Summary of Significant Accounting Policies	12 Months Ended
Sep. 30, 2017
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	Summary of Significant Accounting Policies Basis of Presentation The accompanying Consolidated Financial Statements and Notes to Consolidated Financial Statements of Becton, Dickinson and Company (the “Company”) have been prepared in accordance with U.S. generally accepted accounting principles. Within the financial statements and tables presented, certain columns and rows may not add due to the use of rounded numbers for disclosure purposes. Percentages and earnings per share amounts presented are calculated from the underlying amounts. Our fiscal year ends on September 30. Principles of Consolidation The consolidated financial statements include the Company’s accounts and those of its majority-owned subsidiaries after the elimination of intercompany transactions. The Company has no material interests in variable interest entities. Cash Equivalents Cash equivalents consist of all highly liquid investments with a maturity of three months or less at time of purchase. Short-Term Investments Short-term investments consist of time deposits with maturities greater than three months and less than one year when purchased. Trade and Financing Receivables The Company grants credit to customers in the normal course of business and the resulting trade receivables are stated at their net realizable value. The allowance for doubtful accounts represents the Company’s estimate of probable credit losses relating to trade receivables and is determined based on historical experience and other specific account data. Amounts are written off against the allowances for doubtful accounts when the Company determines that a customer account is uncollectible. Inventories Inventories are stated at the lower of first-in, first-out cost or market. Property, Plant and Equipment Property, plant and equipment are stated at cost, less accumulated depreciation and amortization. Depreciation and amortization are principally provided on the straight-line basis over estimated useful lives, which range from 20 to 45 years for buildings, four to 13 years for machinery and equipment and one to 12 years for leasehold improvements. Depreciation and amortization expense was $406 million, $452 million and $417 million in fiscal years 2017, 2016 and 2015, respectively. Goodwill and Other Intangible Assets The Company’s unamortized intangible assets include goodwill and in-process research and development assets which arise from acquisitions. The Company currently reviews all indefinite-lived assets, including goodwill, for impairment using quantitative models. Goodwill is reviewed at least annually for impairment at the reporting unit level, which is defined as an operating segment or one level below an operating segment, referred to as a component. The Company’s reporting units generally represent one level below reporting segments, and components within an operating segment that have similar economic characteristics are aggregated. Potential impairment of goodwill is identified by comparing the fair value of a reporting unit, estimated using an income approach, with its carrying value. The annual impairment review performed on July 1, 2017 indicated that all identified reporting units’ fair values exceeded their respective carrying values. The review for impairment of in-process research and development assets is performed by comparing the fair value of the technology or project assets, estimated using an income approach, with their carrying value. In-process research and development assets are considered indefinite-lived assets and are reviewed at least annually for impairment until projects are completed or abandoned. Certain trademarks that are considered to generate cash flows indefinitely are also considered to be indefinite-lived intangible assets and these assets are also reviewed at least annually for impairment. Amortized intangible assets include developed technology assets which arise from acquisitions. These assets represent acquired intellectual property that is already technologically feasible upon the acquisition date or acquired in-process research and development assets that are completed subsequent to acquisition. Developed technology assets are generally amortized over periods ranging from 15 to 20 years, using the straight-line method. Other intangibles with finite useful lives, which include patents, are amortized over periods principally ranging from one to 40 years, using the straight-line method. Finite-lived intangible assets, including developed technology assets, are periodically reviewed when impairment indicators are present to assess recoverability from future operations using undiscounted cash flows. The carrying values of these finite-lived assets are compared to the undiscounted cash flows they are expected to generate and an impairment loss is recognized in operating results to the extent any finite-lived intangible asset’s carrying value exceeds its calculated fair value. Foreign Currency Translation Generally, foreign subsidiaries’ functional currency is the local currency of operations and the net assets of foreign operations are translated into U.S. dollars using current exchange rates. The U.S. dollar results that arise from such translation, as well as exchange gains and losses on intercompany balances of a long-term investment nature, are included in the foreign currency translation adjustments in Accumulated other comprehensive income (loss). Revenue Recognition Revenue from product sales is typically recognized when all of the following criteria have been met: persuasive evidence of an arrangement exists; delivery has occurred or services have been rendered; product price is fixed or determinable; collection of the resulting receivable is reasonably assured. Certain sales arrangements contain multiple deliverables, including equipment and service deliverables, which requires the