early retirement of debt. All corporate office expenses are allocated to each operating segment. Assets At September 30, 2015 2014 Pharmaceutical Distribution $ $ Other ​ ​ ​ ​ ​ ​ ​ ​ Total assets $ $ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ The CODM does not review assets by operating segment for purposes of assessing performance or allocating resources. Depreciation & Amortization Fiscal year ended September 30, 2015 2014 2013 Pharmaceutical Distribution $ $ $ Other Acquisition-related intangibles amortization ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Total depreciation and amortization $ $ $ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Depreciation and amortization includes depreciation and amortization of property and equipment and intangible assets, but excludes amortization of deferred financing costs and other debt-related items which are included in interest expense. Capital Expenditures Fiscal year ended September 30, 2015 2014 2013 Pharmaceutical Distribution $ $ $ Other ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Total capital expenditures $ $ $ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​

Fair Value of Financial Instrum

Fair Value of Financial Instruments	12 Months Ended
	Sep. 30, 2015
Fair Value of Financial Instruments [Abstract]
Fair Value of Financial Instruments [Text Block]	Note 16. Fair Value of Financial Instruments The recorded amounts of the Company's cash and cash equivalents, accounts receivable and accounts payable at September 30, 2015 and 2014 approximate fair value based upon the relatively short-term nature of these financial instruments. Within cash and cash equivalents, the Company had no investments in money market accounts as of September 30, 2015. The Company had $400.0 million of investments in money market accounts as of September 30, 2014. The fair values of the money market accounts were determined on unadjusted quoted prices in active markets for identical assets, otherwise known as Level 1 inputs. The Company had $213.1 million of investment securities available-for-sale, $126.9 million of which are within cash and cash equivalents, at September 30, 2015. The fair values of the investments were based on inputs other than quoted prices, otherwise known as Level 2 inputs. The investments consist of fixed-income securities with maturities ranging from October 2015 to July 2017. The fair value and the amortized cost of the investments was $213.1 million at September 30, 2015. The recorded amount of long-term debt (see Note 7) and the corresponding fair value as of September 30, 2015 were $3,493.0 million and $3,515.1 million, respectively. The recorded amount of long-term debt and the corresponding fair value as of September 30, 2014 were $1,995.6 million and $2,056.6 million, respectively. The fair values of long-term debt were determined based on quoted market prices, otherwise known as Level 2 inputs.

Quarterly Financial Information

Quarterly Financial Information (Unaudited)	12 Months Ended
	Sep. 30, 2015
Quarterly Financial Information Disclosure [Abstract]
Quarterly Financial Information Text Block	Note 17. Quarterly Financial Information (Unaudited) Fiscal Year Ended September 30, 2015 First Quarter Second Quarter Third Quarter Fourth Quarter Fiscal Year (In thousands, except per share amounts) Revenue $ $ $ $ $ Gross profit(a) $ $ $ $ $ Distribution, selling and administrative expenses, depreciation, and amortization Warrant expense ) ) Employee severance, litigation and other ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Operating (loss) income $ ) $ ) $ $ $ Net (loss) income $ ) $ ) $ $ $ ) Earnings per share operations: Basic $ ) $ ) $ $ $ ) Diluted $ ) $ ) $ $ $ ) (a) The second, third and fourth quarters of fiscal 2015 include gains of $21.5 million, $43.6 million, and $0.4 million, respectively, from antitrust litigation settlements. The first, second, third, and fourth quarters of fiscal 2015 include LIFO charges of $144.0 million, $151.1 million, $158.7 million, and $88.9 million, respectively. Fiscal Year Ended September 30, 2014 First Quarter Second Quarter Third Quarter Fourth Quarter Fiscal Year (In thousands, except per share amounts) Revenue $ $ $ $ $ Gross profit(a) $ $ $ $ $ Distribution, selling and administrative expenses, depreciation and amortization Warrant expense Employee severance, litigation and other ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Operating income $ $ $ $ $ Income (loss) from continuing operations $ $ $ ) $ $ Loss from discontinued operations, net of tax(b) ) — — — ) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Net income (loss) $ $ $ ) $ $ Earnings per share from continuing operations: Basic $ $ $ ) $ $ Diluted $ $ $ ) $ $ Earnings per share: Basic $ $ $ ) $ $ Diluted $ $ $ ) $ $ (a) The first, second, and third quarters of fiscal 2014 include gains of $21.0 million, $0.8 million, and $2.5 million, respectively, from antitrust litigation settlements. The first, second, third, and fourth quarters of fiscal 2014 include LIFO charges of $57.6 million, $102.8 million, $133.2 million, and $54.4 million, respectively. (b) Includes the impact of a final purchase price working capital adjustment related to the divestiture of ABCC (see Note 4).

Subsequent Events

Subsequent Events	12 Months Ended
	Sep. 30, 2015
Subsequent Events [Abstract]
Subsequent Events [Text Block]	Note 18. Subsequent Events Acquisition On November 6, 2015, the Company acquired PharMEDium Healthcare Holdings, Inc. ("PharMEDium"), a privately held leading national provider of outsourced compounded sterile preparations ("CSPs") to acute care hospitals in the United States for $2.7 billion in cash, which included certain purchase price adjustments. The Company financed the transaction through a combination of cash and long-term debt. In November 2015, the Company entered into a $1.0 billion variable rate term loan, which matures in November 2020. This term loan is subject to quarterly principal payments of $25 million on the last business day of each March, June, September and December, commencing in March 2016. The remaining unpaid principal amount of the term loan is due on the maturity date. The term loan will bear interest at a rate equal either to a base rate, plus a margin, or a LIBOR, plus a margin. The margin will be based on our public debt ratings and ranges from 0 basis points to 25 basis points over a base rate, and ranges from 75 basis points to 125 basis points over LIBOR. The term loan contains similar covenants to the Company's previously existing Term Loan, with which we are compliant as of September 30, 2015. The Company used the proceeds from the term loan to repay funding sources used to finance a portion of the cash consideration paid in connection with the acquisition of PharMEDium. Dividend Increase In November 2015, the Company's board of directors increased the quarterly dividend paid on Common Stock by 17% and declared a regular quarterly cash dividend of $0.34 payable on December 1, 2015 to shareholders of record on November 16, 2015. Income Taxes In March 2013, the Company issued Warrants (as defined in Note 8) in connection with various agreements and arrangements with WBA. At that time, the Company determined that the Warrants had a fair value of $242.4 million on the date of issuance, which approximated the tax deductible amount that would be deducted ratably on the Company's tax return over the 10-year term of the various agreements, and that any value in excess of the initial fair value of the Warrants on the date of issuance would not be tax deductible. On November 23, 2015, the Company received a private letter ruling from the Internal Revenue Service determining that the Company may recognize the tax consequences of the Warrants when they are exercised. As a result, the Company will be entitled to an income tax deduction when the Warrants are exercised for the Warrant expense equal to the difference between the fair value of the Warrants on the date of exercise and the strike price to be paid to exercise the Warrants. As a result of the receipt of the private letter ruling, in the quarter ending December 31, 2015, the Company will recognize in earnings a tax benefit adjustment of approximately $456 million representing the estimated tax deduction for the increase in the value of the Warrants since the inception of the arrangement through September 30, 2015. Additionally, the Company also expects to recognize the tax impact of the change in fair value of the Warrants, through the date of exercise, within the Company's results of earnings subsequently at the applicable tax rate, currently estimated to be 36.5%.

Schedule II Valuation and Quali

Schedule II Valuation and Qualifying Accounts	12 Months Ended
	Sep. 30, 2015
Valuation and Qualifying Accounts [Abstract]
Schedule of Valuation and Qualifying Accounts Disclosure Text Block	AMERISOURCEBERGEN CORPORATION AND SUBSIDIARIES SCHEDULE II — VALUATION AND QUALIFYING ACCOUNTS Description Balance at Beginning of Period Charged to Costs and Expenses(1) Deductions- Describe(2) Balance at End of Period(3) (In thousands) Year Ended September 30, 2015 Allowances for returns and doubtful accounts $ $ $ ) $ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended September 30, 2014 Allowances for returns and doubtful accounts $ $ $ ) $ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended September 30, 2013 Allowances for returns and doubtful accounts $ $ $ ) $ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ (1) Represents the provision for returns and doubtful accounts. (2) Represents accounts receivable written off during year, net of recoveries and reductions to the returns allowance. (3) Includes an allowance for doubtful accounts for long-term accounts receivable within the Other Assets on the consolidated balance sheets of $23,991, $23,668 and $0 as of September 30, 2015, 2014 and 2013, respectively.

