Air Products and Chemicals (APD) 10-K 16 Nov 17 2017 FY Annual report Financial data

Document and Entity Information

Document and Entity Information - USD ($) $ in Billions	12 Months Ended
	Sep. 30, 2017	Oct. 31, 2017	Mar. 31, 2017
Document And Entity Information [Abstract]
Document Type	10-K
Amendment Flag	false
Document Period End Date	Sep. 30, 2017
Document Fiscal Year Focus	2,017
Document Fiscal Period Focus	FY
Current Fiscal Year End Date	--09-30
Entity Registrant Name	AIR PRODUCTS & CHEMICALS INC /DE/
Entity Central Index Key	2,969
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Filer Category	Large Accelerated Filer
Entity Public Float			$ 29.3
Entity Common Stock, Shares Outstanding		218,618,346

Consolidated Income Statements

Consolidated Income Statements - USD ($) shares in Millions, $ in Millions	12 Months Ended
	Sep. 30, 2017		Sep. 30, 2016		Sep. 30, 2015
Income Statement [Abstract]
Sales	$ 8,187.6		$ 7,503.7		$ 7,824.3
Cost of sales	5,753.4		5,176.6		5,598.2
Selling and administrative	715.6		685		773
Research and development	57.8		71.6		76.4
Business separation costs	30.2	[1]	50.6	[1]	7.5
Business restructuring and cost reduction actions	151.4	[2]	34.5	[2]	180.1
Pension settlement loss	10.5	[3]	5.1	[3]	19.3
Goodwill and intangible asset impairment charge	162.1	[4]	0		0
Gain on previously held equity interest	0		0		17.9
Other income (expense), net	121		49.4		45.5
Operating Income	1,427.6	[5]	1,529.7	[5]	1,233.2
Equity affiliates' income	80.1	[6]	147		152.3
Interest expense	120.6		115.2		102.8
Other non-operating income (expense), net	29		0		0
Loss on extinguishment of debt	0		6.9	[7]	16.6
Income From Continuing Operations Before Taxes	1,416.1		1,554.6		1,266.1
Income tax provision	260.9	[8]	432.6	[9]	300.2
Income From Continuing Operations	1,155.2		1,122		965.9
Income (Loss) From Discontinued Operations, net of tax	1,866		(460.5)		351.7
Net Income	3,021.2		661.5		1,317.6
Net Income Attributable to Noncontrolling Interests of Continuing Operations	20.8		22.5		32.6
Net Income Attributable to Noncontrolling Interests of Discontinued Operations	0		7.9		7.1
Net Income Attributable to Air Products	3,000.4		631.1		1,277.9
Net Income Attributable to Air Products
Income from continuing operations	1,134.4		1,099.5		933.3
Income (Loss) from discontinued operations	1,866	[10]	(468.4)		344.6
Net Income Attributable to Air Products	$ 3,000.4		$ 631.1		$ 1,277.9
Basic Earnings Per Common Share Attributable to Air Products
Income from continuing operations (in dollars per share)	$ 5.20		$ 5.08		$ 4.34
Income (Loss) from discontinued operations (in dollars per share)	8.56		(2.16)		1.61
Net Income Attributable to Air Products (in dollars per share)	13.76		2.92		5.95
Diluted Earnings Per Common Share Attributable to Air Products
Income from continuing operations (in dollars per share)	5.16		5.04		4.29
Income (Loss) from discontinued operations (in dollars per share)	8.49		(2.15)		1.59
Net Income Attributable to Air Products (in dollars per share)	$ 13.65		$ 2.89		$ 5.88
Weighted Average Common Shares - Basic (in millions)	218		216.4		214.9
Weighted Average Common Shares - Diluted (in millions)	219.8		218.3		217.3
[1]	For additional information, see Note 4, Materials Technologies Separation.
[2]	For additional information, see Note 5, Business Restructuring and Cost Reduction Actions.
[3]	For additional information, see Note 16, Retirement Benefits.
[4]	For additional information, see Note 10, Goodwill, and Note 11, Intangible Assets.
[5]	Changes in estimates on projects accounted for under the percentage of completion method favorably impacted income by approximately $27 in fiscal year 2017 and $20 in fiscal year 2016, primarily during the fourth quarter. For additional information, see Note 1, Major Accounting Policies (Revenue Recognition).
[6]	Includes the impact of an other-than-temporary impairment of an investment in an equity affiliate. For additional information, see Note 8, Summarized Financial Information of Equity Affiliates.
[7]	For additional information, see Note 15, Debt.
[8]	Includes the impact of a tax election benefit related to a non-U.S. subsidiary. For additional information, see Note 22, Income Taxes.
[9]	Includes income tax expense for tax costs associated with business separation. For additional information, see Note 4, Materials Technologies Separation.
[10]	Includes the after-tax gain on the sale of PMD. For additional information, see Note 3, Discontinued Operations.

Consolidated Comprehensive Inco

Consolidated Comprehensive Income Statements - USD ($) $ in Millions	12 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2015
Statement of Comprehensive Income [Abstract]
Net Income	$ 3,021.2	$ 661.5	$ 1,317.6
Other Comprehensive Income (Loss), net of tax:
Translation adjustments, net of tax of ($19.3), ($19.8), and $45.2	101.9	9.9	(699.3)
Net gain (loss) on derivatives, net of tax of ($11.0), $9.1, and ($16.0)	(12.6)	13.7	(35)
Pension and postretirement benefits, net of tax of $109.0, ($157.4), and ($148.5)	251.6	(335.1)	(278.5)
Reclassification adjustments:
Currency translation adjustment	57.3	2.7	0
Derivatives, net of tax of $11.7, ($9.4), and $7.0	24.2	(36)	20.8
Pension and postretirement benefits, net of tax of $50.7, $43.0, and $47.7	110.7	87.2	97
Total Other Comprehensive Income (Loss)	533.1	(257.6)	(895)
Comprehensive Income	3,554.3	403.9	422.6
Net Income Attributable to Noncontrolling Interests	20.8	30.4	39.7
Other Comprehensive Income (Loss) Attributable to Noncontrolling Interests	3.7	4.8	(11)
Comprehensive Income Attributable to Air Products	$ 3,529.8	$ 368.7	$ 393.9

Consolidated Comprehensive Inc4

Consolidated Comprehensive Income Statements (Parenthetical) - USD ($) $ in Millions	12 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2015
Statement of Comprehensive Income [Abstract]
Tax effect on translation adjustments	$ (19.3)	$ (19.8)	$ 45.2
Tax effect on net gain (loss) on derivatives	(11)	9.1	(16)
Tax effect on pension and postretirement benefits	109	(157.4)	(148.5)
Tax effect on derivatives reclassification adjustments	11.7	(9.4)	7
Tax effect on pension and postretirement benefits reclassification adjustments	$ 50.7	$ 43	$ 47.7

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Millions		Sep. 30, 2017	Sep. 30, 2016
Current Assets
Cash and cash items		$ 3,273.6	$ 1,293.2
Short-term investments		404	0
Trade receivables, net		1,174	1,146.2
Inventories		335.4	255
Contracts in progress, less progress billings		84.8	64.6
Prepaid expenses		191.4	93.9
Other receivables and current assets		403.3	538.2
Current assets of discontinued operations		10.2	926.2
Total Current Assets		5,876.7	4,317.3
Investment in net assets of and advances to equity affiliates		1,286.9	1,283.6
Plant and equipment, net	[1]	8,440.2	8,259.7
Goodwill, net		721.5	845.1
Intangible assets, net		368.3	387.9
Noncurrent capital lease receivables		1,131.8	1,221.7
Other noncurrent assets		641.8	671
Noncurrent assets of discontinued operations		0	1,042.3
Total Noncurrent Assets		12,590.5	13,711.3
Total Assets		18,467.2	18,028.6
Current Liabilities
Payables and accrued liabilities		1,814.3	1,652.2
Accrued income taxes		98.6	117.9
Short-term borrowings		144	935.8
Current portion of long-term debt		416.4	365.4
Current liabilities of discontinued operations		15.7	211.8
Total Current Liabilities		2,489	3,283.1
Long-term debt		3,402.4	3,909.7
Other noncurrent liabilities		1,611.9	1,816.5
Deferred income taxes		778.4	710.4
Noncurrent liabilities of discontinued operations		0	1,095.5
Total Noncurrent Liabilities		5,792.7	7,532.1
Total Liabilities		8,281.7	10,815.2
Commitments and Contingencies – See Note 17
Air Products Shareholders’ Equity
Common stock (par value $1 per share; issued 2017 and 2016 - 249,455,584 shares)		249.4	249.4
Capital in excess of par value		1,001.1	970
Retained earnings		12,846.6	10,475.5
Accumulated other comprehensive loss		(1,847.4)	(2,388.3)
Treasury stock, at cost (2017 - 31,109,510 shares; 2016 - 32,104,759 shares)		(2,163.5)	(2,227)
Total Air Products Shareholders' Equity		10,086.2	7,079.6
Noncontrolling Interests		99.3	133.8
Total Equity		10,185.5	7,213.4
Total Liabilities and Equity		$ 18,467.2	$ 18,028.6
[1]	Long-lived assets include plant and equipment, net.

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - $ / shares	Sep. 30, 2017	Sep. 30, 2016
Air Products Shareholders’ Equity
Common stock, par value (in dollars per share)	$ 1	$ 1
Common stock, shares issued	249,455,584	249,455,584
Treasury stock, shares	31,109,510	32,104,759

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($) $ in Millions	12 Months Ended
	Sep. 30, 2017		Sep. 30, 2016		Sep. 30, 2015
Operating Activities
Net Income	$ 3,021.2		$ 661.5		$ 1,317.6
Less: Net income attributable to noncontrolling interests of continuing operations	20.8		22.5		32.6
Less: Net income attributable to noncontrolling interests of discontinued operations	0		7.9		7.1
Net Income Attributable to Air Products	3,000.4		631.1		1,277.9
(Income) Loss from discontinued operations attributable to Air Products	(1,866)	[1]	468.4		(344.6)
Income from continuing operations attributable to Air Products	1,134.4		1,099.5		933.3
Adjustments to reconcile income to cash provided by operating activities:
Depreciation and amortization	865.8		854.6		858.5
Deferred income taxes	(38)		61.8		9.4
Loss on extinguishment of debt	0		6.9	[2]	16.6
Gain on previously held equity interest	0		0		(17.9)
Undistributed earnings of unconsolidated affiliates	(60.1)		(51.1)		(101.8)
Gain on sale of assets and investments	(24.3)		(7.3)		(29.7)
Share-based compensation	39.9		31		39.5
Noncurrent capital lease receivables	92.2		85.5		(10.1)
Goodwill and intangible asset impairment charge	162.1	[3]	0		0
Equity method investment impairment charge	79.5		0		0
Write-down of long-lived assets associated with restructuring	69.2		0		40.2
Other adjustments	165.4		156.7		53
Working capital changes that provided (used) cash, excluding effects of acquisitions and divestitures:
Trade receivables	(73.6)		(44.8)		(40.7)
Inventories	6.4		32.2		38
Contracts in progress, less progress billings	(19.3)		28.2		16.9
Other receivables	124.7		(6.7)		48.9
Payables and accrued liabilities	163.8		60.1		134.9
Other working capital	(154)		(47.8)		58
Cash Provided by Operating Activities	2,534.1		2,258.8		2,047
Investing Activities
Additions to plant and equipment	(1,039.7)		(907.7)		(1,162.4)
Acquisitions, less cash acquired	(8.2)		0		(34.5)
Investment in and advances to unconsolidated affiliates	(8.1)		0		(4.3)
Proceeds from sale of assets and investments	42.5		44.6		55.3
Purchases of investments	(2,692.6)		0		0
Proceeds from investments	2,290.7		0		0
Other investing activities	(2.3)		(1.7)		(0.8)
Cash Used for Investing Activities	(1,417.7)		(864.8)		(1,146.7)
Financing Activities
Long-term debt proceeds	2.4		386.9		340.3
Payments on long-term debt	(483.9)		(480.4)		(699.4)
Net (decrease) increase in commercial paper and short-term borrowings	(798.6)		(144.2)		285.2
Dividends paid to shareholders	(787.9)		(721.2)		(677.5)
Proceeds from stock option exercises	68.4		141.3		121.3
Payment for subsidiary shares to noncontrolling interests	0		0		(278.4)
Other financing activities	(41.3)		(42.6)		(51.9)
Cash Used for Financing Activities	(2,040.9)		(860.2)		(960.4)
Discontinued Operations
Cash (used for) provided by operating activities	(966.2)		401.9		422.7
Cash provided by (used for) investing activities	3,750.6		(204.2)		(453)
Cash provided by (used for) financing activities	69.5		555.9		(16.9)
Cash (Used for) Provided by Discontinued Operations	2,853.9		753.6		(47.2)
Effect of Exchange Rate Changes on Cash	13.4		7.5		(22.9)
Increase (Decrease) in cash and cash items	1,942.8		1,294.9		(130.2)
Cash and Cash items – Beginning of Year	1,330.8		206.4		336.6
Cash and Cash Items – End of Period	3,273.6		1,330.8		206.4
Cash and Cash Items – End of Period			1,501.3
Less: Cash and Cash Items – Discontinued Operations	0		208.1		23.3
Cash and Cash Items – Continuing Operations	$ 3,273.6		$ 1,293.2		$ 183.1
[1]	Includes the after-tax gain on the sale of PMD. For additional information, see Note 3, Discontinued Operations.
[2]	For additional information, see Note 15, Debt.
[3]	For additional information, see Note 10, Goodwill, and Note 11, Intangible Assets.