Company to determine the separate units of account. If the deliverable meets the criteria of a separate unit of accounting, the arrangement consideration is allocated to each element based upon its relative selling price. In determining the best evidence of selling price of a unit of account the Company utilizes vendor-specific objective evidence (“VSOE”), which is the price the Company charges when the deliverable is sold separately. When VSOE is not available, management uses relevant third-party evidence (“TPE”) of selling price, if available. When neither VSOE nor TPE of selling price exists, management uses its best estimate of selling price. Revenue allocated to equipment deliverables is recognized upon customer acceptance, which occurs after the transfer of title and risk of loss to the customer and the completion of installation or training services. When related training services are considered inconsequential, delivery is deemed to occur upon the transfer of title and risk of loss, at which time revenue and the costs associated with installation and training are recognized. For equipment lease revenue, transactions are evaluated and classified as either operating leases or sales-type leases. Lease income for products sold under sales-type leases is recognized as revenue upon the completion of installation activities in the amount of the present value of the minimum lease payments. The financing component of sales-type leases is recorded as revenue over the lease term. For products sold under operating leases, revenue is recognized at the contracted rate over the rental period, as defined within the customer agreement. For products sold and leased with embedded software, if software is considered not essential to the non-software elements of a product but is considered more than incidental to a product as a whole, the product’s software elements must be separated from its non-software elements under the requirements relating to multiple-element arrangements and accounted for under software industry-specific revenue recognition requirements. However, if it is determined that the embedded software is more than incidental to the product as a whole but the non-software elements and software elements work together to deliver the essential functionality of the products as a whole, then the accounting for such product does not fall within the scope of software industry-specific accounting requirements. The Company’s domestic businesses sell products primarily to distributors that resell the products to end-user customers. Rebates are provided to distributors that sell to end-user customers at prices determined under a contract between the Company and the end-user customer. Provisions for rebates, as well as sales discounts and returns, are based upon estimates and are accounted for as a reduction of revenues when revenue is recognized. Shipping and Handling Costs Shipping and handling costs are included in Selling and administrative expense. Shipping expense was $365 million, $401 million and $351 million in 2017, 2016 and 2015, respectively. Derivative Financial Instruments All derivatives are recorded in the balance sheet at fair value and changes in fair value are recognized currently in earnings unless specific hedge accounting criteria are met. Any deferred gains or losses associated with derivative instruments are recognized in income in the period in which the underlying hedged transaction is recognized. Additional disclosures regarding the Company's accounting for derivative instruments are provided in Note 13. Income Taxes United States income taxes are not provided on undistributed earnings of foreign subsidiaries where such undistributed earnings are indefinitely reinvested outside the United States. Deferred taxes are provided for earnings of foreign subsidiaries when those earnings are not considered indefinitely reinvested. Income taxes are provided and tax credits are recognized based on tax laws enacted at the dates of the financial statements. The Company conducts business and files tax returns in numerous countries and currently has tax audits in progress in a number of tax jurisdictions. In evaluating the exposure associated with various tax filing positions, the Company records accruals for uncertain tax positions, based on the technical support for the positions, past audit experience with similar situations, and the potential interest and penalties related to the matters. The Company maintains valuation allowances where it is more likely than not that all or a portion of a deferred tax asset will not be realized. Changes in valuation allowances are included in the tax provision in the period of change. In determining whether a valuation allowance is warranted, management evaluates factors such as prior earnings history, expected future earnings, carryback and carryforward periods and tax strategies that could potentially enhance the likelihood of the realization of a deferred tax asset. Additional disclosures regarding the Company's accounting for income taxes are provided in Note 16. Earnings per Share Basic earnings per share are computed by dividing income available to common stockholders by the weighted average number of common shares outstanding. Diluted earnings per share reflect the potential dilution that could occur if securities or other contracts to issue common stock were exercised or converted into common stock. In computing diluted earnings per share, only potential common shares that are dilutive (i.e., those that reduce earnings per share or increase loss per share) are included in the calculation. Use of Estimates The preparation of financial statements in conformity with U.S. generally accepted accounting principles requires management to make estimates and assumptions. These estimates or assumptions affect reported assets, liabilities, revenues and expenses as reflected in the consolidated financial statements. Actual results could differ from these estimates.