Summary of Significant Accoun31

Summary of Significant Accounting Policies (Policies)	12 Months Ended
	Sep. 30, 2015
Summary of Significant Accounting Policies [Abstract]
Nature of Operations	AmerisourceBergen Corporation (the "Company") is one of the largest global pharmaceutical sourcing and distribution services companies, helping both healthcare providers and pharmaceutical and biotech manufacturers improve patient access to products and enhance patient care. The Company delivers innovative programs and services designed to increase the effectiveness and efficiency of the pharmaceutical supply chain in both human and animal health.
Consolidation Policy Text Block	The accompanying consolidated financial statements include the accounts of the Company and its wholly-owned subsidiaries as of the dates and for the fiscal years indicated. All intercompany accounts and transactions have been eliminated in consolidation.
Use of Estimates, Policy [Policy Text Block]	The preparation of financial statements in conformity with U.S. generally accepted accounting principles requires management to make estimates and assumptions that affect amounts reported in the financial statements and accompanying notes. Actual amounts could differ from these estimated amounts due to uncertainties inherent in such estimates. Management periodically evaluates estimates used in the preparation of the financial statements for continued reasonableness.
New Accounting Pronouncements Policy [Policy Text Block]	In May 2014, the Financial Accounting Standards Board issued Accounting Standards Update No. 2014-09, "Revenue from Contracts with Customers (Topic 606)" ("ASU 2014-09"). ASU 2014-09 supersedes the revenue recognition requirements in Accounting Standards Codification 605 — Revenue Recognition, and most industry-specific guidance throughout the Codification. ASU 2014-09 outlines a single comprehensive model for entities to use in accounting for revenue arising from contracts with customers. The standard's core principle is that a company should recognize revenue to depict the transfer of promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services. ASU 2014-09 was originally scheduled to be effective for annual reporting periods beginning after December 15, 2016, including interim periods within those reporting periods. In July 2015, the Financial Accounting Standards Board deferred the effective date of ASU 2014-09 by one year. Entities are permitted to adopt the standard as early as the original public entity effective date, and either full or modified retrospective application is required. The Company has not yet selected an adoption date or a transition method and is currently evaluating the impact of adopting this new accounting guidance. In April 2015, the Financial Accounting Standards Board issued Accounting Standards Update No. 2015-03, Interest — Imputation of Interest (Subtopic 835-30): Simplifying the Presentation of Debt Issuance Costs ("ASU 2015-03"). ASU 2015-03 is the result of the Financial Accounting Standards Board's simplification initiative intended to improve U.S. GAAP by reducing costs and complexity while maintaining or enhancing the usefulness of related financial statement information. ASU 2015-03 specifies that debt issuance costs related to a note shall be reported in the balance sheet as a direct reduction from the face amount of the note. ASU 2015-03 is effective for annual reporting periods beginning after December 15, 2015, and interim periods within those fiscal years. ASU 2015-03 will require the Company to reclassify its capitalized debt issuance costs currently recorded as assets on the consolidated condensed balance sheets. ASU 2015-03 will have no effect on the Company's results of operations or liquidity. As of September 30, 2015, there are no other recently issued accounting standards that will have a material impact on the Company's financial position or results of operation upon their adoption.
Business Combinations Policy	The purchase price of an acquired company, including the fair value of contingent consideration, is allocated between tangible and intangible assets acquired and liabilities assumed from the acquired business based on their estimated fair values, with the residual of the purchase price recorded as goodwill. The results of operations of the acquired businesses are included in the Company's operating results from the dates of acquisition.
Cash and Cash Equivalents Policy Text Block	The Company considers all highly liquid investments with original maturities of three months or less to be cash equivalents. The carrying value of cash equivalents approximates fair value.
Receivables Policy Text Block	The Company sells its merchandise inventories to a large number of customers in the healthcare industry that include institutional and retail healthcare providers. Institutional healthcare providers include acute care hospitals, health systems, mail order pharmacies, long-term care and other alternate care pharmacies and providers of pharmacy services to such facilities, and physician offices. Retail healthcare providers include national and regional retail drugstore chains, independent community pharmacies, pharmacy departments of supermarkets and mass merchandisers, and veterinarians. The financial condition of the Company's customers can be affected by changes in government reimbursement policies as well as by other economic pressures in the healthcare industry. The Company's trade accounts receivable are exposed to credit risk. The Company's largest customer in fiscal 2015, Walgreens Boots Alliance, Inc. ("WBA"), accounted for 30% of revenue and represented approximately 40% of accounts receivable, net as of September 30, 2015. Express Scripts, Inc., the Company's second largest customer in fiscal 2015, accounted for 16% of revenue and represented approximately 10% of accounts receivable, net as of September 30, 2015. The Company generally does not require collateral for trade receivables. In determining the appropriate allowance for doubtful accounts, the Company considers a combination of factors, such as the aging of trade receivables, industry trends, its customers' financial strength, credit standing, and payment and default history. Changes in these factors, among others, may lead to adjustments in the Company's allowance for doubtful accounts. The calculation of the required allowance requires judgment by Company management as to the impact of those and other factors on the ultimate realization of its trade receivables. Each of the Company's business units performs ongoing credit evaluations of its customers' financial condition and maintains reserves for probable bad debt losses based on historical experience and for specific credit problems when they arise. There were no significant changes to this process during the fiscal years ended September 30, 2015, 2014, and 2013 and bad debt expense was computed in a consistent manner during these periods. The bad debt expense for any period presented is equal to the changes in the period end allowance for doubtful accounts, net of write-offs, recoveries and other adjustments. The Company maintains cash and cash equivalents with several financial institutions. Deposits held with banks may exceed the amount of insurance provided on such deposits. These deposits may be redeemed upon demand, and are maintained with financial institutions with reputable credit, and, therefore, bear minimal credit risk. The Company seeks to mitigate such risks by monitoring the risk profiles of these counterparties. The Company also seeks to mitigate risk by monitoring the investment strategy of money market accounts that it is invested in, which are classified as cash equivalents.
Commitments and Contingencies Policy Text Block	Loss Contingencies: In the ordinary course of its business, the Company becomes involved in lawsuits, administrative proceedings, government subpoenas, and government investigations, including antitrust, commercial, environmental, product liability, intellectual property, regulatory, employment discrimination, and other matters. Significant damages or penalties may be sought from the Company in some matters, and some matters may require years for the Company to resolve. The Company records a liability when it is probable that a loss has been incurred and the amount is reasonably estimable. The Company also performs an assessment of the materiality of loss contingencies where a loss is either not probable or it is reasonably possible that a loss could be incurred in excess of amounts accrued. If a loss or an additional loss has at least a reasonable possibility of occurring and the impact on the financial statements would be material, the Company provides disclosure of the loss contingency in the footnotes to its financial statements. The Company reviews 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 the range of the loss can be made (see Note 13). Gain Contingencies: The Company records gain contingencies when they are realized. Gains from antitrust litigation settlements are realized upon the receipt of cash and recorded as a reduction to cost of goods sold because they represent a recovery of amounts historically paid to manufacturers to originally acquire the pharmaceuticals that were the subject of the antitrust litigation settlements (see Note 14).
Derivatives Policy Text Block	The Company records all derivative financial instruments on the balance sheet at fair value and complies with established criteria for designation and effectiveness of hedging relationships. The Company's policy prohibits it from entering into derivative financial instruments for speculative or trading purposes. The Company had one foreign currency denominated contract outstanding that hedges the foreign currency exchange risk of a C$46.9 million note outstanding as of September 30, 2015.
Equity Method Investments Policy	The Company uses the equity method of accounting for its investments in entities in which it has significant influence; generally, this represents an ownership interest of between 20% and 50% (see Note 3). Declines in value that are determined to be other-than-temporary are recorded as impairment charges as a component of earnings in the period in which that determination is made. The Company recorded an impairment charge of $30.6 million in fiscal 2015 related to its minority interest in a pharmaceutical wholesaler in Brazil. The impairment charge was based on the determination by the Company that the decline in the pharmaceutical wholesaler's stock price from the date on which the investment was made to September 30, 2015 was other-than-temporary. There were no impairment charges on equity investments in fiscal 2014 or 2013.
Foreign Currency Transactions and Translations Policy Text Block	The functional currency of the Company's foreign operations is generally the applicable local currency. Assets and liabilities are translated into U.S. dollars using the current exchange rates in effect at the balance sheet date, while revenues and expenses are translated at the weighted average exchange rates for the period. The resulting translation adjustments are recorded as a component of accumulated other comprehensive loss within stockholders' equity.
Goodwill and Intangible Assets Policy Text Block	Goodwill and other intangible assets with indefinite lives, primarily trademarks and trade names, are not amortized; rather, they are tested for impairment at least annually. For the purpose of these impairment tests, the Company can elect to perform a qualitative analysis to determine if it is more likely than not that the fair values of its reporting units and indefinite lived intangible assets are less than the respective carrying values of those reporting units and indefinite lived intangible assets. The Company elected to bypass performing the qualitative screen and went directly to performing the first step quantitative analysis of the goodwill and indefinite lived intangible asset impairment tests in the current year. The Company may elect to perform the qualitative analysis in future periods. The first step in the quantitative process for the goodwill impairment test is to compare the carrying amount of the reporting unit's net assets to the fair value of the reporting unit. If the fair value exceeds the carrying value, no further evaluation is required and no impairment loss is recognized. If the carrying amount exceeds the fair value, then the second step must be completed, which involves allocating the fair value of the reporting unit to each asset and liability, with the excess being implied goodwill. An impairment loss occurs if the amount of the recorded goodwill exceeds the implied goodwill. The Company would be required to record any such impairment losses. The Company identifies its reporting units at the operating segment level. Generally, goodwill arises from acquisitions of specific operating companies and is assigned to the reporting unit in which a particular operating company resides. The Company utilizes a combination of income and market-based approaches to value its reporting units. The income approach to valuation relies on a discounted cash flow analysis to determine the fair value of each reporting unit, which considers forecasted cash flows discounted at an appropriate discount rate. The Company believes that market participants would use a discounted cash flow analysis to determine the fair value of its reporting units in a sale transaction. The annual goodwill impairment test requires the Company to make a number of assumptions and estimates concerning future levels of revenue growth, operating margins, depreciation, amortization and working capital requirements, which are based upon the Company's long-range plan. The discount rate is an estimate of the overall after-tax rate of return required by a market participant whose weighted average cost of capital includes both equity and debt, including a risk premium. While the Company uses the best available information to prepare its cash flow and discount rate assumptions, actual future cash flows or market conditions could differ significantly resulting in future impairment charges related to recorded goodwill balances. While there are always changes in assumptions to reflect changing business and market conditions, the Company's overall methodology and the population of assumptions used have remained unchanged. The impairment test for indefinite-lived intangibles other than goodwill (primarily trademarks and trade names) consists of a comparison of the fair value of the indefinite-lived intangible asset to the carrying value of the asset as of the impairment testing date. The Company estimates the fair value of its indefinite-lived intangibles using the relief from royalty method. The Company believes the relief from royalty method is a widely used valuation technique for such assets. The fair value derived from the relief from royalty method is measured as the discounted cash flow savings realized from owning such trademarks and trade names and not having to pay a royalty for their use. The Company completed its required annual impairment tests relating to goodwill and other intangible assets in the fiscal years ended September 30, 2015, 2014, and 2013, and, as a result, determined that there were no impairments. Finite-lived intangible assets are amortized using the straight-line method over the estimated useful lives of the assets.
Income Tax Policy Text Block	The Company accounts for income taxes using a method that requires recognition of deferred tax assets and liabilities for expected future tax consequences of temporary differences that currently exist between tax bases and financial reporting bases of the Company's assets and liabilities (commonly known as the asset and liability method). In assessing the ability to realize deferred tax assets, the Company considers whether it is more likely than not that some portion or all of the deferred tax assets will not be realized. The Company recognizes the tax benefit from an uncertain tax position only if it is more likely than not that the tax position will be sustained upon examination by the taxing authorities, including resolutions of any related appeals or litigation processes, based on the technical merits of the position. Tax benefits associated with uncertain tax positions that have met the recognition criteria are measured and recorded based on the highest probable outcome that is more than 50% likely to be realized after full disclosure and resolution of a tax examination.
Investment Securities Available-For-Sale Policy Text Block	All highly liquid investments with maturities of three months or less at the date of purchase are classified as cash equivalents. The Company's marketable debt securities have been classified and accounted for as available-for-sale. Management determines the appropriate classification of its investments at the time of purchase and reevaluates the classifications at each balance sheet date. The Company classifies its marketable debt securities as either short-term or long-term based on each instrument's underlying contractual maturity date. Marketable debt securities with maturities of 12 months or less are classified as short-term and marketable debt securities with maturities greater than 12 months are classified as long-term. The Company's marketable debt is carried at fair value, with unrealized gains and losses reported as a component of accumulated other comprehensive income in shareholders' equity, with the exception of unrealized losses believed to be other-than-temporary, which are reported in earnings in the current period. The cost of securities sold is based upon the specific identification method. As of September 30, 2015, the fair value of the Company's investment securities available-for-sale was $86.2 million, $50.8 million of which was within Prepaid Expenses and Other and $35.4 million of which was within Other Assets on the Company's consolidated balance sheets. The Company did not have any investment securities available-for-sale as of September 30, 2014.
Cost of Sales Vendor Allowances Policy	The Company accounts for fees and other incentives received from its suppliers, relating to the purchase or distribution of inventory, as a reduction to cost of goods sold. The Company considers these fees and other incentives to represent product discounts, and as a result, they are capitalized as product costs and relieved through cost of goods sold upon the sale of the related inventory.
Inventory Policy Text Block	Inventories are stated at the lower of cost or market. Cost for approximately 80% and 84% of the Company's inventories at September 30, 2015 and 2014, respectively, has been determined using the last-in, first-out (LIFO) method. If the Company had used the first-in, first-out (FIFO) method of inventory valuation, which approximates current replacement cost, inventories would have been approximately $1,424.6 million and $881.8 million higher than the amounts reported at September 30, 2015 and 2014, respectively. The Company recorded LIFO expense of $542.8 million, $348.1 million, and $277.0 million in fiscal 2015, 2014, and 2013, respectively. The annual LIFO provision is affected by changes in inventory quantities, product mix, and manufacturing pricing practices, which may be impacted by market and other external influences, many of which are difficult to predict. Changes to any of the above factors can have a material impact to the Company's annual LIFO provision.
Property Plant and Equipment Policy Text Block	Property and equipment are stated at cost and depreciated using the straight-line method over the estimated useful lives of the assets, which range from 3 to 40 years for buildings and improvements and from 3 to 10 years for machinery, equipment and other. The costs of repairs and maintenance are charged to expense as incurred. The Company capitalizes project costs relating to computer software developed or obtained for internal use when the activities related to the project reach the application development stage. Costs that are associated with preliminary stage activities, training, maintenance, and all other post-implementation stage activities are expensed as they are incurred. Software development costs are depreciated using the straight-line method over the estimated useful lives, which range from 3 to 10 years.
Revenue Recognition Policy Text Block	The Company recognizes revenue when persuasive evidence of an arrangement exists, product has been delivered or services have been rendered, the price is fixed or determinable and collectability is reasonably assured. Revenue as reflected in the accompanying consolidated statements of operations is net of estimated sales returns and allowances. The Company's customer sales return policy generally allows customers to return products only if the products can be resold at full value or returned to suppliers for full credit. The Company records an accrual for estimated customer sales returns at the time of sale to the customer. At September 30, 2015 and 2014, the Company's accrual for estimated customer sales returns was $841.3 million and $932.6 million, respectively. The Company reports the gross dollar amount of bulk deliveries to customer warehouses in revenue and the related costs in cost of goods sold. Bulk delivery transactions are arranged by the Company at the express direction of the customer, and involve either drop shipments from the supplier directly to customers' warehouse sites or cross-dock shipments from the supplier to the Company for immediate shipment to the customers' warehouse sites. The Company is a principal to these transactions because it is the primary obligor and has the ultimate and contractual responsibility for fulfillment and acceptability of the products purchased, and bears full risk of delivery and loss for products, whether the products are drop-shipped or shipped via cross-dock. The Company also bears full credit risk associated with the creditworthiness of any bulk delivery customer. As a result, the Company records bulk deliveries to customer warehouses as gross revenues. Gross profit earned by the Company on bulk deliveries was not material in any year presented.
Share-based Compensation Option and Incentive Plans Policy	The Company accounts for the compensation cost of all share-based payments at fair value and reports the related expense within distribution, selling and administrative expenses to correspond with the same line item as the cash compensation paid to employees. The benefits of tax deductions in excess of recognized compensation expense are reported as a financing cash flow ($88.1 million, $46.3 million, and $41.2 million for the fiscal years ended September 30, 2015, 2014, and 2013, respectively). The fair value of performance stock units is determined by the grant date market price of the Company's Common Stock and the compensation expense associated with nonvested performance stock units is dependent on the Company's periodic assessment of the probability of the targets being achieved and its estimate of the number of shares that will ultimately be issued.
Shipping and Handling Cost Policy Text Block	Shipping and handling costs include all costs to warehouse, pick, pack and deliver inventory to customers. These costs, which were $419.2 million, $348.3 million and $267.3 million for the fiscal years ended September 30, 2015, 2014, and 2013, respectively, are included in distribution, selling and administrative expenses.
Supplier Reserves Policy [Text Block]	The Company establishes reserves against amounts due from its suppliers relating to various price and rebate incentives, including deductions or billings taken against payments otherwise due them from the Company. These reserve estimates are established based on the judgment of Company management after carefully considering the status of current outstanding claims, historical experience with the suppliers, the specific incentive programs and any other pertinent information available to the Company. The Company evaluates the amounts due from its suppliers on a continual basis and adjusts the reserve estimates when appropriate based on changes in factual circumstances. The ultimate outcome of any outstanding claim may be different than the Company's estimate.
Warrant Accounting Policy [Text Block]	The Company accounts for the warrants issued to subsidiaries of WBA (collectively, the "Warrants") in accordance with the guidance for equity-based payments to non-employees. The various agreements and arrangements with WBA established various performance commitments that they must satisfy during the vesting periods of the Warrants, and if not fulfilled, the Company has the right to cancel the Warrants. Using a binomial lattice model approach, the fair value of the Warrants was initially measured at the date of issuance, and is being expensed over the three and four year vesting periods as an operating expense. The fair value of the Warrants are re-measured at the end of each quarterly reporting period, and an adjustment is recorded in the statement of operations to record the impact as if the newly measured fair value of the awards had been used in recognizing expense starting when the awards were originally issued and through the remeasurement date. In total, the Warrants were valued at $1,917.9 million as of September 30, 2015. The valuation of the Warrants considers the Company's Common Stock price and various assumptions, such as the volatility of the Company's Common Stock, the expected remaining life of the Warrants, the expected dividend yield, and the risk-free interest rate. As a result, future Warrant expense could fluctuate significantly (see Note 8).