Consolidated Statements of Equi

Consolidated Statements of Equity - USD ($) $ in Millions	Total	Common Stock	Capital in Excess of Par Value	Retained Earnings	Accumulated Other Comprehensive Income (Loss)	Treasury Stock	Air Products Shareholders’ Equity	Non- controlling Interests
Beginning balance at Sep. 30, 2014	$ 7,521.4	$ 249.4	$ 842	$ 9,993.2	$ (1,241.9)	$ (2,476.9)	$ 7,365.8	$ 155.6
Stockholders' Equity [Roll Forward]
Net income	1,306.1			1,277.9			1,277.9	28.2
Other comprehensive income (loss)	(895)				(884)		(884)	(11)
Cash dividends	(687.9)			(687.9)			(687.9)
Share-based compensation expense	43.7		43.7				43.7
Issuance of treasury shares for stock option and award plans	102.2		(15.1)			117.3	102.2
Tax benefit of stock option and award plans	32		32				32
Dividends to noncontrolling interests	(38)							(38)
Purchase of noncontrolling interests	(0.5)		(0.3)				(0.3)	(0.2)
Other	(2.9)		2.4	(2.8)			(0.4)	(2.5)
Ending Balance at Sep. 30, 2015	7,381.1	249.4	904.7	10,580.4	(2,125.9)	(2,359.6)	7,249	132.1
Stockholders' Equity [Roll Forward]
Net income	661.5			631.1			631.1	30.4
Other comprehensive income (loss)	(257.6)				(262.4)		(262.4)	4.8
Cash dividends	(733.7)			(733.7)			(733.7)
Share-based compensation expense	37.6		37.6				37.6
Issuance of treasury shares for stock option and award plans	127.1		(5.5)			132.6	127.1
Tax benefit of stock option and award plans	33.2		33.2				33.2
Dividends to noncontrolling interests	(33.6)							(33.6)
Other	(2.2)			(2.3)			(2.3)	0.1
Ending Balance at Sep. 30, 2016	7,213.4	249.4	970	10,475.5	(2,388.3)	(2,227)	7,079.6	133.8
Stockholders' Equity [Roll Forward]
Net income	3,021.2			3,000.4			3,000.4	20.8
Other comprehensive income (loss)	533.1				529.4		529.4	3.7
Cash dividends	(808.5)			(808.5)			(808.5)
Share-based compensation expense	40.7		40.7				40.7
Issuance of treasury shares for stock option and award plans	53.9		(9.6)			63.5	53.9
Dividends to noncontrolling interests	(28)							(28)
Spin-off of Versum	152.6			175	11.5		186.5	(33.9)
Cumulative change in accounting principle	8.8			8.8			8.8
Other	(1.7)			(4.6)			(4.6)	2.9
Ending Balance at Sep. 30, 2017	$ 10,185.5	$ 249.4	$ 1,001.1	$ 12,846.6	$ (1,847.4)	$ (2,163.5)	$ 10,086.2	$ 99.3

Consolidated Statements of Equ9

Consolidated Statements of Equity (Parenthetical) - $ / shares	3 Months Ended								12 Months Ended
	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2015
Statement of Stockholders' Equity [Abstract]
Dividends per share	$ 0.95	$ 0.95	$ 0.95	$ 0.86	$ 0.86	$ 0.86	$ 0.86	$ 0.81	$ 3.71	$ 3.39	$ 3.20