Summary of Significant Accounting Policies

Basis of Presentation

The accompanying Consolidated Financial Statements and Notes to Consolidated Financial Statements of Becton, Dickinson and Company (the “Company”) have been prepared in accordance with U.S. generally accepted accounting principles. Within the financial statements and tables presented, certain columns and rows may not add due to the use of rounded numbers for disclosure purposes. Percentages and earnings per share amounts presented are calculated from the underlying amounts. Our fiscal year ends on September 30.

Principles of Consolidation

The consolidated financial statements include the Company’s accounts and those of its majority-owned subsidiaries after the elimination of intercompany transactions. The Company has no material interests in variable interest entities.

Cash Equivalents

Cash equivalents consist of all highly liquid investments with a maturity of three months or less at time of purchase.

Short-Term Investments

Short-term investments consist of time deposits with maturities greater than three months and less than one year when purchased.

Trade and Financing Receivables

The Company grants credit to customers in the normal course of business and the resulting trade receivables are stated at their net realizable value. The allowance for doubtful accounts represents the Company’s estimate of probable credit losses relating to trade receivables and is determined based on historical experience and other specific account data. Amounts are written off against the allowances for doubtful accounts when the Company determines that a customer account is uncollectible.

Inventories

Inventories are stated at the lower of first-in, first-out cost or market.

Property, Plant and Equipment

Property, plant and equipment are stated at cost, less accumulated depreciation and amortization. Depreciation and amortization are principally provided on the straight-line basis over estimated useful lives, which range from 20 to 45 years for buildings, four to 13 years for machinery and equipment and one to 12 years for leasehold improvements. Depreciation and amortization expense was $406 million, $452 million and $417 million in fiscal years 2017, 2016 and 2015, respectively.

Goodwill and Other Intangible Assets

The Company’s unamortized intangible assets include goodwill and in-process research and development assets which arise from acquisitions. The Company currently reviews all indefinite-lived assets, including goodwill, for impairment using quantitative models. Goodwill is reviewed at least annually for impairment at the reporting unit level, which is defined as an operating segment or one level below an operating segment, referred to as a component. The Company’s reporting units generally represent one level below reporting segments, and components within an operating segment that have similar economic characteristics are aggregated. Potential impairment of goodwill is identified by comparing the fair value of a reporting unit, estimated using an income approach, with its carrying value. The annual impairment review performed on July 1, 2017 indicated that all identified reporting units’ fair values exceeded their respective carrying values.

The review for impairment of in-process research and development assets is performed by comparing the fair value of the technology or project assets, estimated using an income approach, with their carrying value. In-process research and development assets are considered indefinite-lived assets and are reviewed at least annually for impairment until projects are completed or abandoned. Certain trademarks that are considered to generate cash flows indefinitely are also considered to be indefinite-lived intangible assets and these assets are also reviewed at least annually for impairment.

Amortized intangible assets include developed technology assets which arise from acquisitions. These assets represent acquired intellectual property that is already technologically feasible upon the acquisition date or acquired in-process research and development assets that are completed subsequent to acquisition. Developed technology assets are generally amortized over periods ranging from 15 to 20 years, using the straight-line method. Other intangibles with finite useful lives, which include patents, are amortized over periods principally ranging from one to 40 years, using the straight-line method. Finite-lived intangible assets, including developed technology assets, are periodically reviewed when impairment indicators are present to assess recoverability from future operations using undiscounted cash flows. The carrying values of these finite-lived assets are compared to the undiscounted cash flows they are expected to generate and an impairment loss is recognized in operating results to the extent any finite-lived intangible asset’s carrying value exceeds its calculated fair value.

Foreign Currency Translation

Generally, foreign subsidiaries’ functional currency is the local currency of operations and the net assets of foreign operations are translated into U.S. dollars using current exchange rates. The U.S. dollar results that arise from such translation, as well as exchange gains and losses on intercompany balances of a long-term investment nature, are included in the foreign currency translation adjustments in Accumulated other comprehensive income (loss).