Discontinued Operations (Tables

Discontinued Operations (Tables)	12 Months Ended
	Sep. 30, 2015
Discontinued Operation Income Loss From Discontinued Operation Disclosures Abstract
Schedule of Disposal Groups Including Discontinued Operations Income Statement Disclosures [Text Block]	Fiscal Year Ended September 30, (in thousands) 2015 2014 2013 Revenue $ — $ — $ Loss before income taxes $ — $ ) $ )

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Sep. 30, 2015
Income Taxes [Abstract]
Schedule of Income before Income Tax, Domestic and Foreign	The following illustrates domestic and foreign income from continuing operations before income taxes (in thousands): Fiscal year ended September 30, 2015 2014 2013 Domestic $ $ $ Foreign ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Total $ $ $ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​
Schedule of Components of Income Tax Expense (Benefit) [Table Text Block]	The income tax provision is as follows (in thousands): Fiscal Year Ended September 30, 2015 2014 2013 Current provision: Federal $ $ $ State and local Foreign ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Deferred provision: Federal State and local ) Foreign ) ) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Provision for income taxes $ $ $ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​
Schedule of Effective Income Tax Rate Reconciliation [Table Text Block]	Fiscal Year Ended September 30, 2015 2014 2013 Statutory U.S. federal income tax rate State and local income tax rate, net of federal tax benefit Foreign Warrants Valuation allowance — Other ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Effective income tax rate ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​
Schedule of Deferred Tax Assets and Liabilities [Table Text Block]	Significant components of the Company's deferred tax liabilities (assets) are as follows (in thousands): September 30, 2015 2014 Merchandise inventories $ $ Property and equipment Goodwill and other intangible assets Other ​ ​ ​ ​ ​ ​ ​ ​ Gross deferred tax liabilities ​ ​ ​ ​ ​ ​ ​ ​ Net operating loss and tax credit carryforwards ) ) Capital loss carryforwards ) ) Allowance for doubtful accounts ) ) Accrued expenses ) ) Employee and retiree benefits ) ) Stock options ) ) Warrants ) ) Other ) ) ​ ​ ​ ​ ​ ​ ​ ​ Gross deferred tax assets ) ) Valuation allowance for deferred tax assets ​ ​ ​ ​ ​ ​ ​ ​ Deferred tax assets, net of valuation allowance ) ) ​ ​ ​ ​ ​ ​ ​ ​ Net deferred tax liabilities $ $ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​
Summary of Income Tax Contingencies [Table Text Block]	A reconciliation of the beginning and ending amount of unrecognized tax benefits, excluding interest and penalties, in fiscal 2015, 2014, and 2013 is as follows (in thousands): Balance at September 30, 2012 $ Additions of tax positions of the current year Additions of tax positions of the prior years Additions of tax positions due to acquisitions Settlements with taxing authorities ) Expiration of statutes of limitations ) ​ ​ ​ ​ ​ Balance at September 30, 2013 Additions of tax positions of the current year Additions of tax positions of the prior years Reductions of tax positions of the prior years ) Settlements with taxing authorities ) Expiration of statutes of limitations ) ​ ​ ​ ​ ​ Balance at September 30, 2014 Additions of tax positions of the current year Reductions of tax positions of the prior years ) Settlements with taxing authorities ) Expiration of statutes of limitations ) ​ ​ ​ ​ ​ Balance at September 30, 2015 $ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​

Goodwill and Other Intangible34

Goodwill and Other Intangible Assets (Tables)	12 Months Ended
	Sep. 30, 2015
Goodwill and Other Intangible Assets [Abstract]
Schedule of Goodwill Text Block	Following is a summary of the changes in the carrying value of goodwill for the fiscal years ended September 30, 2015 and 2014 (in thousands): Pharmaceutical Distribution Other Total Goodwill at September 30, 2013 $ $ $ Goodwill recognized in connection with acquisitions — Foreign currency translation — ) ) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Goodwill at September 30, 2014 Goodwill recognized in connection with acquisitions Goodwill disposed in connection with divestitures ) ) ) Foreign currency translation — ) ) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Goodwill at September 30, 2015 $ $ $ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​
Schedule of Other Intangible Assets [Text Block]	Following is a summary of other intangible assets (in thousands): September 30, 2015 September 30, 2014 Gross Carrying Amount Accumulated Amortization Net Carrying Amount Gross Carrying Amount Accumulated Amortization Net Carrying Amount Indefinite-lived intangibles — trade names $ $ — $ $ $ — $ Finite-lived intangibles: Customer relationships ) ) Other ) ) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Total other intangible assets $ $ ) $ $ $ ) $ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​

Debt (Tables)

Debt (Tables)	12 Months Ended
	Sep. 30, 2015
Debt [Abstract]
Schedule of Debt Instruments Text Block	September 30, 2015 2014 (Dollars in thousands) Multi-currency revolving credit facility due 2019 $ — $ — Receivables securitization facility due 2017 — — Revolving credit note — — Overdraft facility — — Term loan — $600,000, 1.15% senior notes due 2017 $400,000, 4.875% senior notes due 2019 $500,000, 3.50% senior notes due 2021 $500,000, 3.40% senior notes due 2024 $500,000, 3.25% senior notes due 2025 — $500,000, 4.25% senior notes due 2045 — ​ ​ ​ ​ ​ ​ ​ ​ Total debt $ $ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​

Stockholders' Equity and Earn36

Stockholders' Equity and Earnings Per Share (Tables)	12 Months Ended
	Sep. 30, 2015
Stockholders Equity and Earnings per Share Tables [Abstract]
Schedule of Accumulated Other Comprehensive Income (Loss) [Table Text Block]	The following table illustrates the components of accumulated other comprehensive loss, net of income taxes, as of September 30, 2015 and 2014 (in thousands): September 30, 2015 2014 Pension and postretirement adjustments (See Note 9) $ ) $ ) Foreign currency translation ) ) Other ) ) ​ ​ ​ ​ ​ ​ ​ ​ Total accumulated other comprehensive loss $ ) $ ) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​
Schedule of Weighted Average Number of Shares [Table Text Block]	The following table (in thousands) illustrates the components of diluted weighted average shares outstanding: September 30, 2015 2014 2013 Weighted average common shares outstanding — basic Effect of dilutive securities — stock options, restricted stock, and restricted stock units — Dilutive effect of Warrants — — ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Weighted average common shares outstanding — diluted ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​

Share-Based Compensation (Table

Share-Based Compensation (Tables)	12 Months Ended
	Sep. 30, 2015
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Schedule of Share-based Payment Award, Stock Options, Valuation Assumptions [Table Text Block]	Fiscal Year Ended September 30, 2015 2014 2013 Risk-free interest rate Expected dividend yield Volatility of common stock Expected life of the options 3.73 years 3.69 years 3.69 years
Schedule of Share-based Compensation, Stock Options, Activity [Table Text Block]	Options Weighted Average Exercise Price Weighted Average Remaining Contractual Term Aggregate Intrinsic Value (000s) (000s) Outstanding at September 30, 2014 $ 4 years Granted $ Exercised ) $ Forfeited ) $ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Outstanding at September 30, 2015 $ 4 years $ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Exercisable at September 30, 2015 $ 3 years $ Expected to vest after September 30, 2015 $ 5 years $
Schedule of Nonvested Share Activity Table Text Block	Options Weighted Average Grant Date Fair Value (000s) Nonvested at September 30, 2014 $ Granted $ Vested ) $ Forfeited ) $ ​ ​ ​ ​ ​ ​ ​ ​ Nonvested at September 30, 2015 $ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​
Schedule of Share-based Compensation, Restricted Stock and Restricted Stock Units Activity [Table Text Block]	Restricted Shares Weighted Average Grant Date Fair Value (000s) Nonvested at September 30, 2014 $ Granted $ Vested ) $ Forfeited ) $ ​ ​ ​ ​ ​ ​ ​ ​ Nonvested at September 30, 2015 $ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​
Schedule of Nonvested Performance-based Units Activity Table Text Block	Performance Stock Units Weighted Average Grant Date Fair Value (000s) Nonvested at September 30, 2014 $ Granted $ Vested ) $ ​ ​ ​ ​ ​ ​ ​ ​ Nonvested at September 30, 2015 $ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​