Major Accounting Policies

Major Accounting Policies	12 Months Ended
	Sep. 30, 2017
Accounting Policies [Abstract]
Major Accounting Policies	1 . MAJOR ACCOUNTING POLICIES Basis of Presentation and Consolidation Principles The accompanying consolidated financial statements of Air Products and Chemicals, Inc. were prepared in accordance with accounting principles generally accepted in the United States of America (“U.S. GAAP”) and include the accounts of Air Products and Chemicals, Inc. and those of its controlled subsidiaries (“we,” “our,” “us,” the “Company,” “Air Products,” or “registrant”), which are generally majority owned. Intercompany transactions and balances are eliminated in consolidation. We consolidate all entities that we control. The general condition for control is ownership of a majority of the voting interests of an entity. Control may also exist in arrangements where we are the primary beneficiary of a variable interest entity (VIE). An entity that has both the power to direct the activities that most significantly impact the economic performance of a VIE and the obligation to absorb the losses or receive the benefits significant to the VIE is considered the primary beneficiary of that entity. We have determined that we are not a primary beneficiary in any material VIE. Reclassifications The results of the divisions comprising the former Materials Technologies segment and the former Energy‑from‑Waste segment have been presented as discontinued operations. Refer to Note 3 , Discontinued Operations , for additional details. The results of operations and cash flows of these businesses have been removed from the results of continuing operations and segment results for all periods presented. The assets and liabilities of the discontinued operations have been reclassified and are segregated in the consolidated balance sheets. The comprehensive income related to these businesses has not been segregated and is included in the consolidated comprehensive income statement for all periods presented. The notes to the consolidated financial statements, unless otherwise indicated, are on a continuing operations basis. The term "total company" includes both continuing and discontinued operations. The consolidated financial statements and accompanying notes reflect accounting guidance that was adopted during fiscal year 2017 . Refer to Note 2 , New Accounting Guidance , for additional information. Certain prior year information has been reclassified to conform to the fiscal year 2017 presentation. Estimates and Assumptions The preparation of the financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect amounts reported in the financial statements and accompanying notes. Actual results could differ from those estimates. Revenue Recognition Revenue from product sales is recognized as risk and title to the product transfer to the customer (which generally occurs at the time shipment is made), the sales price is fixed or determinable, and collectability is reasonably assured. Sales returns and allowances are not a business practice in the industry. Revenue from equipment sale contracts is recorded primarily using the percentage-of-completion method. Under this method, revenue from the sale of major equipment, such as liquefied natural gas (LNG) heat exchangers and large air separation units, is recognized based on costs or labor hours incurred to date compared with total estimated costs or labor hours to be incurred. When adjustments in estimated total contract revenues or estimated total costs or labor hours are required, any changes in the estimated profit from prior estimates are recognized in the current period for the inception-to-date effect of such change. Changes in estimates on projects accounted for under the percentage-of-completion method favorably impacted operating income by approximately $27 in fiscal year 2017 and approximately $20 in fiscal year 2016 . Our changes in estimates would not have significantly impacted amounts recorded in prior years. Changes in estimates during fiscal year 2015 were not significant. Certain contracts associated with facilities that are built to provide product to a specific customer are required to be accounted for as leases. In cases where operating lease treatment is appropriate, there is no difference in revenue recognition over the life of the contract as compared to accounting for the contract as product sales. In cases where capital lease treatment is appropriate, the timing of revenue and expense recognition is impacted. Revenue and expense are recognized up front for the sale of equipment component of the contract as compared to revenue recognition over the life of the arrangement under contracts not qualifying as capital leases. Additionally, a portion of the revenue representing interest income from the financing component of the lease receivable is reflected as sales over the life of the contract. Allowances for credit losses associated with capital lease receivables are recorded using the specific identification method. As of 30 September 2017 and 2016 , the credit quality of capital lease receivables did not require a material allowance for credit losses. If an arrangement involves multiple deliverables, the delivered items are considered separate units of accounting if the items have value on a stand-alone basis. Revenues are allocated to each deliverable based upon relative selling prices derived from company specific evidence. Amounts billed for shipping and handling fees are classified as sales in the consolidated income statements. Amounts billed for sales and use taxes, value-added taxes, and certain excise and other specific transactional taxes imposed on revenue-producing transactions are presented on a net basis and excluded from sales in the consolidated income statements. We record a liability until remitted to the respective taxing authority. Cost of Sales Cost of sales predominantly represents the cost of tangible products sold. These costs include labor, raw materials, plant engineering, power, depreciation, production supplies and materials packaging costs, and maintenance costs. Costs incurred for shipping and handling are also included in cost of sales. Depreciation Depreciation is recorded using the straight-line method, which deducts equal amounts of the cost of each asset from earnings every year over its expected economic useful life. The principal lives for major classes of plant and equipment are summarized in Note 9 , Plant and Equipment, net . Selling and Administrative The principal components of selling and administrative expenses are compensation, advertising, and promotional costs. Selling and administrative expenses also include costs for functional support previously provided to EMD and PMD and in support of transition services agreements with Versum and with Evonik, for which the reimbursement is reflected in "Other income (expense), net" on our consolidated income statements. Postemployment Benefits We provide termination benefits to employees as part of ongoing benefit arrangements and record a liability for termination benefits when probable and estimable. These criteria are met when management, with the appropriate level of authority, approves and commits to its plan of action for termination; the plan identifies the employees to be terminated and their related benefits; and the plan is to be completed within one year. We do not provide material one-time benefit arrangements. Fair Value Measurements We are required to measure certain assets and liabilities at fair value, either upon initial measurement or for subsequent accounting or reporting. For example, fair value is used in the initial measurement of net assets acquired in a business combination; on a recurring basis in the measurement of derivative financial instruments; and on a nonrecurring basis when long-lived assets are written down to fair value when held for sale or determined to be impaired. Refer to Note 14 , Fair Value Measurements , for information on the methods and assumptions used in our fair value measurements. Financial Instruments We address certain financial exposures through a controlled program of risk management that includes the use of derivative financial instruments. The types of derivative financial instruments permitted for such risk management programs are specified in policies set by management. Refer to Note 13 , Financial Instruments , for further detail on the types and use of derivative instruments into which we enter. Major financial institutions are counterparties to all of these derivative contracts. We have established counterparty credit guidelines and generally enter into transactions with financial institutions of investment grade or better. Management believes the risk of incurring losses related to credit risk is remote, and any losses would be immaterial to the consolidated financial results, financial condition, or liquidity. We recognize derivatives on the balance sheet at fair value. On the date the derivative instrument is entered into, we generally designate the derivative as either (1) a hedge of a forecasted transaction or of the variability of cash flows to be received or paid related to a recognized asset or liability (cash flow hedge), (2) a hedge of a net investment in a foreign operation (net investment hedge), or (3) a hedge of the fair value of a recognized asset or liability (fair value hedge). The following details the accounting treatment of our cash flow, fair value, net investment, and non-designated hedges: • Changes in the fair value of a derivative that is designated as and meets the cash flow hedge criteria are recorded in accumulated other comprehensive loss (AOCL) to the extent effective and then recognized in earnings when the hedged items affect earnings. • Changes in the fair value of a derivative that is designated as and meets all the required criteria for a fair value hedge, along with the gain or loss on the hedged asset or liability that is attributable to the hedged risk, are recorded in current period earnings. • Changes in the fair value of a derivative and foreign currency debt that are designated as and meet all the required criteria for a hedge of a net investment are recorded as translation adjustments in AOCL. • Changes in the fair value of a derivative that is not designated as a hedge are recorded immediately in earnings. We formally document the relationships between hedging instruments and hedged items, as well as our risk management objective and strategy for undertaking various hedge transactions. This process includes relating derivatives that are designated as fair value or cash flow hedges to specific assets and liabilities on the balance sheet or to specific firm commitments or forecasted transactions. We also formally assess, at the inception of the hedge and on an ongoing basis, whether derivatives are highly effective in offsetting changes in fair values or cash flows of the hedged item. If it is determined that a derivative is not highly effective as a hedge, or if a derivative ceases to be a highly effective hedge, we will discontinue hedge accounting with respect to that derivative prospectively. Foreign Currency Since we do business in many foreign countries, fluctuations in currency exchange rates affect our financial position and results of operations. In most of our foreign operations, the local currency is considered the functional currency. Foreign subsidiaries translate their assets and liabilities into U.S. dollars at current exchange rates in effect at the end of the fiscal period. The gains or losses that result from this process are shown as translation adjustments in AOCL in the equity section of the balance sheet. The revenue and expense accounts of foreign subsidiaries are translated into U.S. dollars at the average exchange rates that prevail during the period. Therefore, the U.S. dollar value of these items on the income statement fluctuates from period to period, depending on the value of the dollar against foreign currencies. Some transactions are made in currencies different from an entity’s functional currency. Gains and losses from these foreign currency transactions are generally reflected in "Other income (expense), net" on our consolidated income statements as they occur. Environmental Expenditures Accruals for environmental loss contingencies are recorded when it is probable that a liability has been incurred and the amount of loss can be reasonably estimated. Remediation costs are capitalized if the costs improve the Company’s property as compared with the condition of the property when originally constructed or acquired, or if the costs prevent environmental contamination from future operations. We expense environmental costs related to existing conditions resulting from past or current operations and from which no current or future benefit is discernible. The amounts charged to income from continuing operations related to environmental matters totaled $11.4 , $12.2 , and $11.8 in 2017 , 2016 , and 2015 , respectively. The measurement of environmental liabilities is based on an evaluation of currently available information with respect to each individual site and considers factors such as existing technology, presently enacted laws and regulations, and prior experience in remediation of contaminated sites. An environmental liability related to cleanup of a contaminated site might include, for example, a provision for one or more of the following types of costs: site investigation and testing costs, cleanup costs, costs related to soil and water contamination resulting from tank ruptures, post-remediation monitoring costs, and outside legal fees. These liabilities include costs related to other potentially responsible parties to the extent that we have reason to believe such parties will not fully pay their proportionate share. They do not take into account any claims for recoveries from insurance or other parties and are not discounted. As assessments and remediation progress at individual sites, the amount of projected cost is reviewed, and the liability is adjusted to reflect additional technical and legal information that becomes available. Management has an established process in place to identify and monitor the Company’s environmental exposures. An environmental accrual analysis is prepared and maintained that lists all environmental loss contingencies, even where an accrual has not been established. This analysis assists in monitoring the Company’s overall environmental exposure and serves as a tool to facilitate ongoing communication among the Company’s technical experts, environmental managers, environmental lawyers, and financial management to ensure that required accruals are recorded and potential exposures disclosed. Given inherent uncertainties in evaluating environmental exposures, actual costs to be incurred at identified sites in future periods may vary from the estimates. Refer to Note 17 , Commitments and Contingencies , for additional information on the Company’s environmental loss contingencies. The accruals for environmental liabilities are reflected in the consolidated balance sheets, primarily as part of other noncurrent liabilities. Litigation In the normal course of business, we are involved in legal proceedings. We accrue a liability for such matters when it is probable that a liability has been incurred and the amount of loss can be reasonably estimated. When only a range of possible loss can be established, the most probable amount in the range is accrued. If no amount within this range is a better estimate than any other amount within the range, the minimum amount in the range is accrued. The accrual for a litigation loss contingency includes estimates of potential damages and other directly related costs expected to be incurred. Refer to Note 17 , Commitments and Contingencies , for additional information on our current legal proceedings. Share-Based Compensation We have various share-based compensation programs, which include deferred stock units, stock options, and restricted stock. We expense the grant-date fair value of these awards over the vesting period during which employees perform related services. Expense recognition is accelerated for retirement-eligible individuals who would meet the requirements for vesting of awards upon their retirement. Refer to Note 19, Share-Based Compensation, for information on the models and assumptions used to determine the grant-date fair value of our awards. Income Taxes We account for income taxes under the asset and liability method. Under this method, deferred tax assets and liabilities are recognized for the tax effects of temporary differences between the financial reporting and tax bases of assets and liabilities using enacted tax rates in effect for the year in which the differences are expected to be recovered or settled. A principal temporary difference results from the excess of tax depreciation over book depreciation because accelerated methods of depreciation and shorter useful lives are used for income tax purposes. The cumulative impact of a change in tax rates or regulations is included in income tax expense in the period that includes the enactment date. We recognize deferred tax assets net of existing valuation allowance to the extent we believe that these assets are more likely than not to be realized considering all available evidence. A tax benefit for an uncertain tax position is recognized when it is more likely than not that the position will be sustained upon examination based on its technical merits. This position is measured as the largest amount of tax benefit that is greater than 50% likely of being realized. Interest and penalties related to unrecognized tax benefits are recognized as a component of income tax expense. For additional information regarding our income taxes, refer to Note 22 , Income Taxes . Other Non-Operating Income (Expense), net Beginning in the second quarter of fiscal year 2017, other non-operating income (expense), net includes interest income associated with our cash and cash items and short-term investments. Interest income was included in "Other income (expense), net" in 2016 and 2015 . Interest income in previous periods was not material. Cash and Cash Items Cash and cash items include cash, time deposits, treasury securities, and certificates of deposit acquired with an original maturity of three months or less. Short-term investments Short-term investments include time deposits with original maturities greater than three months and less than one year. Trade Receivables, net Trade receivables comprise amounts owed to us through our operating activities and are presented net of allowances for doubtful accounts. The allowances for doubtful accounts represent estimated uncollectible receivables associated with potential customer defaults on contractual obligations. A provision for customer defaults is made on a general formula basis when it is determined that the risk of some default is probable and estimable but cannot yet be associated with specific customers. The assessment of the likelihood of customer defaults is based on various factors, including the length of time the receivables are past due, historical experience, and existing economic conditions. The allowance also includes amounts for certain customers where a risk of default has been specifically identified, considering factors such as the financial condition of the customer and customer disputes over contractual terms and conditions. Allowance for doubtful accounts were $93.5 and $55.3 as of fiscal year end 30 September 2017 and 2016 , respectively. Provisions to the allowance for doubtful accounts charged against income were $45.8 , $21.8 and $25.9 in 2017 , 2016 , and 2015 , respectively. Inventories Inventories are stated at the lower of cost or market. We write down our inventories for estimated obsolescence or unmarketable inventory based upon assumptions about future demand and market conditions. We utilize the last-in, first-out (LIFO) method for determining the cost of inventories in the United States for the Industrial Gases regional and global segments. Inventories for these segments outside of the United States are accounted for on the first-in, first-out (FIFO) method, as the LIFO method is generally not permitted in the foreign jurisdictions where these segments operate. At the business segment level, inventories are recorded at FIFO and the LIFO pool adjustments are not allocated to the business segments. Equity Investments The equity method of accounting is used when we exercise significant influence but do not have operating control, generally assumed to be 20% – 50% ownership. Under the equity method, original investments are recorded at cost and adjusted by our share of undistributed earnings or losses of these companies. Equity investments are reviewed for impairment whenever events or changes in circumstances indicate that the carrying amount of the investment may not be recoverable. Plant and Equipment Plant and equipment is stated at cost less accumulated depreciation. Construction costs, labor, and applicable overhead related to installations are capitalized. Expenditures for additions and improvements that extend the lives or increase the capacity of plant assets are capitalized. The costs of maintenance and repairs of plant and equipment are charged to expense as incurred. Fully depreciated assets are retained in the gross plant and equipment and accumulated depreciation accounts until they are removed from service. In the case of disposals, assets and related depreciation are removed from the accounts, and the net amounts, less proceeds from disposal, are included in income. Refer to Note 9 , Plant and Equipment, net , for further detail. Computer Software We capitalize costs incurred to purchase or develop software for internal use. Capitalized costs include purchased computer software packages, payments to vendors/consultants for development and implementation or modification to a purchased package to meet our requirements, payroll and related costs for employees directly involved in development, and interest incurred while software is being developed. Capitalized computer software costs are reflected in "Plant and equipment, net" on the consolidated balance sheets and are depreciated over the estimated useful life of the software, generally a period of three to ten years. Capitalized Interest As we build new plant and equipment, we include in the cost of these assets a portion of the interest payments we make during the year. The amount of capitalized interest was $19.0 , $32.7 , and $49.1 in 2017 , 2016 , and 2015 , respectively. Impairment of Long-Lived Assets Long-lived assets are grouped for impairment testing at the lowest level for which there are identifiable cash flows that are largely independent of the cash flows of other assets and liabilities and are evaluated for impairment whenever events or changes in circumstances indicate that the carrying amount of an asset group may not be recoverable. We assess recoverability by comparing the carrying amount of the asset group to estimated undiscounted future cash flows expected to be generated by the asset group. If an asset group is considered impaired, the impairment loss to be recognized is measured as the amount by which the asset group’s carrying amount exceeds its fair value. Long-lived assets to be sold are reported at the lower of carrying amount or fair value less cost to sell. Asset Retirement Obligations The fair value of a liability for an asset retirement obligation is recognized in the period in which it is incurred. The fair value of the liability is measured using discounted estimated cash flows and is adjusted to its present value in subsequent periods as accretion expense is recorded. The corresponding asset retirement costs are capitalized as part of the carrying amount of the related long-lived asset and depreciated over the asset’s useful life. Our asset retirement obligations are primarily associated with on-site long-term supply contracts, under which we have built a facility on land owned by the customer and are obligated to remove the facility at the end of the contract term. Our asset retirement obligations totaled $ 144.7 and $119.9 at 30 September 2017 and 2016 , respectively. Goodwill Business combinations are accounted for using the acquisition method. The purchase price is allocated to the assets acquired and liabilities assumed based on their estimated fair market values. Any excess purchase price over the fair market value of the net assets acquired, including identified intangibles, is recorded as goodwill. Preliminary purchase price allocations are made at the date of acquisition and finalized when information needed to affirm underlying estimates is obtained, within a maximum allocation period of one year. Goodwill is subject to impairment testing at least annually. In addition, goodwill is tested more frequently if a change in circumstances or the occurrence of events indicates that potential impairment exists. Refer to Note 10 , Goodwill , for further detail. Intangible Assets Intangible assets with determinable lives primarily consist of customer relationships, purchased patents and technology, and land use rights. The cost of intangible assets with determinable lives is amortized on a straight-line basis over the estimated period of economic benefit. No residual value is estimated for these intangible assets. Indefinite-lived intangible assets consist of trade names and trademarks. Indefinite-lived intangibles are subject to impairment testing at least annually. In addition, intangible assets are tested more frequently if a change in circumstances or the occurrence of events indicates that potential impairment exists. Customer relationships are generally amortized over periods of five to twenty-five years. Purchased patents and technology and other are generally amortized over periods of five to fifteen years. Land use rights, which are included in other intangibles, are generally amortized over a period of fifty years. Amortizable lives are adjusted whenever there is a change in the estimated period of economic benefit. Refer to Note 11 , Intangible Assets , for further detail. Retirement Benefits The cost of pension benefits is recognized over the employees’ service period. We use actuarial methods and assumptions in the valuation of defined benefit obligations and the determination of expense. Differences between actual and expected results or changes in the value of obligations and plan assets are not recognized in earnings as they occur but, rather, systematically and gradually over subsequent periods. Refer to Note 16 , Retirement Benefits , for disclosures related to our pension and other postretirement benefits.