Revenue Recognition

Revenue from product sales is typically recognized when all of the following criteria have been met: persuasive evidence of an arrangement exists; delivery has occurred or services have been rendered; product price is fixed or determinable; collection of the resulting receivable is reasonably assured. Certain sales arrangements contain multiple deliverables, including equipment and service deliverables, which requires the Company to determine the separate units of account. If the deliverable meets the criteria of a separate unit of accounting, the arrangement consideration is allocated to each element based upon its relative selling price. In determining the best evidence of selling price of a unit of account the Company utilizes vendor-specific objective evidence (“VSOE”), which is the price the Company charges when the deliverable is sold separately. When VSOE is not available, management uses relevant third-party evidence (“TPE”) of selling price, if available. When neither VSOE nor TPE of selling price exists, management uses its best estimate of selling price.

Revenue allocated to equipment deliverables is recognized upon customer acceptance, which occurs after the transfer of title and risk of loss to the customer and the completion of installation or training services. When related training services are considered inconsequential, delivery is deemed to occur upon the transfer of title and risk of loss, at which time revenue and the costs associated with installation and training are recognized.

For equipment lease revenue, transactions are evaluated and classified as either operating leases or sales-type leases. Lease income for products sold under sales-type leases is recognized as revenue upon the completion of installation activities in the amount of the present value of the minimum lease payments. The financing component of sales-type leases is recorded as revenue over the lease term. For products sold under operating leases, revenue is recognized at the contracted rate over the rental period, as defined within the customer agreement.

For products sold and leased with embedded software, if software is considered not essential to the non-software elements of a product but is considered more than incidental to a product as a whole, the product’s software elements must be separated from its non-software elements under the requirements relating to multiple-element arrangements and accounted for under software industry-specific revenue recognition requirements. However, if it is determined that the embedded software is more than incidental to the product as a whole but the non-software elements and software elements work together to deliver the essential functionality of the products as a whole, then the accounting for such product does not fall within the scope of software industry-specific accounting requirements.

The Company’s domestic businesses sell products primarily to distributors that resell the products to end-user customers. Rebates are provided to distributors that sell to end-user customers at prices determined under a contract between the Company and the end-user customer. Provisions for rebates, as well as sales discounts and returns, are based upon estimates and are accounted for as a reduction of revenues when revenue is recognized.

Shipping and Handling Costs

Shipping and handling costs are included in Selling and administrative expense. Shipping expense was $365 million, $401 million and $351 million in 2017, 2016 and 2015, respectively.

Derivative Financial Instruments

All derivatives are recorded in the balance sheet at fair value and changes in fair value are recognized currently in earnings unless specific hedge accounting criteria are met. Any deferred gains or losses associated with derivative instruments are recognized in income in the period in which the underlying hedged transaction is recognized. Additional disclosures regarding the Company's accounting for derivative instruments are provided in Note 13.

Income Taxes

United States income taxes are not provided on undistributed earnings of foreign subsidiaries where such undistributed earnings are indefinitely reinvested outside the United States. Deferred taxes are provided for earnings of foreign subsidiaries when those earnings are not considered indefinitely reinvested. Income taxes are provided and tax credits are recognized based on tax laws enacted at the dates of the financial statements.

The Company conducts business and files tax returns in numerous countries and currently has tax audits in progress in a number of tax jurisdictions. In evaluating the exposure associated with various tax filing positions, the Company records accruals for uncertain tax positions, based on the technical support for the positions, past audit experience with similar situations, and the potential interest and penalties related to the matters.

The Company maintains valuation allowances where it is more likely than not that all or a portion of a deferred tax asset will not be realized. Changes in valuation allowances are included in the tax provision in the period of change. In determining whether a valuation allowance is warranted, management evaluates factors such as prior earnings history, expected future earnings, carryback and carryforward periods and tax strategies that could potentially enhance the likelihood of the realization of a deferred tax asset. Additional disclosures regarding the Company's accounting for income taxes are provided in Note 16.

Earnings per Share

Basic earnings per share are computed by dividing income available to common stockholders by the weighted average number of common shares outstanding. Diluted earnings per share reflect the potential dilution that could occur if securities or other contracts to issue common stock were exercised or converted into common stock. In computing diluted earnings per share, only potential common shares that are dilutive (i.e., those that reduce earnings per share or increase loss per share) are included in the calculation.

Use of Estimates

The preparation of financial statements in conformity with U.S. generally accepted accounting principles requires management to make estimates and assumptions. These estimates or assumptions affect reported assets, liabilities, revenues and expenses as reflected in the consolidated financial statements. Actual results could differ from these estimates.