Employee Severance, Litigation

Employee Severance, Litigation and Other (Tables)	12 Months Ended
	Sep. 30, 2015
Restructuring and Related Activities [Abstract]
Schedule Of Restructuring And Related Costs Text Block	The following table illustrates the charges incurred by the Company relating to employee severance, litigation and other for the three fiscal years ended September 30, 2015 (in thousands): 2015 2014 2013 Employee severance and other $ $ $ Deal-related transaction costs ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Total employee severance, litigation and other $ $ $ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​

Business Segment Information (T

Business Segment Information (Tables)	12 Months Ended
	Sep. 30, 2015
Business Segment Information [Abstract]
Reconciliation of revenue from segments to consolidated	The following tables illustrate reportable segment information for the periods indicated (in thousands): Revenue Fiscal year ended September 30, 2015 2014 2013 Pharmaceutical Distribution $ $ $ Other Intersegment eliminations ) ) ) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Revenue $ $ $ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​
Reconciliation segment operating income, depreciation & amortization, and capital expenditures from segments to consolidated	Segment Operating Income Fiscal year ended September 30, 2015 2014 2013 Pharmaceutical Distribution $ $ $ Other ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Total segment operating income $ $ $ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Depreciation & Amortization Fiscal year ended September 30, 2015 2014 2013 Pharmaceutical Distribution $ $ $ Other Acquisition-related intangibles amortization ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Total depreciation and amortization $ $ $ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Capital Expenditures Fiscal year ended September 30, 2015 2014 2013 Pharmaceutical Distribution $ $ $ Other ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Total capital expenditures $ $ $ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​
Reconciliation of total segment operating income to income from continuing operations before income taxes	The following table reconciles total segment operating income to income from continuing operations before income taxes (in thousands): Income From Continuing Operations Before Income Taxes Fiscal year ended September 30, 2015 2014 2013 Total segment operating income $ $ $ Gains on antitrust litigation settlements LIFO expense ) ) ) Acquisition-related intangibles amortization ) ) ) Warrant expense ) ) ) Employee severance, litigation and other ) ) ) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Operating income Other loss (income) ) Impairment charge on equity investment — — Interest expense, net Loss on early retirement of debt — — ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Income from continuing operations before income taxes $ $ $ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​
Reconciliation of assets from segment to consolidated	Assets At September 30, 2015 2014 Pharmaceutical Distribution $ $ Other ​ ​ ​ ​ ​ ​ ​ ​ Total assets $ $ ​ ​ ​ ​ ​ ​ ​ ​

Quarterly Financial Informati40

Quarterly Financial Information (Unaudited) (Tables)	12 Months Ended
	Sep. 30, 2015
Quarterly Financial Data [Abstract]
Schedule of Quarterly Financial Information [Table Text Block]	Fiscal Year Ended September 30, 2015 First Quarter Second Quarter Third Quarter Fourth Quarter Fiscal Year (In thousands, except per share amounts) Revenue $ $ $ $ $ Gross profit(a) $ $ $ $ $ Distribution, selling and administrative expenses, depreciation, and amortization Warrant expense ) ) Employee severance, litigation and other ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Operating (loss) income $ ) $ ) $ $ $ Net (loss) income $ ) $ ) $ $ $ ) Earnings per share operations: Basic $ ) $ ) $ $ $ ) Diluted $ ) $ ) $ $ $ ) (a) The second, third and fourth quarters of fiscal 2015 include gains of $21.5 million, $43.6 million, and $0.4 million, respectively, from antitrust litigation settlements. The first, second, third, and fourth quarters of fiscal 2015 include LIFO charges of $144.0 million, $151.1 million, $158.7 million, and $88.9 million, respectively. Fiscal Year Ended September 30, 2014 First Quarter Second Quarter Third Quarter Fourth Quarter Fiscal Year (In thousands, except per share amounts) Revenue $ $ $ $ $ Gross profit(a) $ $ $ $ $ Distribution, selling and administrative expenses, depreciation and amortization Warrant expense Employee severance, litigation and other ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Operating income $ $ $ $ $ Income (loss) from continuing operations $ $ $ ) $ $ Loss from discontinued operations, net of tax(b) ) — — — ) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Net income (loss) $ $ $ ) $ $ Earnings per share from continuing operations: Basic $ $ $ ) $ $ Diluted $ $ $ ) $ $ Earnings per share: Basic $ $ $ ) $ $ Diluted $ $ $ ) $ $ (a) The first, second, and third quarters of fiscal 2014 include gains of $21.0 million, $0.8 million, and $2.5 million, respectively, from antitrust litigation settlements. The first, second, third, and fourth quarters of fiscal 2014 include LIFO charges of $57.6 million, $102.8 million, $133.2 million, and $54.4 million, respectively. (b) Includes the impact of a final purchase price working capital adjustment related to the divestiture of ABCC (see Note 4).

Summary of Significant Accoun41

Summary of Significant Accounting Policies (Details)	12 Months Ended
	Sep. 30, 2015
Walgreens Boots Alliance, Inc [Member]
Concentration Risk [Line Items]
Trade Receivable Due From Single Customer As Percentage of Accounts Receivable	40.00%
Customer Revenue as Percentage of Total Revenue	30.00%
Express Scripts Inc [Member]
Concentration Risk [Line Items]
Trade Receivable Due From Single Customer As Percentage of Accounts Receivable	10.00%
Customer Revenue as Percentage of Total Revenue	16.00%

Summary of Significant Accoun42

Summary of Significant Accounting Policies (Details 2) CAD in Millions	Sep. 30, 2015CADcontract
Summary of Significant Accounting Policies [Abstract]
Derivative, Number of Instruments Held	1
Discontinued Operations Note Due from Buyer | CAD	CAD 46.9

Summary of Significant Accoun43

Summary of Significant Accounting Policies (Details 3) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2013
Equity Method Investment, Financial Statement, Reported Amounts [Abstract]
Impairment charge	$ 30,622	$ 0	$ 0
Profarma [Member]
Equity Method Investment, Financial Statement, Reported Amounts [Abstract]
Impairment charge	$ 30,600

Summary of Significant Accoun44

Summary of Significant Accounting Policies (Details 4) - USD ($) $ in Millions	Sep. 30, 2015	Sep. 30, 2014
Available-for-sale Securities [Abstract]
Available-for-sale securities	$ 86.2	$ 0
Prepaid Expenses and Other Current Assets [Member]
Available-for-sale Securities [Abstract]
Available-for-sale securities	50.8
Other Noncurrent Assets [Member]
Available-for-sale Securities [Abstract]
Available-for-sale securities	$ 35.4

Summary of Significant Accoun45

Summary of Significant Accounting Policies (Details 5) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2013
Summary of Significant Accounting Policies [Abstract]
Percentage of LIFO Inventory	80.00%				84.00%				80.00%	84.00%
Excess of Replacement or Current Costs over Stated LIFO Value	$ 1,424,600				$ 881,800				$ 1,424,600	$ 881,800
Inventory, LIFO Reserve, Period Charge	88,900	$ 158,700	$ 151,100	$ 144,000	54,400	$ 133,200	$ 102,800	$ 57,600	542,807	348,063	$ 277,001
Accrual for Estimated Customer Sales Returns	$ 841,300				$ 932,600				841,300	932,600
Excess tax benefits, Exercise of stock options									88,116	46,341	41,222
Shipping, Handling and Transportation Costs									$ 419,200	$ 348,300	$ 267,300

Summary of Significant Accoun46

Summary of Significant Accounting Policies (Details 6) - USD ($) $ in Millions	Sep. 30, 2015	Mar. 31, 2013
Summary of Significant Accounting Policies [Abstract]
Full Value of Warrants	$ 1,917.9	$ 242.4

Acquisition (Details)

Acquisition (Details) - USD ($) $ in Thousands

Feb. 24, 2015

Sep. 30, 2015

Jun. 30, 2015

Mar. 31, 2015

Dec. 31, 2014

Sep. 30, 2014

Jun. 30, 2014

Mar. 31, 2014

Dec. 31, 2013

Sep. 30, 2015

Sep. 30, 2014

Sep. 30, 2013

Business Acquisition [Line Items]

Revenue

$ 35,470,378

$ 34,233,556

$ 32,669,267

$ 33,588,602

$ 31,588,708

$ 30,348,154

$ 28,455,903

$ 29,176,362

$ 135,961,803

$ 119,569,127

$ 87,959,167

Goodwill

$ 4,130,825

$ 2,948,502

4,130,825

$ 2,948,502

$ 2,944,970

MWI Veterinary Supply, Inc. [Member]

Business Acquisition [Line Items]

Purchase price

$ 2,600,000

Goodwill

1,200,000

Accounts receivable

346,900

Inventory

440,000

Accounts payable

327,100

Deferred tax liability

570,700

Estimated fair value of the intangible assets acquired, finite-lived

1,500,000

MWI Veterinary Supply, Inc. [Member] | Trade Names [Member]

Business Acquisition [Line Items]

Estimated fair value of the intangible assets acquired, indefinite-lived

344,000

MWI Veterinary Supply, Inc. [Member] | Customer Relationships [Member]

Business Acquisition [Line Items]

Estimated fair value of the intangible assets acquired, finite-lived

$ 1,100,000

Remaining estimated useful lives

20 years

MWI Veterinary Supply, Inc. [Member] | Computer Software, Intangible Asset [Member]

Business Acquisition [Line Items]

Estimated fair value of the intangible assets acquired, finite-lived

$ 11,000

Remaining estimated useful lives

8 years

MWI Veterinary Supply, Inc. [Member]

Business Acquisition [Line Items]

Revenue

$ 3,000,000

Equity Method Investments (Deta

Equity Method Investments (Details) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2013	Jun. 30, 2014
Schedule of Equity Method Investments [Line Items]
Cost of equity investments	$ 0	$ 117,794	$ 0
Impairment charge	30,622	$ 0	$ 0
Equity method investments	$ 30,500
Profarma [Member]
Schedule of Equity Method Investments [Line Items]
Equity Method Investment Ownership Percentage	19.90%			19.90%
Impairment charge	$ 30,600
Specialty Joint Venture [Member]
Schedule of Equity Method Investments [Line Items]
Equity Method Investment Ownership Percentage				50.00%

Discontinued Operations (Detail

Discontinued Operations (Details) $ in Thousands, CAD in Millions	12 Months Ended
	Sep. 30, 2015USD ($)	Sep. 30, 2014USD ($)	Sep. 30, 2013USD ($)	Sep. 30, 2015CAD	Sep. 30, 2013CAD
Income Statement Balance Sheet and Additional Disclosures by Disposal Groups Including Discontinued Operations [Line Items]
Discontinued Operations Note Due from Buyer | CAD				CAD 46.9
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Reclassification Adjustment Realized Upon Sale or Liquidation, Net of Tax			$ 9,300
Disposal Group, Including Discontinued Operation, Income Statement Disclosures [Abstract]
Revenue	$ 0	$ 0	1,181,231
Loss before income taxes	$ 0	$ (7,546)	(50,090)
AmerisourceBergen Canada Corporation [Member]
Income Statement Balance Sheet and Additional Disclosures by Disposal Groups Including Discontinued Operations [Line Items]
Discontinued Operation Gain Loss From Disposal Of Discontinued Operation Before Income Tax			(143,700)
Goodwill Impairment Loss			26,900
Proceeds from sales of business			$ 67,900
Discontinued Operations Note Due from Buyer | CAD					CAD 50
Discontinued Operations Annual Interest Rate on Note Due from Buyer					3.00%
Discontinued opertation, note due from buyer, term			7 years
Anderson Brecon [Member]
Income Statement Balance Sheet and Additional Disclosures by Disposal Groups Including Discontinued Operations [Line Items]
Discontinued Operation Gain Loss From Disposal Of Discontinued Operation Before Income Tax			$ 114,100
Proceeds from sales of business			$ 306,500