New Accounting Guidance

New Accounting Guidance	12 Months Ended
	Sep. 30, 2017
New Accounting Pronouncements and Changes in Accounting Principles [Abstract]
New Accounting Guidance	2 . NEW ACCOUNTING GUIDANCE Accounting Guidance Implemented in 2017 Simplifying Goodwill Impairment Test In January 2017, the Financial Accounting Standards Board (FASB) issued guidance to simplify the test for goodwill impairment by eliminating Step 2, which measured the impairment loss based on the fair value of goodwill. Under the new guidance, an impairment loss will be recognized for the amount by which the carrying amount of the reporting unit exceeds its fair value, not to exceed the total amount of goodwill allocated to that reporting unit. The guidance is effective for annual or interim goodwill impairments tests conducted in fiscal year 2021, with early adoption permitted, and should be applied prospectively. We elected to early adopt this guidance during the third quarter of fiscal year 2017. Share-Based Compensation In March 2016, the FASB issued an update to simplify the accounting for employee share-based payments, including the income tax impacts, the classification on the statement of cash flows, and forfeitures. We elected to early adopt this guidance in the first quarter of fiscal year 2017. The new guidance requires excess tax benefits and deficiencies to be recognized in the income statement rather than in additional paid-in capital on the balance sheet. As a result of applying this change prospectively, we recognized $17.6 of excess tax benefits in our provision for income taxes during fiscal year 2017. In addition, adoption of the new guidance resulted in an $8.8 cumulative-effect adjustment to retained earnings as of 1 October 2016 to recognize deferred taxes for U.S. state net operating loss and other carryforwards attributable to excess tax benefits. We retrospectively applied the guidance on cash flow presentation, which requires excess tax benefits to be presented as an operating activity rather than as a financing activity. Cash paid on employees’ behalf related to shares withheld for tax purposes continues to be classified as a financing activity. Forfeitures have not been significant historically. We have elected to account for forfeitures as they occur, rather than to estimate them. Share-Based Compensation Modification Accounting In May 2017, the FASB issued an update to amend the scope of modification accounting associated with share-based payment awards. The guidance limits the use of modification accounting to instances where the fair value, vesting conditions, or award classification are different immediately before and after the modification. This guidance is effective in fiscal year 2019, with early adoption permitted, and should be applied prospectively. We adopted this guidance during the fourth quarter of fiscal year 2017. This guidance did not have a significant impact on our consolidated financial statements upon adoption. Consolidation Analysis In February 2015, the FASB issued an update to amend current consolidation guidance. The guidance impacts the analysis an entity must perform in determining if it should consolidate certain legal entities such as limited partnerships, limited liability corporations, and securitization structures. We adopted this guidance in the first quarter of fiscal year 2017. This guidance did not have a significant impact on our consolidated financial statements upon adoption. Debt Issuance Costs In April 2015, the FASB issued guidance requiring that debt issuance costs related to a recognized debt liability be presented in the balance sheet as a direct deduction from the carrying amount of the debt instead of as a separate deferred asset. In addition, guidance was issued to allow for a policy election on the presentation of debt issuance costs associated with a line-of-credit arrangement, regardless of whether there are any outstanding borrowings. We adopted the guidance during the first quarter of fiscal year 2017 on a retrospective basis. The guidance resulted in a reclassification adjustment that decreased other noncurrent assets by $17.0 with a corresponding decrease to long-term debt as of 30 September 2016. We will continue to present debt issuance costs associated with a line-of-credit arrangement as a deferred asset, regardless of whether there are any outstanding borrowings. Adoption of this guidance also impacted the presentation of debt issuance costs related to our discontinued operations. As of 30 September 2016, noncurrent assets and noncurrent liabilities of discontinued operations were both reduced by $9.6 . Definition of a Business In January 2017, the FASB issued guidance that clarifies the definition of a business to assist in determining whether transactions should be accounted for as acquisitions (or disposals) of assets or businesses. Under the new guidance, fewer transactions are expected to be accounted for as business combinations. We elected to early adopt this guidance prospectively beginning in the first quarter of fiscal year 2017. This guidance did not have a significant impact on our consolidated financial statements upon adoption. New Accounting Guidance to be Implemented Revenue Recognition In May 2014, the FASB issued guidance based on the principle that revenue is recognized in an amount expected to be collected and to which the entity expects to be entitled in exchange for the transfer of goods or services. We have the option to adopt the standard in either fiscal year 2018 or 2019, either retrospectively or as a cumulative-effect adjustment as of the date of adoption under the modified retrospective approach. We expect to adopt this guidance in fiscal year 2019 under the modified retrospective approach, which will result in a cumulative-effect adjustment as of 1 October 2018. To date, we have focused on identifying potential impacts on our onsite gases and sale of equipment businesses and on efforts needed to meet the expanded disclosure requirements. Our evaluation of the effect of the new standard will extend over future periods. Leases In February 2016, the FASB issued guidance which requires lessees to recognize a right-of-use asset and lease liability on the balance sheet for all leases, including operating leases, with a term in excess of 12 months. The guidance also expands the quantitative and qualitative disclosure requirements. The guidance is effective in fiscal year 2020, with early adoption permitted, and must be applied using a modified retrospective approach. We are currently evaluating the impact of adopting this new guidance on the consolidated financial statements, including the assessment of our current lease population under the revised definition of what qualifies as a leased asset. The Company is the lessee under various agreements for real estate, distribution equipment, aircraft, and vehicles that are currently accounted for as operating leases as discussed in Note 12 , Leases . The new guidance will require the Company to record operating leases on the balance sheet with a right-of-use asset and corresponding liability for future payment obligations. The Company is currently considered the lessor under certain agreements associated with facilities that are built to provide product to a specific customer. Derivative Contract Novations In March 2016, the FASB issued guidance to clarify that a change in the counterparty to a derivative instrument that has been designated as a hedging instrument does not, in and of itself, require re-designation of that hedging relationship provided that all other hedge accounting criteria continue to be met. This guidance is effective in fiscal year 2018, with early adoption permitted. We do not expect adoption of this guidance to have a significant impact on our consolidated financial statements. Credit Losses on Financial Instruments In June 2016, the FASB issued an update on the measurement of credit losses, which requires measurement and recognition of expected credit losses for financial assets, including trade receivables and capital lease receivables, held at the reporting date based on historical experience, current conditions, and reasonable and supportable forecasts. The method to determine a loss is different from the existing guidance, which requires a credit loss to be recognized when it is probable. The guidance is effective beginning in fiscal year 2021, with early adoption permitted beginning in fiscal year 2020. We are currently evaluating the impact this update will have on our consolidated financial statements. Cash Flow Statement Classification In August 2016, the FASB issued guidance to reduce diversity in practice on how certain cash receipts and cash payments are classified in the statement of cash flows. The guidance is effective beginning fiscal year 2019, with early adoption permitted, and should be applied retrospectively. We are currently evaluating the impact of adopting this new guidance on the consolidated financial statements Intra-Entity Asset Transfers In October 2016, the FASB issued guidance on the accounting for the income tax effects of intra-entity transfers of assets other than inventory. Current GAAP prohibits the recognition of current and deferred income taxes for an intra-entity asset transfer until the asset has been sold to an outside party. Under the new guidance, the income tax consequences of an intra-entity asset transfer are recognized when the transfer occurs. The guidance is effective beginning in fiscal year 2019, with early adoption permitted as of the beginning of an annual reporting period. The guidance must be applied on a modified retrospective basis through a cumulative-effect adjustment directly to retained earnings as of the date of adoption. We are currently evaluating the impact this guidance will have on our consolidated financial statements and plan to adopt the guidance in fiscal year 2019. Derecognition of Nonfinancial Assets In February 2017, the FASB issued an update to clarify the scope of guidance on gains and losses from the derecognition of nonfinancial assets and to add guidance for partial sales of nonfinancial assets. The update must be adopted at the same time as the new guidance on revenue recognition discussed above, which we intend to adopt in fiscal year 2019. The guidance may be applied retrospectively or with a cumulative-effect adjustment to retained earnings at the date of adoption. We are currently evaluating the impact this update will have on our consolidated financial statements. Presentation of Net Periodic Pension and Postretirement Benefit Cost In March 2017, the FASB issued guidance for improving the presentation of net periodic pension cost and net periodic postretirement benefit cost. The amendments require that the service cost component of the net periodic benefit cost be presented in the same line items as other compensation costs arising from services rendered by employees during the period. The other components of net periodic benefit cost (e.g., interest cost, expected return on plan assets, and amortization of actuarial gains/losses) should be presented in the income statement separately from the service cost component and outside of operating income. The amendments also allow only the service cost component to be eligible for capitalization when applicable. The guidance is effective beginning in fiscal year 2019, with early adoption permitted as of the beginning of fiscal year 2018. The amendments should be applied retrospectively for the presentation requirements and prospectively for the capitalization of the service cost component requirements. We expect to early adopt this guidance beginning fiscal year 2018. We currently classify all net periodic pension costs within operating costs, primarily within cost of sales and selling and administrative expense. The line item classification changes required by the new guidance will not impact the Company's pretax earnings or net income; however, operating income and other non-operating income (expense), net will change by offsetting amounts that are not expected to be material to the Company's consolidated financial statements. Hedging Activities In August 2017, the FASB issued guidance on hedging activities to expand the related presentation and disclosure requirements, change how companies assess effectiveness, and eliminate the separate measurement and reporting of hedge ineffectiveness. The guidance also enables more financial and nonfinancial hedging strategies to become eligible for hedge accounting. The guidance is effective in fiscal year 2020, with early adoption permitted. For cash flow and net investment hedges existing at the date of adoption, an entity should apply a cumulative-effect adjustment to eliminate the separate measurement of ineffectiveness within equity as of the beginning of the fiscal year the guidance is adopted. The amended presentation and disclosure guidance is applied prospectively. We are currently evaluating the impact this guidance will have on our consolidated financial statements.

Discontinued Operations

Discontinued Operations	12 Months Ended
	Sep. 30, 2017
Discontinued Operations and Disposal Groups [Abstract]
Discontinued Operations	3 . DISCONTINUED OPERATIONS Materials Technologies On 16 September 2015, we announced plans to separate our Materials Technologies segment, which contained two divisions, the Electronic Materials Division (EMD) and the Performance Materials Division (PMD). As further discussed below, we completed the separation of EMD through the spin-off of Versum Materials, Inc. (Versum) and the sale of PMD to Evonik Industries AG (Evonik) in fiscal year 2017. As a result, these divisions are reflected in our consolidated financial statements as discontinued operations for all periods presented. Spin-off of EMD On 1 October 2016 (the distribution date), Air Products completed the spin-off of Versum into a separate and independent public company. The spin-off was completed by way of a distribution to Air Products’ stockholders of all of the then issued and outstanding shares of common stock of Versum on the basis of one share of Versum common stock for every two shares of Air Products’ common stock held as of the close of business on 21 September 2016 (the record date for the distribution). Fractional shares of Versum common stock were not distributed to Air Products' common stockholders. Air Products’ stockholders received cash in lieu of fractional shares. As a result of the distribution, Versum is now an independent public company, and its common stock is listed under the symbol “VSM” on the New York Stock Exchange. The spin-off of Versum was treated as a noncash transaction in the consolidated statements of cash flows in fiscal year 2017. Sale of PMD On 3 January 2017, we completed the sale of PMD to Evonik for $3.8 billion in cash. A gain of $2,870 ($ 1,828 after‑tax, or $8.32 per share) was recognized on the sale. A portion of the proceeds from the sale have been included in "Short-term investments" on the consolidated balance sheets. Interest income earned on the sale proceeds has been reflected on the consolidated income statements within “Other non-operating income (expense), net." Energy-from-Waste On 29 March 2016, the Board of Directors approved the Company’s exit of its Energy‑from‑Waste (EfW) business and efforts to start up and operate the two EfW projects located in Tees Valley, United Kingdom, were discontinued. Since that time, the EfW segment has been presented as a discontinued operation. During the second quarter of fiscal year 2016, we recorded a loss of $945.7 ( $846.6 after-tax) to write down plant assets to their estimated net realizable value and record a liability for plant disposition and other costs. Income tax benefits related only to one of the projects as the other did not qualify for a local tax deduction. We estimated the net realizable value of the projects assuming an orderly liquidation of assets capable of being marketed on a secondary equipment market based on market quotes and our experience with selling similar equipment. An asset’s orderly liquidation value is the amount that could be realized from a liquidation sale, given a reasonable period of time to find a buyer, selling the asset in the existing condition where it is located, and assuming the highest and best use of the asset by market participants. A valuation allowance of $58.0 and unrecognized tax benefits of $7.9 were recorded relating to deferred tax assets on capital assets generated from the loss. During the first quarter of fiscal year 2017, we determined that it is unlikely for a buyer to assume the remaining assets and contract obligations, including land lease obligations. As a result, we recorded an additional loss of $59.3 ( $47.1 after-tax) in results of discontinued operations, of which $53.0 was recorded primarily for land lease obligations and $6.3 was recorded to update our estimate of the net realizable value of the plant assets as of 31 December 2016. There have been no changes to our estimates during the remainder of fiscal year 2017 . We may incur additional exit costs in future periods related to other outstanding commitments. The following table summarizes the carrying amount of the accrual for our actions to dispose of the EfW business at 30 September 2017 : Asset Actions Contract Actions/ Other Total Loss on disposal of business $ 913.5 $ 32.2 $ 945.7 Noncash expenses (913.5 ) — (913.5 ) Cash expenditures — (18.6 ) (18.6 ) Currency translation adjustment — (1.4 ) (1.4 ) 30 September 2016 $ — $ 12.2 $ 12.2 Loss on disposal of business 6.3 53.0 59.3 Noncash expenses (6.3 ) — (6.3 ) Cash expenditures — (1.4 ) (1.4 ) Currency translation adjustment — 7.3 7.3 Amount reflected in other noncurrent liabilities — (65.3 ) (65.3 ) 30 September 2017 $ — $ 5.8 $ 5.8 The loss on disposal was recorded as a component of discontinued operations. The amount reflected in other noncurrent liabilities primarily relates to land lease obligations and is recorded in continuing operations. The remaining accrual is reflected in current liabilities of discontinued operations. Summarized Financial Information of Discontinued Operations The following tables detail the businesses and major line items that comprise income from discontinued operations, net of tax, on the consolidated income statements: Total Performance Energy-from- Discontinued Year Ended 30 September 2017 Materials Waste (A) Operations Sales $ 254.8 $ — $ 254.8 Cost of sales 182.3 13.8 196.1 Selling and administrative 22.5 .7 23.2 Research and development 5.1 — 5.1 Other income (expense), net .3 (2.0 ) (1.7 ) Operating Income (Loss) 45.2 (16.5 ) 28.7 Equity affiliates’ income .3 — .3 Income (Loss) Before Taxes 45.5 (16.5 ) 29.0 Income tax benefit (B) (50.8 ) (5.7 ) (56.5 ) Income (Loss) From Operations of Discontinued Operations, net of tax 96.3 (10.8 ) 85.5 Gain (Loss) on Disposal, net of tax (C) 1,827.6 (47.1 ) 1,780.5 Income (Loss) From Discontinued Operations, net of tax $ 1,923.9 $ (57.9 ) $ 1,866.0 (A) The loss from operations of discontinued operations for EfW primarily relates to costs incurred for ongoing project exit activities, administrative costs, and land lease obligations. (B) As a result of the expected gain on sale of PMD, we released valuation allowances related to capital loss and net operating loss carryforwards primarily during the first quarter of 2017 that favorably impacted our income tax provision within discontinued operations by approximately $69 . (C) After-tax gain on sale of $1,827.6 includes expense for income tax reserves for uncertain tax positions of $28.0 gross ( $21.0 net) in various jurisdictions. Total Electronic Performance Energy-from- Discontinued Year Ended 30 September 2016 Materials Materials Waste (A) Operations Sales $ 961.6 $ 1,059.1 $ — $ 2,020.7 Cost of sales 521.6 704.5 24.6 1,250.7 Selling and administrative 87.7 76.6 2.8 167.1 Research and development 40.8 19.6 .9 61.3 Other income (expense), net 2.2 4.2 (12.7 ) (6.3 ) Operating Income (Loss) 313.7 262.6 (41.0 ) 535.3 Equity affiliates’ income .2 1.4 — 1.6 Interest expense .3 — — .3 Income (Loss) Before Taxes (B) 313.6 264.0 (41.0 ) 536.6 Income tax provision (benefit) 73.4 80.5 (3.4 ) 150.5 Income (Loss) From Operations of Discontinued Operations, net of tax 240.2 183.5 (37.6 ) 386.1 Loss on Disposal, net of tax — — (846.6 ) (846.6 ) Income (Loss) From Discontinued Operations, net of tax 240.2 183.5 (884.2 ) (460.5 ) Net Income Attributable to Noncontrolling Interests of Discontinued Operations 7.9 — — 7.9 Net Income (Loss) From Discontinued Operations $ 232.3 $ 183.5 $ (884.2 ) $ (468.4 ) (A) The loss from operations of discontinued operations for EfW primarily relates to project suspension costs, land lease obligations, and administrative costs. (B) In fiscal year 2016 , income before taxes from operations of discontinued operations attributable to Air Products was $527.1 . Total Electronic Performance Energy-from- Discontinued Year Ended 30 September 2015 Materials Materials Waste (A) Operations Sales $ 984.1 $ 1,086.5 $ — $ 2,070.6 Cost of sales 586.8 754.0 5.1 1,345.9 Selling and administrative 86.4 79.9 2.4 168.7 Research and development 37.5 23.2 1.7 62.4 Other income (expense), net (B) (18.5 ) (9.2 ) — (27.7 ) Operating Income (Loss) 254.9 220.2 (9.2 ) 465.9 Equity affiliates’ income 1.0 1.2 — 2.2 Interest expense .1 .6 — .7 Income (Loss) Before Taxes (C) 255.8 220.8 (9.2 ) 467.4 Income tax provision (benefit) 49.7 68.4 (2.4 ) 115.7 Income (Loss) From Discontinued Operations, net of tax 206.1 152.4 (6.8 ) 351.7 Net Income Attributable to Noncontrolling Interests of Discontinued Operations 7.1 — — 7.1 Net Income (Loss) From Discontinued Operations $ 199.0 $ 152.4 $ (6.8 ) $ 344.6 (A) The loss from operations of discontinued operations for EfW primarily relates to land lease obligations and administrative costs. (B) Primarily includes business restructuring and cost reduction actions. (C) In fiscal year 2015 , income before taxes from operations of discontinued operations attributable to Air Products was $458.9 . The following tables detail the businesses and major line items that comprise assets and liabilities of discontinued operations on the consolidated balance sheets: Total Performance Energy-from- Discontinued 30 September 2017 Materials Waste Operations Assets Current Assets Plant and equipment, net $ — $ 10.2 $ 10.2 Total Current Assets — 10.2 10.2 Total Assets $ — $ 10.2 $ 10.2 Liabilities Current Liabilities Payables and accrued liabilities $ 9.2 $ 6.5 $ 15.7 Total Current Liabilities 9.2 6.5 15.7 Total Liabilities $ 9.2 $ 6.5 $ 15.7 Total Electronic Performance Energy-from- Discontinued 30 September 2016 Materials Materials Waste Operations Assets Current Assets Cash and cash items $ 170.6 $ 37.5 $ — $ 208.1 Trade receivables, net 134.7 159.0 — 293.7 Inventories 138.1 226.8 — 364.9 Plant and equipment, net — — 18.2 18.2 Other receivables and current assets 34.5 5.6 1.2 41.3 Total Current Assets 477.9 428.9 19.4 926.2 Plant and equipment, net 296.5 296.5 — 593.0 Goodwill, net 180.0 125.0 — 305.0 Intangible assets, net 75.1 25.0 — 100.1 Other noncurrent assets 37.5 6.7 — 44.2 Total Noncurrent Assets 589.1 453.2 — 1,042.3 Total Assets $ 1,067.0 $ 882.1 $ 19.4 $ 1,968.5 Liabilities Current Liabilities Payables and accrued liabilities $ 85.8 $ 72.5 $ 19.0 $ 177.3 Accrued income taxes 22.7 6.0 — 28.7 Current portion of long-term debt 5.8 — — 5.8 Total Current Liabilities 114.3 78.5 19.0 211.8 Long-term debt 981.8 — — 981.8 Deferred income taxes 50.3 6.4 — 56.7 Other noncurrent liabilities 47.4 9.6 — 57.0 Total Noncurrent Liabilities 1,079.5 16.0 — 1,095.5 Total Liabilities $ 1,193.8 $ 94.5 $ 19.0 $ 1,307.3

Materials Technologies Separati

Materials Technologies Separation	12 Months Ended
	Sep. 30, 2017
Restructuring and Related Activities [Abstract]
Materials Technologies Separation	4 . MATERIALS TECHNOLOGIES SEPARATION Business Separation Costs In connection with the disposition of the divisions comprising the former Materials Technologies segment, we incurred separation costs of $30.2 , $50.6 , and $7.5 in 2017 , 2016 , and 2015 , respectively. These costs are reflected on the consolidated income statements as “Business separation costs” and include legal, advisory, and pension related costs. Our fiscal year 2017 income tax provision includes net tax benefits of $5.5 primarily related to changes in tax positions on business separation activities. Our fiscal year 2016 income tax provision includes additional tax expense related to the separation of $51.8 , of which $45.7 resulted from a dividend that was declared in June 2016 to repatriate $443.8 from a subsidiary in South Korea to the U.S. in anticipation of the separation of EMD from the industrial gases business in South Korea. Transition Services Agreements In connection with the spin-off of Versum, we entered into various agreements necessary to effect the spin-off and to govern the ongoing relationships between Air Products and Versum after the separation, including a transition services agreement by which we provide certain transition services to Versum. We expect all transition services to end in 2018. Seifi Ghasemi, chairman, president and chief executive officer of Air Products, is serving as non‑executive chairman of the Versum Board of Directors. In connection with the sale of PMD, we entered into a transition services agreement by which we provide certain transition services to Evonik for no longer than 12 months from the date of sale of 3 January 2017. The reimbursement for costs in support of the transition services agreements with Versum and Evonik has been reflected on the consolidated income statements within “Other income (expense), net.” Loss on Extinguishment of Debt On 30 September 2016, in anticipation of the spin-off, Versum entered into certain financing transactions to allow for a cash distribution of $550.0 and a distribution in-kind of senior unsecured notes (the "Notes") issued by Versum with an aggregate principal amount of $425.0 to Air Products. Air Products then exchanged these Notes with certain financial institutions for $418.3 of Air Products’ outstanding commercial paper. This noncash exchange, which was excluded from the consolidated statements of cash flows, resulted in a loss of $6.9 that has been reflected on the consolidated income statements as “Loss on extinguishment of debt.” This loss was deductible for tax purposes.