Income Taxes (Details)

Income Taxes (Details) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2013
Income Taxes [Abstract]
Income (Loss) from Continuing Operations before Income Taxes, Domestic	$ 60,730	$ 591,909	$ 793,137
Income (Loss) from Continuing Operations before Income Taxes, Foreign	213,419	81,519	31,321
Income from continuing operations before income taxes	$ 274,149	$ 673,428	$ 824,458

Income Taxes (Details 2)

Income Taxes (Details 2) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2013	Mar. 31, 2013
Current Income Tax Expense (Benefit), Continuing Operations [Abstract]
Current Federal Tax Expense (Benefit)	$ 310,847	$ 297,052	$ 259,457
Current State and Local Tax Expense (Benefit)	46,240	37,301	37,602
Current Foreign Tax Expense (Benefit)	29,216	15,733	8,391
Current Income Tax Expense Benefit	386,303	350,086	305,450
Deferred Income Tax Expense (Benefit), Continuing Operations [Abstract]
Deferred Federal Income Tax Expense (Benefit)	2,923	16,576	29,189
Deferred State and Local Income Tax Expense (Benefit)	18,468	22,842	(3,375)
Deferred Foreign Income Tax Expense (Benefit)	1,342	(106)	(241)
Provision for deferred income taxes	22,733	39,312	25,573
Income taxes	$ 409,036	$ 389,398	$ 331,023
Effective Income Tax Rate Reconciliation, Percent [Abstract]
Effective Income Tax Rate Reconciliation At Federal Statutory Income Tax Rate	35.00%	35.00%	35.00%
Effective Income Tax Rate Reconciliation State And Local Income Taxes	10.20%	4.10%	3.00%
Effective Income Tax Rate Reconciliation Foreign Income Tax Rate Differential	(20.00%)	(1.90%)	(0.30%)
Effective Income Tax Rate Reconciliation Nondeductible Expense Other	107.70%	18.40%	2.30%
Effective Income Tax Rate Reconciliation Change in Deferred Tax Assets Valuation Allowance	9.10%	1.70%	0.00%
Effective Income Tax Rate Reconciliation Other Adjustments	7.20%	0.50%	0.20%
Effective Income Tax Rate Continuing Operations	149.20%	57.80%	40.20%
Full Value of Warrants	$ 1,917,900			$ 242,400

Income Taxes (Details 3)

Income Taxes (Details 3) - USD ($) $ in Thousands	Sep. 30, 2015	Sep. 30, 2014
Components of Deferred Tax Assets and Liabilities [Abstract]
Merchandise inventories	$ 1,207,356	$ 1,146,695
Property and equipment	116,537	111,525
Goodwill and other intangible assets	865,316	273,147
Other	1,107	988
Gross deferred tax liabilities	2,190,316	1,532,355
Deferred Tax Liabilities, Gross [Abstract]
Net operating loss and tax credit carryforwards	(73,691)	(59,404)
Capital loss carryforwards	(65,811)	(61,886)
Allowance for doubtful accounts	(30,549)	(33,915)
Accrued expenses	(24,248)	(23,857)
Employee and retiree benefits	(6,165)	(6,534)
Stock options	(41,233)	(35,845)
Warrants	(59,917)	(25,426)
Other	(66,582)	(54,213)
Deferred Tax Assets, Gross [Abstract]
Gross deferred tax assets	(368,196)	(301,080)
Valuation allowance for deferred tax assets	132,085	105,393
Deferred tax assets, net of valuation allowance	(236,111)	(195,687)
Net deferred tax liabilities	$ 1,954,205	$ 1,336,668

Income Taxes (Details 4)

Income Taxes (Details 4) $ in Millions	12 Months Ended
	Sep. 30, 2015USD ($)
Domestic Tax Authority [Member]
Operating Loss Carryforwards [Line Items]
Net operating loss carryforwards	$ 6.2
State and Local Jurisdiction [Member]
Operating Loss Carryforwards [Line Items]
Net operating loss carryforwards	75.9
Potential Tax Benefits That Would Be Recorded As Paid In Capital	13.2
Foreign Tax Authority [Member]
Operating Loss Carryforwards [Line Items]
Net operating loss carryforwards	$ 15.4
Minimum [Member] | Domestic Tax Authority [Member]
Operating Loss Carryforwards [Line Items]
Net operating loss carryforwards, term	3 years
Minimum [Member] | State and Local Jurisdiction [Member]
Operating Loss Carryforwards [Line Items]
Net operating loss carryforwards, term	1 year
Maximum [Member] | Domestic Tax Authority [Member]
Operating Loss Carryforwards [Line Items]
Net operating loss carryforwards, term	16 years
Maximum [Member] | State and Local Jurisdiction [Member]
Operating Loss Carryforwards [Line Items]
Net operating loss carryforwards, term	20 years

Income Taxes (Details 5)

Income Taxes (Details 5) $ in Millions	12 Months Ended
	Sep. 30, 2015USD ($)
State and Local Jurisdiction [Member]
Tax Credit Carryforward [Line Items]
Tax credit carryforwards	$ 2.2
Foreign Tax Authority [Member]
Tax Credit Carryforward [Line Items]
Tax credit carryforwards	5.8
Capital Loss Carryforward [Member]
Tax Credit Carryforward [Line Items]
Tax credit carryforwards	65.8
Alternative Minimum Tax [Member]
Tax Credit Carryforward [Line Items]
Tax credit carryforwards	$ 2.1
Minimum [Member] | Foreign Tax Authority [Member]
Tax Credit Carryforward [Line Items]
Tax credit carryforwards, term	3 years
Minimum [Member] | Capital Loss Carryforward [Member]
Tax Credit Carryforward [Line Items]
Tax credit carryforwards, term	1 year
Maximum [Member] | Foreign Tax Authority [Member]
Tax Credit Carryforward [Line Items]
Tax credit carryforwards, term	9 years
Maximum [Member] | Capital Loss Carryforward [Member]
Tax Credit Carryforward [Line Items]
Tax credit carryforwards, term	5 years

Income Taxes (Details 6)

Income Taxes (Details 6) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2013
Income Taxes [Abstract]
Valuation Allowance, Deferred Tax Asset, Increase (Decrease), Amount	$ 26,700	$ (222,200)
Excess tax benefits, Exercise of stock options	88,116	46,341	$ 41,222
Income Taxes Paid, Net	299,600	197,000	$ 313,700
Unrecognized Tax Benefits Including Federal Benefit	52,800	50,600
Unrecognized Tax Benefits That Would Impact Effective Tax Rate	37,200	35,800
Unrecognized Tax Benefits Income Tax Penalties And Interest Accrued	$ 8,100	$ 7,700

Income Taxes (Details 7)

Income Taxes (Details 7) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2013
Unrecognized Tax Benefits Schedule [Abstract]
Unrecognized Tax Benefits Beginning of Period	$ 42,908	$ 46,267	$ 36,990
Unrecognized tax benefits, increase resulting from current period tax positions	3,616	6,127	5,272
Unrecognized tax benefits increases resulting from prior period tax positions		1,249	2,825
Unrecognized tax benefits increase from acquisition			2,500
Unrecognized tax benefits decreases resulting from prior period tax positions	(871)	(4,167)
Unrecognized tax benefits decreases resulting from settlements with taxing authorities	(33)	(4,788)	(519)
Unrecognized tax benefits reductions resulting from lapse of applicable statute of limitations	(898)	(1,780)	(801)
Unrecognized Tax Benefits End of Period	44,722	$ 42,908	$ 46,267
Significant Change In Unrecognized Tax Benefits Is Reasonably Possible Amount Of Unrecorded Benefit	9,500
Undistributed earnings of foreign subsidiaries	$ 412,700

Goodwill and Other Intangible57

Goodwill and Other Intangible Assets (Details) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2015	Sep. 30, 2014
Goodwill [Roll Forward]
Goodwill	$ 2,948,502	$ 2,944,970
Goodwill recognized in connection with acquisition	1,192,684	5,665
Goodwill disposed in connection with divestitures	(6,231)
Foreign currency translation	(4,130)	(2,133)
Goodwill	4,130,825	2,948,502
Pharmaceutical Distribution [Member]
Goodwill [Roll Forward]
Goodwill	2,400,926	2,400,926
Goodwill recognized in connection with acquisition	21,485	0
Goodwill disposed in connection with divestitures	(3,605)
Foreign currency translation	0	0
Goodwill	2,418,806	2,400,926
Other Segments [Member]
Goodwill [Roll Forward]
Goodwill	547,576	544,044
Goodwill recognized in connection with acquisition	1,171,199	5,665
Goodwill disposed in connection with divestitures	(2,626)
Foreign currency translation	(4,130)	(2,133)
Goodwill	$ 1,712,019	$ 547,576

Goodwill and Other Intangible58

Goodwill and Other Intangible Assets (Details 2) - USD ($) $ in Thousands	Sep. 30, 2015	Sep. 30, 2014
Trade Names [Member]
Indefinite-Lived Intangible Assets (Excluding Goodwill) [Abstract]
Indefinite-lived intangibles	$ 684,966	$ 343,707

Goodwill and Other Intangible59

Goodwill and Other Intangible Assets (Details 3) - USD ($) $ in Thousands	Sep. 30, 2015	Sep. 30, 2014
Finite-lived intangibles
Accumulated amortization	$ (194,318)	$ (149,787)
Customer Relationships [Member]
Finite-lived intangibles
Gross carrying amount	1,421,230	268,208
Accumulated amortization	(146,227)	(98,412)
Net carrying amount	1,275,003	169,796
Other Intangible Assets [Member]
Finite-lived intangibles
Gross carrying amount	81,241	71,114
Accumulated amortization	(48,091)	(51,375)
Net carrying amount	$ 33,150	$ 19,739

Goodwill and Other Intangible60

Goodwill and Other Intangible Assets (Details 4) - USD ($) $ in Thousands	Sep. 30, 2015	Sep. 30, 2014
Intangible Assets, Net (Excluding Goodwill) [Abstract]
Gross carrying amount	$ 2,187,437	$ 683,029
Accumulated amortization	(194,318)	(149,787)
Net carrying amount	$ 1,993,119	$ 533,242

Goodwill and Other Intangible61

Goodwill and Other Intangible Assets (Details 5) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2013
Goodwill and Other Intangible Assets [Abstract]
Amortization expense	$ 56,491	$ 25,962	$ 27,139

Goodwill and Other Intangible62

Goodwill and Other Intangible Assets (Details 6) $ in Millions	Sep. 30, 2015USD ($)
Amortization expense, fiscal year maturity
2,016	$ 82.1
2,017	79
2,018	76.6
2,019	74.9
2,020	72.6
Thereafter	$ 923

Debt (Details)