Business Restructuring and Cost

Business Restructuring and Cost Reduction Actions	12 Months Ended
	Sep. 30, 2017
Restructuring Charges [Abstract]
Business Restructuring and Cost Reduction Actions	5 . BUSINESS RESTRUCTURING AND COST REDUCTION ACTIONS The charges we record for business restructuring and cost reduction actions have been excluded from segment operating income. Cost Reduction Actions In fiscal year 2017 , we recognized a net expense of $ 151.4 . The year-to-date net expense included a charge of $154.8 for actions taken during fiscal year 2017 , partially offset by the favorable settlement of the remaining $3.4 accrued balance associated with business restructuring actions taken in 2015. Asset actions of $88.5 included charges resulting from the write-down of an air separation unit in the Industrial Gases – EMEA segment that was constructed mainly to provide oxygen to one of the Energy-from-Waste plants, the planned sale of a non-industrial gas hardgoods business in the Industrial Gases – Americas segment, and the closure of a facility in the Corporate and other segment that manufactured liquefied natural gas (LNG) heat exchangers. During fiscal year 2017 , severance and other benefits totaled $66.3 and related to the elimination or planned elimination of approximately 625 positions, primarily in the Corporate and other segment and in the Industrial Gases – EMEA segment. The actions in the Corporate and other segment were driven by the reorganization of our engineering, manufacturing, and technology functions. The 2017 charge related to the segments as follows: $ 39.3 in Industrial Gases – Americas, $ 77.9 in Industrial Gases – EMEA, $ .9 in Industrial Gases – Asia, $ 2.5 in Industrial Gases – Global, and $ 34.2 in Corporate and other. In fiscal year 2016, we recognized an expense of $34.5 for severance and other benefits related to cost reduction actions which resulted in the elimination of approximately 610 positions. The expenses related primarily to the Industrial Gases – Americas segment and the Industrial Gases – EMEA segment. The following table summarizes the carrying amount of the accrual for cost reduction actions at 30 September 2017 : Severance and Other Benefits Asset Actions/Other Total 2016 Charge $ 34.5 $ — $ 34.5 Amount reflected in pension liability (.9 ) — (.9 ) Cash expenditures (21.6 ) — (21.6 ) Currency translation adjustment .3 — .3 30 September 2016 $ 12.3 $ — $ 12.3 2017 Charge 66.3 88.5 154.8 Noncash expenses — (84.2 ) (84.2 ) Amount reflected in pension liability (2.0 ) — (2.0 ) Amount reflected in other noncurrent liabilities — (2.2 ) (2.2 ) Cash expenditures (35.7 ) (1.2 ) (36.9 ) Currency translation adjustment (.3 ) — (.3 ) 30 September 2017 $ 40.6 $ .9 $ 41.5 Business Realignment and Reorganization On 18 September 2014, we announced plans to reorganize the Company, including realignment of our businesses in new reporting segments and other organizational changes, effective as of 1 October 2014. As a result of this reorganization, we incurred severance and other charges. In fiscal year 2015, we recognized an expense of $180.1 . Severance and other benefits totaled $131.5 and related to the elimination of approximately 1,700 positions. Asset and associated contract actions totaled $48.6 and related primarily to a plant shutdown in the Corporate and other segment and the exit of a product line within the Industrial Gases – Global segment. The 2015 charges related to the segments as follows: $31.7 in Industrial Gases – Americas, $52.2 in Industrial Gases – EMEA, $10.3 in Industrial Gases – Asia, $37.0 in Industrial Gases – Global, and $48.9 in Corporate and other. During the fourth quarter of 2014, an expense of $11.1 was incurred relating to the elimination of approximately 40 positions. The following table summarizes the carrying amount of the accrual for the business realignment and reorganization at 30 September 2017: Severance and Other Benefits Asset Actions/Other Total 2014 Charge $ 11.1 $ — $ 11.1 Cash expenditures (1.7 ) — (1.7 ) 30 September 2014 $ 9.4 $ — $ 9.4 2015 Charge 131.5 48.6 180.1 Amount reflected in pension liability (11.2 ) — (11.2 ) Noncash expenses — (40.2 ) (40.2 ) Cash expenditures (100.3 ) (1.2 ) (101.5 ) Currency translation adjustment (.4 ) — (.4 ) 30 September 2015 $ 29.0 $ 7.2 $ 36.2 Cash expenditures (28.6 ) (3.8 ) (32.4 ) Currency translation adjustment (.4 ) — (.4 ) 30 September 2016 $ — $ 3.4 $ 3.4 Accrual settlement — (3.4 ) (3.4 ) 30 September 2017 $ — $ — $ —

Business Combination

Business Combination	12 Months Ended
	Sep. 30, 2017
Business Combinations [Abstract]
Business Combination	6 . BUSINESS COMBINATION On 30 December 2014, we acquired our partner’s equity ownership interest in a liquefied atmospheric industrial gases production joint venture in North America for $22.6 , which increased our ownership from 50% to 100% . The transaction was accounted for as a business combination, and subsequent to the acquisition, the results are consolidated within our Industrial Gases – Americas segment. The assets acquired, primarily plant and equipment, were recorded at their fair market values as of the acquisition date. The acquisition date fair value of the previously held equity interest was determined using a discounted cash flow analysis under the income approach. The twelve months ended 30 September 2015 include a gain of $17.9 as a result of revaluing our previously held equity interest to fair value as of the acquisition date. This gain is reflected on the consolidated income statements as “Gain on previously held equity interest.”

Inventories

Inventories	12 Months Ended
	Sep. 30, 2017
Inventory Disclosure [Abstract]
Inventories	7 . INVENTORIES The components of inventories are as follows: 30 September 2017 2016 Finished goods $ 120.0 $ 131.3 Work in process 15.7 18.3 Raw materials, supplies and other 223.0 117.1 Total FIFO Cost 358.7 266.7 Less: Excess of FIFO cost over LIFO cost (23.3 ) (11.7 ) Inventories $ 335.4 $ 255.0 Inventories valued using the LIFO method comprised 48.7% and 22.9% of consolidated inventories before LIFO adjustment at 30 September 2017 and 2016 , respectively. Liquidation of LIFO inventory layers in 2017 , 2016 , and 2015 did not materially affect the results of operations. FIFO cost approximates replacement cost.

Summarized Financial Informatio

Summarized Financial Information of Equity Affiliates	12 Months Ended
	Sep. 30, 2017
Equity Method Investments and Joint Ventures [Abstract]
Summarized Financial Information of Equity Affiliates	8 . SUMMARIZED FINANCIAL INFORMATION OF EQUITY AFFILIATES The summarized financial information below is on a combined 100% basis and has been compiled based on financial statements of the companies accounted for by the equity method. The amounts presented include the accounts of the following equity affiliates: Abdullah Hashim Industrial Gases & Equipment Co., Ltd. (25%); INOX Air Products Limited (50%); Air Products South Africa (Proprietary) Limited (50%); Jazan Gas Projects Company (25%); Bangkok Cogeneration Company Limited (49%); Kulim Industrial Gases Sdn. Bhd. (50%); Bangkok Industrial Gases Co., Ltd. (49%); Sapio Produzione Idrogeno Ossigeno S.r.l. (49%); Chengdu Air & Gas Products Ltd. (50%); Tecnologia en Nitrogeno S. de R.L. de C.V. (50%); Helios S.p.A. (49%); Tyczka Industrie-Gases GmbH (50%); High-Tech Gases (Beijing) Co., Ltd. (50%); WuXi Hi-Tech Gas Co., Ltd. (50%); INFRA Group (40%); and principally, other industrial gas producers. 30 September 2017 2016 Current assets $ 1,333.2 $ 1,436.7 Noncurrent assets 4,026.9 3,063.3 Current liabilities 666.8 694.8 Noncurrent liabilities 2,194.3 1,540.4 Year Ended 30 September 2017 2016 2015 Net sales $ 2,343.3 $ 2,271.6 $ 2,460.5 Sales less cost of sales 878.6 871.5 922.7 Operating income 509.5 482.1 512.4 Net income 343.5 334.1 343.5 The increase in noncurrent assets and noncurrent liabilities is primarily related to Jazan Gas Projects Company. Dividends received from equity affiliates were $99.5 , $95.9 , and $50.5 in 2017 , 2016 , and 2015 , respectively. The investment in net assets of and advances to equity affiliates as of 30 September 2017 and 2016 included investment in foreign affiliates of $1,285.1 and $1,281.5 , respectively. As of 30 September 2017 and 2016 , the amount of investment in companies accounted for by the equity method included equity method goodwill in the amount of $45.8 and $109.5 , respectively. The decrease was primarily driven by an other-than-temporary impairment of our investment in an equity affiliate in Saudi Arabia discussed below. Equity Affiliate Impairment Charge During the third quarter of fiscal year 2017, Abdullah Hashim Industrial Gases & Equipment Co., Ltd. (AHG), a 25% ‑owned equity affiliate in our Industrial Gases – EMEA segment, completed a review of its business plan and outlook. As a result of the revised business plan, we determined there was an other-than-temporary impairment of our investment in AHG and, therefore, recorded a noncash impairment charge of $79.5 to reduce the carrying value of our investment. This charge is reflected on our consolidated income statements within “Equity affiliates' income” and was not deductible for tax purposes. This charge has been excluded from segment results. The decline in value results from expectations for lower future cash flows to be generated by AHG, primarily due to challenging economic conditions in Saudi Arabia, including the impacts of lower prices in the oil and gas industry, increased competition, and capital project growth opportunities not materializing as anticipated. The AHG investment was valued based on the results of the income and market valuation approaches. The income approach utilized a discount rate based on a market-participant, risk-adjusted weighted average cost of capital, which considers industry required rates of return on debt and equity capital for a target industry capital structure adjusted for risks associated with size and geography. Other significant estimates and assumptions that drive our updated valuation of AHG include revenue growth rates and profit margins that were lower than those upon acquisition and our assessment of AHG's business improvement plan effectiveness. Under the market approach, we estimated fair value based on market multiples of revenue and earnings derived from publicly-traded industrial gases companies engaged in similar lines of business, adjusted to reflect differences in size and growth prospects. As of 30 September 2017 , the carrying value of our investment in AHG is $66.7 and is reflected in our Industrial Gases – EMEA segment. The investment is reported in “Investment in net assets of and advances to equity affiliates” on our consolidated balance sheets. There have been no other significant changes to our investments in equity affiliates during fiscal year 2017 . Jazan On 19 April 2015, a joint venture between Air Products and ACWA Holding entered into a 20 -year oxygen and nitrogen supply agreement to supply Saudi Aramco’s oil refinery and power plant being built in Jazan, Saudi Arabia. Air Products owns 25% of the joint venture and guarantees the repayment of its share of an equity bridge loan. ACWA also guarantees their share of the loan. We determined that the joint venture is a variable interest entity, for which we are not the primary beneficiary. As of 30 September 2017 and 2016 , other noncurrent liabilities included $94.4 for our obligation to make future equity contributions based on our proportionate share of the advances received by the joint venture under the loan. During fiscal year 2016 and 2015, we recorded noncash transactions that resulted in an increase of $26.9 and $67.5 , respectively, to our investment in net assets of and advances to equity affiliates. These noncash transactions have been excluded from the consolidated statement of cash flows. In total, we expect to invest approximately $100 in this joint venture. There has been no change to our investment during fiscal year 2017 . Air Products has a long-term sale of equipment contract with the joint venture to engineer, procure, and construct the industrial gas facilities that will supply the gases to Saudi Aramco. Sales related to this contract are included in the results of our Industrial Gases – Global segment and were approximately $540 and $300 during fiscal year 2017 and 2016 , respectively. Sales related to this contract were not material during fiscal year 2015 .

Plant and Equipment, Net

Plant and Equipment, Net	12 Months Ended
	Sep. 30, 2017
Property, Plant and Equipment [Abstract]
Plant and Equipment, Net	9 . PLANT AND EQUIPMENT, NET The major classes of plant and equipment are as follows: 30 September Useful Life in years 2017 2016 Land $ 231.0 $ 202.9 Buildings 30 977.8 918.6 Production facilities (A) 10 to 20 13,577.1 12,391.9 Distribution and other machinery and equipment (B) 5 to 25 3,944.0 3,821.0 Construction in progress 817.9 1,325.8 Plant and equipment, at cost 19,547.8 18,660.2 Less: accumulated depreciation 11,107.6 10,400.5 Plant and equipment, net $ 8,440.2 $ 8,259.7 (A) Depreciable lives of production facilities related to long-term customer supply contracts are matched to the contract lives. (B) The depreciable lives for various types of distribution equipment are 10 to 25 years for cylinders, depending on the nature and properties of the product; 20 years for tanks; 7.5 years for customer stations; and 5 to 15 years for tractors and trailers. Depreciation expense was $843.2 , $832.3 , and $834.5 in 2017 , 2016 , and 2015 , respectively.