Debt (Details) £ in Millions	Sep. 30, 2015GBP (£)	Feb. 24, 2015USD ($)	Nov. 30, 2015	Feb. 28, 2015USD ($)	Sep. 30, 2015USD ($)	Sep. 30, 2014USD ($)	Sep. 30, 2013USD ($)	Sep. 30, 2015USD ($)
Debt Instrument [Line Items]
Long term debt						$ 1,995,632,000		$ 3,493,048,000
Repayments of term loan					$ 500,000,000	531,525,000	$ 0
Scheduled repayment in year two								600,000,000
Scheduled repayment in year Four								900,000,000
Scheduled repayment in year five and thereafter								2,000,000,000
Interest paid					91,500,000	62,900,000	68,500,000
Amortization of financing fees and accretion of original issue discounts					$ 5,200,000	3,900,000	$ 4,200,000
MWI Veterinary Supply, Inc. [Member]
Debt Instrument [Line Items]
Purchase price		$ 2,600,000,000
Multi Currency Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Maturity date			November 2,020		August 2,019
Long term debt						0		0
Maximum borrowing capacity								1,400,000,000
Interest rate description					69 basis points to 110 basis points over LIBOR/EURIBOR/Bankers Acceptance Stamping Fee
Covenant terms					The Multi-Currency Revolving Credit Facility contains covenants, including compliance with a financial leverage ratio test, as well as others that impose limitations on, among other things, indebtedness of excluded subsidiaries and asset sales, with which the Company was compliant as of September 30, 2015.
Canadian prime rate					the Canadian prime rate or the CDOR rate
Debt Instrument Facility Fee Rate Effective Percentage Rate Range Minimum					0.06%
Debt Instrument Facility Fee Rate Effective Percentage Rate Range Maximum					0.15%
Commitment fee percentage					0.10%
Multi Currency Revolving Credit Facility [Member] | LIBOR / EURIBOR / Bankers Acceptance Stamping Fee [Member]
Debt Instrument [Line Items]
Variable rate spread (as a percent)					0.90%
Multi Currency Revolving Credit Facility [Member] | LIBOR / EURIBOR / Bankers Acceptance Stamping Fee [Member] | Minimum [Member]
Debt Instrument [Line Items]
Variable rate spread (as a percent)					0.69%
Multi Currency Revolving Credit Facility [Member] | LIBOR / EURIBOR / Bankers Acceptance Stamping Fee [Member] | Maximum [Member]
Debt Instrument [Line Items]
Variable rate spread (as a percent)					1.10%
Receivables Securitization Facility [Member]
Debt Instrument [Line Items]
Maturity date			November 2,018		December 2,017
Long term debt						0		0
Maximum borrowing capacity								950,000,000
Interest rate description					prevailing market rates for short-term commercial paper or LIBOR plus a program fee.
Covenant terms					The Receivables Securitization Facility contains similar covenants to the Multi-Currency Revolving Credit Facility, with which the Company was compliant as of September 30, 2015.
Ability to Increase Debt Commitment Under Accordion Feature in December and March Quarters					$ 250,000,000
Revolving Credit Note [Member]
Debt Instrument [Line Items]
Long term debt						0		0
Maximum borrowing capacity								75,000,000
Overdraft Facility [Member]
Debt Instrument [Line Items]
Long term debt						0		0
Maximum borrowing capacity | £	£ 20
Term Loan [Member]
Debt Instrument [Line Items]
Long term debt						0		500,000,000
Maximum borrowing capacity				$ 1,000,000,000
Quarterly principal payments 1-9				1.25%
Quarterly principal payments 10-20				2.50%
Repayments of term loan					500,000,000
Scheduled principal payment					$ 25,000,000
Term Loan [Member] | London Interbank Offered Rate LIBOR [Member]
Debt Instrument [Line Items]
Variable rate spread (as a percent)	1.00%
Term Loan [Member] | London Interbank Offered Rate LIBOR [Member] | Minimum [Member]
Debt Instrument [Line Items]
Variable rate spread (as a percent)				0.75%
Term Loan [Member] | London Interbank Offered Rate LIBOR [Member] | Maximum [Member]
Debt Instrument [Line Items]
Variable rate spread (as a percent)				1.25%
Term Loan [Member] | Base Rate [Member] | Minimum [Member]
Debt Instrument [Line Items]
Variable rate spread (as a percent)				0.00%
Term Loan [Member] | Base Rate [Member] | Maximum [Member]
Debt Instrument [Line Items]
Variable rate spread (as a percent)				0.25%
Senior Notes Due 2015 [Member]
Debt Instrument [Line Items]
Face amount						$ 500,000,000
Stated percentage						5.875%
Premiums and other costs						$ 31,500,000
Senior Notes Due 2017 [Member]
Debt Instrument [Line Items]
Face amount								$ 600,000,000
Stated percentage	1.15%							1.15%
Maturity date					May 15, 2017
Long term debt						599,379,000		$ 599,658,000
Debt instrument issuance discount percentage					99.892%
Effective Percentage	1.187%							1.187%
Senior Notes Due 2019 [Member]
Debt Instrument [Line Items]
Face amount								$ 400,000,000
Stated percentage	4.875%							4.875%
Maturity date					November 15, 2019
Long term debt						398,122,000		$ 398,456,000
Debt instrument issuance discount percentage					99.20%
Effective Percentage	4.98%							4.98%
Senior Notes Due 2021 [Member]
Debt Instrument [Line Items]
Face amount								$ 500,000,000
Stated percentage	3.50%							3.50%
Maturity date					November 15, 2021
Long term debt						499,497,000		$ 499,568,000
Debt instrument issuance discount percentage					99.858%
Effective Percentage	3.52%							3.52%
Senior Notes Due 2024 [Member]
Debt Instrument [Line Items]
Face amount								$ 500,000,000
Stated percentage	3.40%							3.40%
Maturity date					May 15, 2024
Long term debt						498,634,000		$ 498,777,000
Debt instrument issuance discount percentage					99.715%
Effective Percentage	3.434%							3.434%
Senior Notes Due 2025 [Member]
Debt Instrument [Line Items]
Face amount				$ 500,000,000
Stated percentage				3.25%
Maturity date				March 1, 2025
Long term debt						0		$ 497,503,000
Debt instrument issuance discount percentage				99.47%
Effective Percentage				3.31%
Senior Notes Due 2045 [Member]
Debt Instrument [Line Items]
Face amount				$ 500,000,000
Stated percentage				4.25%
Maturity date				March 1, 2045
Long term debt						$ 0		499,086,000
Debt instrument issuance discount percentage				99.81%
Effective Percentage				4.26%
Commercial Paper [Member]
Debt Instrument [Line Items]
Short-term borrowings								0
Maximum borrowing capacity								$ 1,400,000,000
Terms of short term debt					The Company has a commercial paper program whereby it may from time to time issue short-term promissory notes in an aggregate amount of up to $1.4 billion at any one time. Amounts available under the program may be borrowed, repaid, and re-borrowed from time to time. The maturities on the notes will vary, but may not exceed 365 days from the date of issuance. The notes will bear interest rates, if interest bearing, or will be sold at a discount from their face amounts. The commercial paper program does not increase the Company's borrowing capacity as it is fully backed by the Company's Multi-Currency Revolving Credit Facility. There were no borrowings outstanding under the commercial paper program at September 30, 2015.

Stockholders' Equity and Earn64

Stockholders' Equity and Earnings per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	Sep. 30, 2015	Sep. 30, 2014
Stockholders' Equity and Earnings per Share [Abstract]
Common stock, shares authorized	600,000,000	600,000,000
Common stock, par value	$ 0.01	$ 0.01
Preferred Stock, Shares Authorized	10,000,000
Preferred Stock, Par or Stated Value Per Share	$ 0.01
Accumulated Other Comprehensive Income Loss Defined Benefit Pension And Other Postretirement Plans Net Of Tax	$ (36,819)	$ (32,212)
Accumulated Other Comprehensive Income Loss Foreign Currency Translation Adjustment Net Of Tax	(99,393)	(19,388)
Accumulated Other Comprehensive Income Loss Other Net of Tax	(121)	(446)
Accumulated other comprehensive loss	$ (136,333)	$ (52,046)

Stockholders' Equity and Earn65

Stockholders' Equity and Earnings per Share (Details 2) - USD ($) $ in Thousands, shares in Millions	1 Months Ended						12 Months Ended
	Mar. 31, 2015	Oct. 31, 2014	Dec. 31, 2012	Nov. 30, 2012	Oct. 31, 2012	Aug. 31, 2012	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2012	Apr. 30, 2015	May. 31, 2014	Aug. 31, 2013	May. 31, 2012
Treasury Stock Program [Line Items]
Call options purchased on common stock	6
Purchases of common stock							$ 1,823,106	$ 789,927	$ 473,864
Accelerated Share Repurchase Program Authorized Amount				$ 250,000		$ 650,000
Accelerated Stock Repurchase Program Initial Delivery of Shares				6.2		16.8
Accelerated Share Repurchase Program Initial Funding Allocated to Share Purchases				$ 248,500		$ 647,200
Accelerated Share Repurchase Program Initial Funding Allocated to Prepaid Dividends				1,300		2,000
Accelerated Share Repurchase Program Initial Funding Allocated to Fees				$ 200		$ 800
Accelerated Share Repurchase Program Incremental Shares Received Upon Settlement					$ 100
Settlement of accelerated stock repurchase agreement			$ 10,300						$ 10,312
May 2012 Share Repurchase Program [Member]
Treasury Stock Program [Line Items]
Stock Repurchase Program Authorized Amount														$ 750,000
Treasury Stock, Shares, Acquired									0.6	0.2
Purchases of common stock									$ 25,700	$ 5,900
Accelerated Stock Repurchase Program Initial Delivery of Shares				1.7
Accelerated Share Repurchase Program Initial Funding Allocated to Share Purchases				$ 71,200
November 2012 Share Repurchase Program [Member]
Treasury Stock Program [Line Items]
Stock Repurchase Program Authorized Amount				$ 750,000
Treasury Stock, Shares, Acquired								5.5	3.6
Purchases of common stock								$ 363,000	$ 199,400
Accelerated Stock Repurchase Program Initial Delivery of Shares				4.5
Accelerated Share Repurchase Program Initial Funding Allocated to Share Purchases				$ 187,600
August 2013 Share Repurchase Program [Member]
Treasury Stock Program [Line Items]
Stock Repurchase Program Authorized Amount													$ 750,000
Treasury Stock, Shares, Acquired							3.3	2.4
Purchases of common stock							$ 300,800	$ 174,700
Treasury Stock Value Acquired Cost Method Settlements		$ 18,000
Treasury Stock Purchase Program Availability								$ 274,500
May 2014 Share Repurchase Program [Member]
Treasury Stock Program [Line Items]
Stock Repurchase Program Authorized Amount												$ 650,000
Treasury Stock, Shares, Acquired							4.3	3.4
Call options purchased on common stock							1.6
Value of call options purchased							$ 151,200
Purchases of common stock							$ 398,000	$ 252,000
Treasury Stock Value Acquired Cost Method Settlements		$ 18,000
April 2015 Share Repurchase Program [Member]
Treasury Stock Program [Line Items]
Stock Repurchase Program Authorized Amount											$ 1,000,000
Treasury Stock, Shares, Acquired							10
Call options purchased on common stock							2.9
Value of call options purchased							$ 276,300
Purchases of common stock							1,000,000
September 2015 Share Repurchase Program [Member]
Treasury Stock Program [Line Items]
Stock Repurchase Program Authorized Amount							$ 2,400,000
Treasury Stock, Shares, Acquired							1.2
Purchases of common stock							$ 124,100
Treasury Stock Purchase Program Availability							$ 2,275,900

Stockholders' Equity and Earn66

Stockholders' Equity and Earnings per Share (Details 3)	1 Months Ended
	Mar. 31, 2013$ / sharesshares
Class of Warrant or Right [Line Items]
Shares to which framework agreement allows open market purchases.	19,859,795
Percentage of Common Stock Purchases in Open Market Granted under Framework Agreement	7.00%
Walgreens Warrant 1 [Member]
Class of Warrant or Right [Line Items]
Class of Warrant or Right, Date from which Warrants or Rights are Exercisable	Mar. 1, 2016
Class of Warrant or Right, Number of Securities Called by Warrants or Rights	11,348,456
Class of Warrant or Right, Exercise Price of Warrants or Rights 1 | $ / shares	$ 51.50
Walgreens Warrant 2 [Member]
Class of Warrant or Right [Line Items]
Class of Warrant or Right, Date from which Warrants or Rights are Exercisable	Mar. 1, 2017
Class of Warrant or Right, Number of Securities Called by Warrants or Rights	11,348,456
Class of Warrant or Right, Exercise Price of Warrants or Rights 1 | $ / shares	$ 52.50
Alliance Boots Warrant 1 [Member]
Class of Warrant or Right [Line Items]
Class of Warrant or Right, Date from which Warrants or Rights are Exercisable	Mar. 1, 2016
Class of Warrant or Right, Number of Securities Called by Warrants or Rights	11,348,456
Class of Warrant or Right, Exercise Price of Warrants or Rights 1 | $ / shares	$ 51.50
Alliance Boots Warrant 2 [Member]
Class of Warrant or Right [Line Items]
Class of Warrant or Right, Date from which Warrants or Rights are Exercisable	Mar. 1, 2017
Class of Warrant or Right, Number of Securities Called by Warrants or Rights	11,348,456
Class of Warrant or Right, Exercise Price of Warrants or Rights 1 | $ / shares	$ 52.50

Stockholders' Equity and Earn67

Stockholders' Equity and Earnings per Share (Details 4) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	1 Months Ended		12 Months Ended
	Jan. 31, 2015	Jan. 31, 2014	Sep. 30, 2015	Mar. 31, 2013
Forward Contract Indexed to Issuer's Equity [Line Items]
Fair Value per Share of First Tranche of Warrants			$ 43.03
Fair Value per Share of Second Tranche of Warrants			$ 41.47
Full Value of Warrants			$ 1,917.9	$ 242.4
Percentage of Warrant Dilution Intended to be Hedged with Contract			60.00%
Shares Covered Under Derivative Purchases		27.2
Derivative, Cost of Hedge	$ 100	$ 368.7
First Group of Tranches [Member]
Forward Contract Indexed to Issuer's Equity [Line Items]
Exercise price			$ 51.50
Second Group of Tranches [Member]
Forward Contract Indexed to Issuer's Equity [Line Items]
Exercise price			$ 52.50

Stockholders' Equity and Earn68

Stockholders' Equity and Earnings per Share (Details 5) - USD ($) $ in Millions	1 Months Ended	12 Months Ended
	Mar. 31, 2015	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2013
Stockholders' Equity and Earnings per Share [Abstract]
Basic		217,786	227,367	231,067
Incremental Common Shares Attributable To Share Based Payment Arrangements		0	4,787	4,278
Incremental Common Shares Attributable to Call Options and Warrants		0	3,251	0
Weighted Average Number of Shares Outstanding, Diluted, Total		217,786	235,405	235,345
Antidilutive Securities Excluded From Computation Of Earnings Per Share Amount		18,600,000	2,000,000	0
Call options purchased on common stock	6,000,000
Total premium	$ 80
Capped calls associated with the warrants exercisable in 2016 (as a percent)		56.00%
Capped calls associated with warrants exercisable in 2017 (as a percent)		50.00%
Exercisable warrants covered in 2016		100.00%
Exercisable warrants covered in 2017		89.00%

Pension and Other Benefit Pla69

Pension and Other Benefit Plans (Details) $ in Millions	3 Months Ended	12 Months Ended
	Dec. 31, 2015USD ($)	Sep. 30, 2015USD ($)employee	Sep. 30, 2014USD ($)	Sep. 30, 2013USD ($)
Pension and Other Postretirement Benefit Expense [Abstract]
Pension and Other Postretirement Benefit Expense		$ 26.4	$ 27.9	$ 22.1
Defined Benefit Plan, Settlements and Curtailments [Abstract]
Retirement Benefit Plans Net Actuarial Loss Included in Accumulated Other Comprehensive Income Gross		59.1
Retirement Benefit Plans Net Actuarial Loss Included in Accumulated Other Comprehensive Loss Net of Tax		$ 36.8
Defined Benefit Plan Number of Plan Participants | employee		3,200
Defined Benefit Plan Number of Active Employees | employee		500
Scenario, Forecast [Member]
Defined Benefit Plan, Settlements and Curtailments [Abstract]
Plan termination expense	$ 65

Pension and Other Benefit Pla70

Pension and Other Benefit Plans (Details 2) - Pension Plans Defined Benefit Member - USD ($) $ in Millions	12 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2013
Defined Benefit Plan Disclosure [Line Items]
Projected benefit obligation	$ 159.5	$ 161.7
Accumulated benefit obligation	159.5
Fair value of plan assets	$ 168.9	$ 175.4
Discount rate (as a percent)	4.12%	4.08%
Pension Plan Assets Money Market Funds	$ 60.5	$ 1.7
Pension Plan Assets Commingled Fixed Income Funds	108.4	173.7
Employer contributions	$ 0	$ 0	$ 0
Debt Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Actual asset allocations (as a percent)	64.00%	64.00%
Target asset allocations (as a percent)	99.00%	99.00%
Cash and Cash Equivalents [Member]
Defined Benefit Plan Disclosure [Line Items]
Actual asset allocations (as a percent)	36.00%	36.00%
Target asset allocations (as a percent)	1.00%	1.00%

Pension and Other Benefit Pla71

Pension and Other Benefit Plans (Details 3) - USD ($) $ in Millions	12 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2013
Defined Contribution Pension and Other Postretirement Plans Disclosure [Abstract]
Defined Contribution Plan, Employer Discretionary Contribution Amount	$ 0		$ 0
Deferred Compensation Arrangement with Individual, Annual Distributions	4.00%
Defined Contribution Plan Cost Recognized	$ 23.5	$ 22.5	$ 17.4
Employee Contribution, First Three Percent of Salary [Member]
Defined Contribution Pension and Other Postretirement Plans Disclosure [Abstract]
Defined Contribution Plan, Employer Matching Contribution, Percent of Match	100.00%
Defined Contribution Plan, Employer Matching Contribution, Percent of Employees' Gross Pay	3.00%
Employee Contribution, Additional Two Percent of Salary [Member]
Defined Contribution Pension and Other Postretirement Plans Disclosure [Abstract]
Defined Contribution Plan, Employer Matching Contribution, Percent of Match	50.00%
Defined Contribution Plan, Employer Matching Contribution, Percent of Employees' Gross Pay	2.00%
Minimum [Member]
Defined Contribution Pension and Other Postretirement Plans Disclosure [Abstract]
Defined Contribution Plan, Maximum Annual Contributions Per Employee	1.00%
Maximum [Member]
Defined Contribution Pension and Other Postretirement Plans Disclosure [Abstract]
Defined Contribution Plan, Maximum Annual Contributions Per Employee	25.00%

Pension and Other Benefit Pla72

Pension and Other Benefit Plans (Details 4) - USD ($) shares in Thousands, $ in Millions	12 Months Ended
	Sep. 30, 2015	Sep. 30, 2014
Deferred Compensation Arrangements [Abstract]
Deferred Compensation Arrangement with Individual, Shares Authorized for Issuance	2,960
Deferred Compensation Arrangement with Individual, Shares Issued	0
Deferred Compensation Arrangement with Individual, Recorded Liability	$ 18	$ 16.2

Share-Based Compensation (Detai

Share-Based Compensation (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	12 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2013
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share Based Compensation Arrangement By Share Based Payment Award Number of Shares Available for Grant Under AmerisourceBergen Equity Incentive Plan	24.8
Granted	$ 14.91	$ 11.22	$ 6.54
Risk-free interest rate	1.23%	0.89%	0.44%
Expected dividend yield	1.29%	1.37%	1.29%
Volatility of common stock	23.12%	23.91%	24.22%
Expected life of the options	3 years 8 months 23 days	3 years 8 months 9 days	3 years 8 months 9 days
Stock or Unit Option Plan Expense	$ 30.2	$ 21.5	$ 20.2
Employee Stock Option [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period (in years)	4 years
Expiration period	7 years
Expiration period, prior to 2008	10 years
Non Employee [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period (in years)	3 years
Expiration period	10 years

Share-Based Compensation (Det74

Share-Based Compensation (Details 2) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	12 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2013
Options (in shares)
Outstanding at September 30, 2014 (in shares)	13,120
Granted (in shares)	2,421
Exercised (in shares)	(3,522)
Forfeited (in shares)	(132)
Outstanding at September 30, 2015 (in shares)	11,887	13,120
Exercisable at September 30, 2015 (in shares)	5,502
Expected to vest after September 30, 2015 (in shares)	5,917
Weighted Average Exercise Price (per share)
Outstanding at September 30, 2014 (per share)	$ 40
Granted (per share)	90
Exercised (per share)	31
Forfeited (per share)	59
Outstanding at September 30, 2015 (per share)	53	$ 40
Exercisable at September 30, 2015 (per share)	37
Expected to vest after September 30, 2015 (per share)	$ 66
Weighted Average Remaining Contractual Term
Weighted Average Contractual Term Options Outstanding	4 years	4 years
Weighted Average Contractual Term Options Exercisable	3 years
Weighted Average Contractual Term Options Expected to Vest	5 years
Aggregate Intrinsic Value
Outstanding at September 30, 2015	$ 502,528
Exercisable at September 30, 2015	317,683
Expected to vest after September 30, 2015	171,292
Intrinsic value of stock option exercises	$ 240,200	$ 132,400	$ 131,800

Share-Based Compensation (Det75

Share-Based Compensation (Details 3) - USD ($) $ / shares in Units, shares in Thousands, $ in Millions	12 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2013
Nonvested Options
Nonvested at September 30, 2014	6,801
Granted (in shares)	2,421
Vested	(2,705)
Forfeited	(132)
Nonvested at September 30, 2015	6,385	6,801
Nonvested Options Weighted Average
Nonvested at September 30, 2014	$ 8
Granted	14.91	$ 11.22	$ 6.54
Vested	8
Forfeited	10
Nonvested at September 30, 2015	$ 11	$ 8
Total fair values of options vested	$ 20.7	$ 19.1	$ 17.4
Employee Service Share Based Compensation Nonvested Awards Total Compensation Cost Not Yet Recognized Stock Options	$ 41.5
Weighted Average Period of Unrecognized Option Compensation	2 years 1 month 6 days

Share-Based Compensation (Det76

Share-Based Compensation (Details 4) - USD ($) $ / shares in Units, shares in Thousands, $ in Millions	12 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2013
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Requisite service period	30 days
Restricted Stock Expense	$ 20.1	$ 14.7	$ 12.1
Restricted Shares
Nonvested at September 30, 2014	950
Granted	226
Vested	(290)
Forfeited	(18)
Nonvested at September 30, 2015	868	950
Weighted Average
Nonvested at September 30, 2014	$ 48
Granted	91
Vested	38
Forfeited	53
Nonvested at September 30, 2015	$ 63	$ 48
Total fair values of restricted shares vested	$ 10.9	$ 10.5	$ 9.7
Restricted Stock Compensation Not Yet Recognized	$ 18.6
Weighted Average Period of Unrecognized Restricted Stock Compensation	1 year
Restricted Stock And Restricted Stock Units R S U [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period (in years)	3 years
Requisite service period	3 years

Share-Based Compensation (Det77

Share-Based Compensation (Details 5) - USD ($) $ / shares in Units, $ in Millions	12 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2013
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Performance share expense	$ 10.6	$ 6.8	$ 3.7
Performance Stock Units
Nonvested at September 30, 2014	220,000
Granted	86,000
Vested	(126,000)
Nonvested at September 30, 2015	180,000	220,000
Nonvested Performance Stock Units, Weighted Average
Nonvested at September 30, 2014	$ 52
Granted	89
Vested	40
Nonvested at September 30, 2015	$ 78	$ 52
ESPP Shares Authorized	4,000,000
Requisite service period	30 days
Maximum percentage of base salary, that company may withhold	25.00%
Purchase price of stock as a percentage to fair market value of the stock	95.00%
Maximum purchases that can be made during each calendar year by participant	25,000
ESPP Shares Acquired	53,434	68,700	93,813
ESPP Withholdings	$ 1.4
Performance Stock Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period (in years)	3 years
Performance Stock Units [Member] | Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting percentage	0.00%
Performance Stock Units [Member] | Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting percentage	150.00%