Goodwill

Goodwill	12 Months Ended
	Sep. 30, 2017
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill	10 . GOODWILL Changes to the carrying amount of consolidated goodwill by segment are as follows: Industrial Gases– Americas Industrial Gases– EMEA Industrial Gases– Asia Industrial Gases– Global Total Goodwill, net at 30 September 2015 $ 297.6 $ 386.5 $ 133.1 $ 19.9 $ 837.1 Currency translation 11.5 (5.9 ) 2.1 .3 8.0 Goodwill, net at 30 September 2016 $ 309.1 $ 380.6 $ 135.2 $ 20.2 $ 845.1 Impairment loss (145.3 ) — — — (145.3 ) Acquisitions — 3.5 — — 3.5 Currency translation (.1 ) 18.3 — — 18.2 Goodwill, net at 30 September 2017 $ 163.7 $ 402.4 $ 135.2 $ 20.2 $ 721.5 30 September 2017 2016 2015 Goodwill, gross $ 1,138.7 $ 1,103.7 $ 1,080.8 Accumulated impairment losses (417.2 ) (258.6 ) (243.7 ) Goodwill, net $ 721.5 $ 845.1 $ 837.1 We review goodwill for impairment annually in the fourth quarter of the fiscal year and whenever events or changes in circumstances indicate that the carrying value of goodwill might not be recoverable. As described in Note 2 , New Accounting Guidance , we elected to early adopt new accounting guidance that simplifies the test for goodwill impairment during the third quarter of fiscal year 2017. For the first nine months of fiscal year 2017, volumes declined in our Latin America reporting unit (LASA), and overall revenue growth did not meet expectations. Due to weak economic conditions in Latin America and expectations for continued volume weakness in the Latin American countries and markets in which we operate, we lowered our long-term growth projections. We conducted an interim impairment test of the goodwill associated with LASA within the Industrial Gases – Americas segment as of 30 June 2017. As a result, we recorded a noncash goodwill impairment charge of $145.3 , which has been reflected on our consolidated income statements within “Goodwill and intangible asset impairment charge.” This charge was not deductible for tax purposes and has been excluded from segment operating income. LASA includes assets and goodwill associated with operations in Chile and other Latin American countries. We estimated the fair value of LASA based on two valuation approaches, the income approach and the market approach. We reviewed relevant facts and circumstances in determining the weighting of the approaches. Under the income approach, we estimated the fair value of LASA based on the present value of estimated future cash flows. Cash flow projections were based on management’s estimates of revenue growth rates and EBITDA margins, taking into consideration business and market conditions for the Latin American countries and markets in which we operate. We calculated the discount rate based on a market-participant, risk-adjusted weighted average cost of capital, which considers industry‑specific rates of return on debt and equity capital for a target industry capital structure, adjusted for risks associated with business size and geography. Under the market approach, we estimated fair value based on market multiples of revenue and earnings derived from publicly-traded industrial gases companies and regional manufacturing companies, adjusted to reflect differences in size and growth prospects. Management judgment is required in the determination of each assumption utilized in the valuation model, and actual results could differ from our estimates. The accumulated impairment losses of $417.2 as of 30 September 2017 are attributable to LASA within the Industrial Gases– Americas segment and include the LASA impairment charge recorded in fiscal year 2014 as well as the impacts of currency translation on the losses. Prior to completing the LASA goodwill impairment test, we tested the recoverability of LASA’s long-lived assets and other indefinite-lived intangible assets. Refer to Note 11 , Intangible Assets , for additional information. During the fourth quarter of 2017 , we conducted our annual goodwill impairment test. We determined that the fair value of all our reporting units exceeded their carrying value except LASA, for which the fair value equaled the carrying value.

Intangible Assets

Intangible Assets	12 Months Ended
	Sep. 30, 2017
Goodwill and Intangible Assets Disclosure [Abstract]
Intangible Assets	11 . INTANGIBLE ASSETS The table below provides details of acquired intangible assets: 30 September 2017 30 September 2016 Gross Accumulated Amortization/ Impairment Net Gross Accumulated Amortization/ Impairment Net Customer relationships $ 424.1 $ (142.3 ) $ 281.8 $ 400.6 $ (118.2 ) $ 282.4 Patents and technology 13.4 (10.6 ) 2.8 13.6 (10.1 ) 3.5 Other 73.4 (36.6 ) 36.8 73.0 (33.7 ) 39.3 Total finite-lived intangibles 510.9 (189.5 ) 321.4 487.2 (162.0 ) 325.2 Trade names and trademarks, indefinite-lived 67.8 (20.9 ) 46.9 66.2 (3.5 ) 62.7 Total Intangible Assets $ 578.7 $ (210.4 ) $ 368.3 $ 553.4 $ (165.5 ) $ 387.9 The decrease in net intangible assets from 2016 to 2017 is primarily due to amortization and an impairment charge recorded during the third quarter of fiscal year 2017. Amortization expense for intangible assets was $22.6 , $22.3 , and $24.0 in 2017 , 2016 , and 2015 , respectively. Refer to Note 1 , Major Accounting Policies , for amortization periods associated with our intangible assets. Indefinite-lived intangible assets are subject to impairment testing at least annually or more frequently if events or changes in circumstances indicate that potential impairment exists. The impairment test for indefinite-lived intangible assets involves calculating the fair value of the indefinite-lived intangible assets and comparing the fair value to their carrying value. If the fair value is less than the carrying value, the difference is recorded as an impairment loss. As discussed in Note 10 , Goodwill , in response to weak Latin America economic conditions and expectations for continued volume weakness in the Latin American countries and markets in which we operate, we lowered our long-term growth projections. An interim impairment test of indefinite-lived intangibles associated with LASA was conducted as of 30 June 2017 utilizing the royalty savings method, a form of the income approach. We determined that the carrying value of trade names and trademarks was in excess of fair value, and as a result, we recorded a noncash impairment charge of $16.8 to reduce these indefinite-lived intangible assets to their fair value. This charge is reflected within “ Goodwill and intangible asset impairment charge ” on our consolidated income statements. These trade names and trademarks are included in our Industrial Gases – Americas segment. This charge has been excluded from segment operating income. We tested the recoverability of LASA long-lived assets, including finite-lived intangible assets subject to amortization, and concluded that they were recoverable from expected future undiscounted cash flows. In the fourth quarter of 2017 , we conducted our annual impairment test of indefinite-lived intangibles and found no indications of impairment. Projected annual amortization expense for intangible assets as of 30 September 2017 is as follows: 2018 $ 22.1 2019 21.8 2020 21.6 2021 20.1 2022 17.4 Thereafter 218.4 Total $ 321.4

Leases

Leases	12 Months Ended
	Sep. 30, 2017
Leases [Abstract]
Leases	12 . LEASES Lessee Accounting Capital leases, primarily for the right to use machinery and equipment, are included with owned plant and equipment on the consolidated balance sheet in the amount of $22.3 and $22.4 at 30 September 2017 and 2016 , respectively. Related amounts of accumulated depreciation are $5.3 and $4.5 , respectively. Operating leases principally relate to real estate and also include aircraft, distribution equipment, and vehicles. Certain leases include escalation clauses, renewal, and/or purchase options. Rent expense is recognized on a straight-line basis over the minimum lease term. Rent expense under operating leases, including month-to-month agreements, was $65.8 in 2017 , $67.6 in 2016 , and $70.4 in 2015 . At 30 September 2017 , minimum payments due under leases associated with continuing operations are as follows: Capital Leases Operating Leases 2018 $ 2.2 $ 56.6 2019 1.8 45.8 2020 1.6 35.2 2021 3.0 27.1 2022 1.5 22.9 Thereafter 19.9 126.6 Total $ 30.0 $ 314.2 The present value of the above future capital lease payments totaled $10.8 . Refer to Note 15 , Debt . Included in the operating lease payments disclosed above are future minimum payments due under leases related to the Energy-from-Waste discontinued operations (i.e., Tees Valley, United Kingdom ) of approximately $2 in each of the next five years and $40 thereafter, for a total lease commitment of approximately $50 . As discussed in Note 3, Discontinued Operations, during the first quarter of 2017, we recorded an accrual for these lease obligations to other noncurrent liabilities in continuing operations. Lessor Accounting As discussed under Revenue Recognition in Note 1 , Major Accounting Policies , certain contracts associated with facilities that are built to provide product to a specific customer are required to be accounted for as leases. Lease receivables, net, are primarily included in noncurrent capital lease receivables on our consolidated balance sheets, with the remaining balance in other receivables and current assets. The components of lease receivables were as follows: 30 September 2017 2016 Gross minimum lease payments receivable $ 1,897.0 $ 2,072.6 Unearned interest income (671.9 ) (762.7 ) Lease Receivables, net $ 1,225.1 $ 1,309.9 Lease payments collected in 2017 , 2016 , and 2015 were $183.6 , $186.0 , and $146.6 , respectively. These payments reduced the lease receivable balance by $92.2 , $85.5 , and $68.8 in 2017 , 2016 , and 2015 , respectively. At 30 September 2017 , minimum lease payments expected to be collected are as follows: 2018 $ 182.0 2019 176.4 2020 171.4 2021 165.5 2022 154.1 Thereafter 1,047.6 Total $ 1,897.0