Leases and Other Commitments (D

Leases and Other Commitments (Details) $ in Millions	Sep. 30, 2015USD ($)
Operating Leases, Future Minimum Payments Due, Fiscal Year Maturity [Abstract]
Operating Leases, Future Minimum Payments Due, Total	$ 374.6
Operating Leases Future Minimum Payments, Due Current	74.2
Operating Leases Future Minimum Payments Due In Two Years	63.3
Operating Leases Future Minimum Payments Due In Three Years	56.6
Operating Leases Future Minimum Payments Due In Four Years	45.7
Operating Leases Future Minimum Payments Due In Five Years	36.6
Operating Leases Future Minimum Payments Due Thereafter	$ 98.2

Leases and Other Commitments 79

Leases and Other Commitments (Details 2) - USD ($) $ in Millions	12 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2013
Commitments and Contingencies Disclosure [Abstract]
Lease And Rental Expense	$ 88.9	$ 81.8	$ 79.6

Leases and Other Commitments 80

Leases and Other Commitments (Details 3) - Outsourced Corporate And Information Technology Activities [Member] $ in Millions	Sep. 30, 2015USD ($)
Other Commitment, Fiscal Year Maturity [Abstract]
Other Commitment	$ 77.6
Other Commitment, Due in Next Twelve Months	$ 38.9

Employee Severance, Litigatio81

Employee Severance, Litigation, and Other (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2013
Restructuring Charges Abstract
Employee severance and other									$ 5,336	$ 1,913	$ 491
Deal-related transaction costs									32,558	6,279	22,976
Employee severance, litigation and other	$ 6,895	$ 2,625	$ 24,871	$ 3,503	$ 781	$ 1,142	$ 1,967	$ 4,302	$ 37,894	$ 8,192	$ 23,467

Litigation Settlements (Details

Litigation Settlements (Details) - USD ($) $ in Thousands	3 Months Ended						12 Months Ended
	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2013
Litigation Settlements [Abstract]
Gain (Loss) Related to Litigation Settlement	$ 400	$ 43,600	$ 21,500	$ 2,500	$ 800	$ 21,000	$ 65,493	$ 24,436	$ 22,883

Business Segment Information (D

Business Segment Information (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2013
Segment Reporting Information [Line Items]
Distribution of Pharmaceuticals as Historic Percentage of Total Revenue									95.00%
Revenues	$ 35,470,378	$ 34,233,556	$ 32,669,267	$ 33,588,602	$ 31,588,708	$ 30,348,154	$ 28,455,903	$ 29,176,362	$ 135,961,803	$ 119,569,127	$ 87,959,167
Operating income	537,451	332,565	(364,249)	(88,397)	207,263	110,877	301,128	159,616	417,370	778,884	898,399
Gain (Loss) Related to Litigation Settlement	400	43,600	21,500			2,500	800	21,000	65,493	24,436	22,883
LIFO expense	(88,900)	(158,700)	(151,100)	(144,000)	(54,400)	(133,200)	(102,800)	(57,600)	(542,807)	(348,063)	(277,001)
Acquisition - related intangibles amortization									(54,095)	(23,167)	(24,387)
Warrant expense	196,487	14,900	(752,706)	(371,405)	(155,739)	(145,040)	(5,663)	(116,297)	(912,724)	(422,739)	(90,055)
Employee severance, litigation and other	(6,895)	$ (2,625)	$ (24,871)	$ (3,503)	(781)	$ (1,142)	$ (1,967)	$ (4,302)	(37,894)	(8,192)	(23,467)
Other loss (income)									13,598	(4,360)	44
Impairment charge on equity investment									30,622	0	0
Interest expense, net									99,001	76,862	73,897
Loss on early retirement of debt									0	32,954	0
Income from continuing operations before income taxes									274,149	673,428	824,458
Assets	27,736,157				21,532,183				27,736,157	21,532,183
Depreciation and amortization									243,280	185,290	162,186
Capital expenditures									231,585	264,457	202,450
Intersegment Elimination [Member]
Segment Reporting Information [Line Items]
Revenues									(290,925)	(263,989)	(192,332)
Operating Segments [Member]
Segment Reporting Information [Line Items]
Operating income									1,899,397	1,556,609	1,290,426
Pharmaceutical Distribution [Member]
Segment Reporting Information [Line Items]
Revenues									131,480,550	117,383,967	86,063,531
Operating income									1,644,891	1,405,992	1,162,352
Assets	22,469,558				20,009,181				22,469,558	20,009,181
Depreciation and amortization									150,198	131,782	109,401
Capital expenditures									179,870	222,985	170,989
Other Segments [Member]
Segment Reporting Information [Line Items]
Revenues									4,772,178	2,449,149	2,087,968
Operating income									254,506	150,617	128,074
Assets	$ 5,266,599				$ 1,523,002				5,266,599	1,523,002
Depreciation and amortization									38,987	30,340	28,398
Capital expenditures									$ 51,715	$ 41,472	$ 31,461

Fair Value of Financial Instr84

Fair Value of Financial Instruments (Details) - USD ($) $ in Millions	Sep. 30, 2015	Sep. 30, 2014
Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract]
Available-for-sale securities	$ 86.2	$ 0
Fixed Income Securities [Member]
Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract]
Amortized costs of investments	213.1
Reported Value Measurement [Member]
Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract]
Long-term debt	3,493	1,995.6
Estimate of Fair Value Measurement [Member] | Fair Value, Inputs, Level 1 [Member] | Money Market Accounts [Member]
Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract]
Cash and cash equivalents	0	400
Estimate of Fair Value Measurement [Member] | Fair Value, Inputs, Level 2 [Member]
Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract]
Long-term debt	3,515.1	$ 2,056.6
Estimate of Fair Value Measurement [Member] | Fair Value, Inputs, Level 2 [Member] | Fixed Income Securities [Member]
Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract]
Available-for-sale securities	213.1
Estimate of Fair Value Measurement [Member] | Fair Value, Inputs, Level 2 [Member] | Fixed Income Securities [Member] | Cash and Cash Equivalents [Member]
Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract]
Available-for-sale securities	$ 126.9

Quarterly Financial Informati85

Quarterly Financial Information (Unaudited) (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2013
Quarterly Financial Information Disclosure [Abstract]
Revenue	$ 35,470,378	$ 34,233,556	$ 32,669,267	$ 33,588,602	$ 31,588,708	$ 30,348,154	$ 28,455,903	$ 29,176,362	$ 135,961,803	$ 119,569,127	$ 87,959,167
Gross Profit (a)	973,574	891,464	911,976	752,299	872,544	692,004	729,593	688,225	3,529,313	2,982,366	2,507,819
Distribution, selling and administrative expenses, depreciation and amortization	625,715	571,174	498,648	465,788	508,761	434,945	420,835	408,010	2,161,325	1,772,551
Warrant expense	(196,487)	(14,900)	752,706	371,405	155,739	145,040	5,663	116,297	912,724	422,739	90,055
Employee severance, litigation and other	6,895	2,625	24,871	3,503	781	1,142	1,967	4,302	37,894	8,192	23,467
Operating income	537,451	332,565	(364,249)	(88,397)	207,263	110,877	301,128	159,616	417,370	778,884	898,399
Income (loss) from continuing operations					67,802	(12,780)	180,077	48,931	(134,887)	284,030	493,435
Loss from discontinued operations, net of tax (b)					0	0	0	(7,546)	0	(7,546)	(59,728)
Net (loss) income	$ 364,287	$ 214,163	$ (513,390)	$ (199,947)	$ 67,802	$ (12,780)	$ 180,077	$ 41,385	$ (134,887)	$ 276,484	$ 433,707
Earnings Per Share From Continuing Operations [Abstract]
Basic (in dollars per share)					$ 0.30	$ (0.06)	$ 0.78	$ 0.21	$ (0.62)	$ 1.25	$ 2.14
Diluted (in dollars per share)					0.29	(0.06)	0.76	0.21	(0.62)	1.21	2.10
Earnings Per Share From Net Income [Abstract]
Basic (in dollars per share)	$ 1.72	$ 0.98	$ (2.33)	$ (0.91)	0.30	(0.06)	0.78	0.18	(0.62)	1.22	1.88
Diluted (in dollars per share)	$ 1.56	$ 0.89	$ (2.33)	$ (0.91)	$ 0.29	$ (0.06)	$ 0.76	$ 0.17	$ (0.62)	$ 1.17	$ 1.84
Gain (Loss) Related to Litigation Settlement	$ 400	$ 43,600	$ 21,500			$ 2,500	$ 800	$ 21,000	$ 65,493	$ 24,436	$ 22,883
Inventory, LIFO Reserve, Period Charge	$ 88,900	$ 158,700	$ 151,100	$ 144,000	$ 54,400	$ 133,200	$ 102,800	$ 57,600	$ 542,807	$ 348,063	$ 277,001

Subsequent Events (Details)

Subsequent Events (Details) - USD ($) $ / shares in Units, $ in Millions	Nov. 06, 2015	Nov. 30, 2015	Mar. 31, 2013	Dec. 31, 2015	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2013
Income Taxes
Full Value of Warrants			$ 242.4		$ 1,917.9
Warrants, term			10 years
Applicable tax rate					149.20%	57.80%	40.20%
Subsequent Event [Member]
Dividend Increase
Dividend increase percentage		17.00%
Quarterly cash dividend declared per share of common stock		$ 0.34
Subsequent Event [Member] | Secured Debt [Member] | Secured Debt [Member] | Variable Rate Term Loan [Member]
Acquisition
Maximum borrowing capacity		$ 1,000
Scheduled principal payment		$ 25
Subsequent Event [Member] | PharMEDium Healthcare Holdings, Inc [Member]
Acquisition
Cash paid to acquire business including purchase price adjustments	$ 2,700
Scenario, Forecast [Member] | Subsequent Event [Member]
Income Taxes
Tax benefit, warrants				$ 456
Applicable tax rate				36.50%
Minimum [Member] | Base Rate [Member] | Subsequent Event [Member] | Secured Debt [Member] | Secured Debt [Member] | Variable Rate Term Loan [Member]
Acquisition
Variable rate spread (as a percent)		0.00%
Minimum [Member] | London Interbank Offered Rate LIBOR [Member] | Subsequent Event [Member] | Secured Debt [Member] | Secured Debt [Member] | Variable Rate Term Loan [Member]
Acquisition
Variable rate spread (as a percent)		0.75%
Maximum [Member] | Base Rate [Member] | Subsequent Event [Member] | Secured Debt [Member] | Secured Debt [Member] | Variable Rate Term Loan [Member]
Acquisition
Variable rate spread (as a percent)		0.25%
Maximum [Member] | London Interbank Offered Rate LIBOR [Member] | Subsequent Event [Member] | Secured Debt [Member] | Secured Debt [Member] | Variable Rate Term Loan [Member]
Acquisition
Variable rate spread (as a percent)		1.25%

Schedule II Valuation and Qua87

Schedule II Valuation and Qualifying Accounts (Details) - Allowance for Returns and Doubtful Accounts [Member] - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2013
Movement in Valuation Allowances and Reserves [Roll Forward]
Balance of Allowance at Beginning of Period	$ 1,022,052	$ 358,161	$ 338,245
Valuation Allowances And Reserves Charged To Cost And Expense	2,721,263	3,643,663	1,099,905
Valuation Allowances And Reserves Deductions	(2,819,560)	(2,979,772)	(1,079,989)
Balance of Allowance at End of Period	$ 923,755	$ 1,022,052	$ 358,161

Schedule II Valuation and Qua88

Schedule II Valuation and Qualifying Accounts (Details 2) - USD ($) $ in Thousands	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2013
Allowance for Doubtful Accounts, Noncurrent [Member] | Other Noncurrent Assets [Member]
Valuation and Qualifying Accounts Disclosure [Line Items]
Allowance for doubtful accounts for long-term accounts receivable	$ 23,991	$ 23,668	$ 0