Financial Instruments

Financial Instruments	12 Months Ended
	Sep. 30, 2017
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Financial Instruments	13 . FINANCIAL INSTRUMENTS Currency Price Risk Management Our earnings, cash flows, and financial position are exposed to foreign currency risk from foreign currency-denominated transactions and net investments in foreign operations. It is our policy to minimize our cash flow volatility from changes in currency exchange rates. This is accomplished by identifying and evaluating the risk that our cash flows will change in value due to changes in exchange rates and by executing the appropriate strategies necessary to manage such exposures. Our objective is to maintain economically balanced currency risk management strategies that provide adequate downside protection. Forward Exchange Contracts We enter into forward exchange contracts to reduce the cash flow exposure to foreign currency fluctuations associated with highly anticipated cash flows and certain firm commitments, such as the purchase of plant and equipment. We also enter into forward exchange contracts to hedge the cash flow exposure on intercompany loans. This portfolio of forward exchange contracts consists primarily of Euros and U.S. Dollars. The maximum remaining term of any forward exchange contract currently outstanding and designated as a cash flow hedge at 30 September 2017 is 1.8 years . Forward exchange contracts are also used to hedge the value of investments in certain foreign subsidiaries and affiliates by creating a liability in a currency in which we have a net equity position. The primary currency pair in this portfolio of forward exchange contracts is Euros and U.S. Dollars. In addition to the forward exchange contracts that are designated as hedges, we utilize forward exchange contracts that are not designated as hedges. These contracts are used to economically hedge foreign currency-denominated monetary assets and liabilities, primarily working capital. The primary objective of these forward exchange contracts is to protect the value of foreign currency-denominated monetary assets and liabilities from the effects of volatility in foreign exchange rates that might occur prior to their receipt or settlement. This portfolio of forward exchange contracts consists of many different foreign currency pairs, with a profile that changes from time to time depending on business activity and sourcing decisions. The table below summarizes our outstanding currency price risk management instruments: 30 September 2017 30 September 2016 US$ Notional Years Average Maturity US$ Notional Years Average Maturity Forward Exchange Contracts Cash flow hedges $ 3,150.2 .4 $ 4,130.3 .5 Net investment hedges 675.5 3.0 968.2 2.7 Not designated 273.8 .1 2,648.3 .4 Total Forward Exchange Contracts $ 4,099.5 .8 $ 7,746.8 .7 The notional value of forward exchange contracts not designated in the table above includes forward contracts which were hedging intercompany loans that were repaid prior to their original maturity dates in anticipation of the spin-off of Versum. The forward exchange contracts no longer qualified as cash flow hedges due to the early repayment of the loans. We entered into additional forward exchange contracts to offset these outstanding positions to eliminate any future earnings impact. The decrease in notional value from 30 September 2016 to 30 September 2017 is primarily due to the maturity of the aforementioned intercompany loan hedges and their offsetting positions. In addition to the above, we use foreign currency-denominated debt to hedge the foreign currency exposures of our net investment in certain foreign subsidiaries. The designated foreign currency-denominated debt and related accrued interest included €912.2 million ( $1,077.7 ) at 30 September 2017 and €920.7 million ( $1,034.4 ) at 30 September 2016 . The designated foreign currency-denominated debt is located on the balance sheet in the long-term debt line item. Debt Portfolio Management It is our policy to identify on a continuing basis the need for debt capital and evaluate the financial risks inherent in funding the Company with debt capital. Reflecting the result of this ongoing review, the debt portfolio and hedging program are managed with the objectives and intent to (1) reduce funding risk with respect to borrowings made by us to preserve our access to debt capital and provide debt capital as required for funding and liquidity purposes, and (2) manage the aggregate interest rate risk and the debt portfolio in accordance with certain debt management parameters. Interest Rate Management Contracts We enter into interest rate swaps to change the fixed/variable interest rate mix of our debt portfolio in order to maintain the percentage of fixed- and variable-rate debt within the parameters set by management. In accordance with these parameters, the agreements are used to manage interest rate risks and costs inherent in our debt portfolio. Our interest rate management portfolio generally consists of fixed-to-floating interest rate swaps (which are designated as fair value hedges), pre-issuance interest rate swaps and treasury locks (which hedge the interest rate risk associated with anticipated fixed-rate debt issuances and are designated as cash flow hedges), and floating-to-fixed interest rate swaps (which are designated as cash flow hedges). At 30 September 2017 , the outstanding interest rate swaps were denominated in U.S. Dollars. The notional amount of the interest rate swap agreements is equal to or less than the designated debt being hedged. When interest rate swaps are used to hedge variable-rate debt, the indices of the swaps and the debt to which they are designated are the same. It is our policy not to enter into any interest rate management contracts which lever a move in interest rates on a greater than one-to-one basis. Cross Currency Interest Rate Swap Contracts We enter into cross currency interest rate swap contracts when our risk management function deems necessary. These contracts may entail both the exchange of fixed- and floating-rate interest payments periodically over the life of the agreement and the exchange of one currency for another currency at inception and at a specified future date. The contracts are used to hedge either certain net investments in foreign operations or nonfunctional currency cash flows related to intercompany loans. The current cross currency interest rate swap portfolio consists of fixed-to-fixed swaps primarily between U.S. Dollars and offshore Chinese Renminbi, U.S. Dollars and Chilean Pesos, and U.S. Dollars and British Pound Sterling. The following table summarizes our outstanding interest rate management contracts and cross currency interest rate swaps: 30 September 2017 30 September 2016 US$ Notional Average Pay % Average Receive % Years Average Maturity US$ Notional Average Pay % Average Receive % Years Average Maturity Interest rate swaps (fair value hedge) $ 600.0 LIBOR 2.28 % 1.3 $ 600.0 LIBOR 2.28 % 2.3 Cross currency interest rate swaps (net investment hedge) $ 539.7 3.27 % 2.59 % 1.9 $ 517.7 3.24 % 2.43 % 2.6 Cross currency interest rate swaps (cash flow hedge) $ 1,095.7 4.96 % 2.78 % 2.4 $ 1,088.9 4.77 % 2.72 % 3.3 Cross currency interest rate swaps (not designated) $ 41.6 3.28 % 2.32 % 1.7 $ 27.4 3.62 % .81 % 1.8 The table below summarizes the fair value and balance sheet location of our outstanding derivatives: Balance Sheet 30 September Balance Sheet 30 September Location 2017 2016 Location 2017 2016 Derivatives Designated as Hedging Instruments: Forward exchange contracts Other receivables $ 81.7 $ 72.3 Accrued liabilities $ 82.0 $ 44.0 Interest rate management contracts Other receivables 11.1 19.9 Accrued liabilities 10.7 — Forward exchange contracts Other noncurrent assets 27.1 44.4 Other noncurrent liabilities 13.8 9.1 Interest rate management contracts Other noncurrent assets 102.6 160.0 Other noncurrent 22.2 12.0 Total Derivatives Designated as Hedging Instruments $ 222.5 $ 296.6 $ 128.7 $ 65.1 Derivatives Not Designated as Hedging Instruments: Forward exchange contracts Other receivables 1.1 77.1 Accrued liabilities $ 2.2 $ 29.5 Interest rate management contracts Other receivables — — Accrued liabilities 1.0 — Interest rate management contracts Other noncurrent assets 4.2 — Other noncurrent — .7 Total Derivatives Not Designated as Hedging Instruments $ 5.3 $ 77.1 $ 3.2 $ 30.2 Total Derivatives $ 227.8 $ 373.7 $ 131.9 $ 95.3 Refer to Note 14 , Fair Value Measurements , which defines fair value, describes the method for measuring fair value, and provides additional disclosures regarding fair value measurements. The table below summarizes the gain or loss related to our cash flow hedges, fair value hedges, net investment hedges, and derivatives not designated as hedging instruments: Year Ended 30 September Forward Exchange Contracts Foreign Currency Debt Other (A) Total 2017 2016 2017 2016 2017 2016 2017 2016 Cash Flow Hedges, net of tax: Net gain (loss) recognized in OCI (effective portion) $ .3 $ 10.5 $ — $ — $ (12.9 ) $ 3.2 $ (12.6 ) $ 13.7 Net (gain) loss reclassified from OCI to sales/cost of sales (effective portion) 18.3 .2 — — — — 18.3 .2 Net (gain) loss reclassified from OCI to other income (expense), net (effective portion) (3.8 ) (25.7 ) — — 10.5 (20.3 ) 6.7 (46.0 ) Net (gain) loss reclassified from OCI to interest expense (effective portion) (2.1 ) 6.7 — — 2.9 3.3 .8 10.0 Net (gain) loss reclassified from OCI to other income (expense), net (ineffective portion) (1.6 ) (.2 ) — — — — (1.6 ) (.2 ) Fair Value Hedges: Net gain (loss) recognized in interest expense (B) $ — $ — $ — $ — $ (14.7 ) $ (8.8 ) $ (14.7 ) $ (8.8 ) Net Investment Hedges, net of tax: Net gain (loss) recognized in OCI $ (11.1 ) $ 17.4 $ (32.8 ) $ (9.6 ) $ (15.6 ) $ 35.0 $ (59.5 ) $ 42.8 Derivatives Not Designated as Hedging Instruments: Net gain (loss) recognized in other income (expense), net (C) $ 4.1 $ (1.8 ) $ — $ — $ (2.4 ) $ (1.6 ) $ 1.7 $ (3.4 ) (A) Other includes the impact on other comprehensive income (OCI) and earnings primarily related to interest rate and cross currency interest rate swaps. (B) The impact of fair value hedges noted above was largely offset by recognized gains and losses resulting from the impact of changes in related interest rates on outstanding debt. (C) The impact of the non-designated hedges noted above was largely offset by recognized gains and losses resulting from the impact of changes in exchange rates on assets and liabilities denominated in nonfunctional currencies. The amount of cash flow hedges’ unrealized gains and losses at 30 September 2017 that are expected to be reclassified to earnings in the next twelve months is not material. The cash flows related to all derivative contracts are reported in the operating activities section of the consolidated statements of cash flows. Credit Risk-Related Contingent Features Certain derivative instruments are executed under agreements that require us to maintain a minimum credit rating with both Standard & Poor’s and Moody’s. If our credit rating falls below this threshold, the counterparty to the derivative instruments has the right to request full collateralization on the derivatives’ net liability position. The net liability position of derivatives with credit risk-related contingent features was $34.6 as of 30 September 2017 and $11.2 as of 30 September 2016 . Because our current credit rating is above the various pre-established thresholds, no collateral has been posted on these liability positions. Counterparty Credit Risk Management We execute financial derivative transactions with counterparties that are highly rated financial institutions, all of which are investment grade at this time. Some of our underlying derivative agreements give us the right to require the institution to post collateral if its credit rating falls below the pre-established thresholds with Standard & Poor’s or Moody’s. The collateral that the counterparties would be required to post was $138.5 as of 30 September 2017 and $267.6 as of 30 September 2016 . No financial institution is required to post collateral at this time, as all have credit ratings at or above the threshold.

Fair Value Measurements

Fair Value Measurements	12 Months Ended
	Sep. 30, 2017
Fair Value Disclosures [Abstract]
Fair Value Measurements	14 . FAIR VALUE MEASUREMENTS Fair value is defined as an exit price, i.e., the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date. The fair value hierarchy prioritizes the inputs to valuation techniques used to measure fair value into three broad levels as follows: Level 1— Quoted prices (unadjusted) in active markets for identical assets or liabilities. Level 2— Inputs that are observable for the asset or liability, either directly or indirectly through market corroboration, for substantially the full term of the asset or liability. Level 3— Inputs that are unobservable for the asset or liability based on our own assumptions (about the assumptions market participants would use in pricing the asset or liability). The methods and assumptions used to measure the fair value of financial instruments are as follows: Short-term Investments Short-term investments include time deposits with original maturities greater than three months and less than one year. The estimated fair value of the short-term investments, which approximates carrying value as of 30 September 2017 and 2016 , was determined using level 2 inputs within the fair value hierarchy. Level 2 measurements were based on current interest rates for similar investments with comparable credit risk and time to maturity. Derivatives The fair value of our interest rate management contracts and forward exchange contracts are quantified using the income approach and are based on estimates using standard pricing models. These models take into account the value of future cash flows as of the balance sheet date, discounted to a present value using discount factors that match both the time to maturity and currency of the underlying instruments. The computation of the fair values of these instruments is generally performed by the Company. These standard pricing models utilize inputs which are derived from or corroborated by observable market data such as interest rate yield curves as well as currency spot and forward rates. Therefore, the fair value of our derivatives is classified as a level 2 measurement. On an ongoing basis, we randomly test a subset of our valuations against valuations received from the transaction’s counterparty to validate the accuracy of our standard pricing models. Counterparties to these derivative contracts are highly rated financial institutions. Refer to Note 13 , Financial Instruments , for a description of derivative instruments, including details on the balance sheet line classifications. Long-term Debt The fair value of our debt is based on estimates using standard pricing models that take into account the value of future cash flows as of the balance sheet date, discounted to a present value using discount factors that match both the time to maturity and currency of the underlying instruments. These standard valuation models utilize observable market data such as interest rate yield curves and currency spot rates. Therefore, the fair value of our debt is classified as a level 2 measurement. We generally perform the computation of the fair value of these instruments. The carrying values and fair values of financial instruments were as follows: 30 September 2017 30 September 2016 Carrying Value Fair Value Carrying Value Fair Value Assets Derivatives Forward exchange contracts $ 109.9 $ 109.9 $ 193.8 $ 193.8 Interest rate management contracts 117.9 117.9 179.9 179.9 Liabilities Derivatives Forward exchange contracts $ 98.0 $ 98.0 $ 82.6 $ 82.6 Interest rate management contracts 33.9 33.9 12.7 12.7 Long-term debt, including current portion 3,818.8 3,928.2 4,275.1 4,474.0 The carrying amounts reported in the balance sheet for cash and cash items, short-term investments, trade receivables, payables and accrued liabilities, accrued income taxes, and short-term borrowings approximate fair value due to the short-term nature of these instruments. Accordingly, these items have been excluded from the above table. The following table summarizes assets and liabilities measured at fair value on a recurring basis in the consolidated balance sheets: 30 September 2017 30 September 2016 Total Level 1 Level 2 Level 3 Total Level 1 Level 2 Level 3 Assets at Fair Value Derivatives Forward exchange contracts $ 109.9 $ — $ 109.9 $ — $ 193.8 $ — $ 193.8 $ — Interest rate management contracts 117.9 — 117.9 — 179.9 — 179.9 — Total Assets at Fair Value $ 227.8 $ — $ 227.8 $ — $ 373.7 $ — $ 373.7 $ — Liabilities at Fair Value Derivatives Forward exchange contracts $ 98.0 $ — $ 98.0 $ — $ 82.6 $ — $ 82.6 $ — Interest rate management contracts 33.9 — 33.9 — 12.7 — 12.7 — Total Liabilities at Fair Value $ 131.9 $ — $ 131.9 $ — $ 95.3 $ — $ 95.3 $ — The following is a tabular presentation of nonrecurring fair value measurements along with the level within the fair value hierarchy in which the fair value measurement in its entirety falls: 31 December 2016 Total Level 1 Level 2 Level 3 2017 Loss 2016 Loss Plant and Equipment – Continuing operations (A) $ 1.4 $ — $ — $ 1.4 $ 45.7 $ — Plant and Equipment—Discontinued operations (A) $ 11.0 $ — $ — $ 11.0 $ 6.3 $ 913.5 (A) We assessed the recoverability of the carrying value of assets associated with the EfW discontinued operation, including the air separation unit within continuing operations of our Industrial Gases – EMEA segment. We based our estimates primarily on an orderly liquidation valuation which resulted in losses for the difference between the orderly liquidation value and net book value of the assets as of 31 December 2016 during fiscal year 2017. There have been no significant updates to our estimates as of 30 September 2017 . For additional information, see Note 3 , Discontinued Operations , and Note 5 , Business Restructuring and Cost Reduction Actions . 30 June 2017 2017 Loss Total Level 1 Level 2 Level 3 Investment in Equity Affiliate (A) $ 68.5 $ — $ — $ 68.5 $ 79.5 (A) We assessed the recoverability of the carrying value of our equity investment in AHG. We estimated the fair value of our investment using weighting of the results of the income and market approaches. An impairment loss was recognized for the difference between the carrying amount and the fair value of the investment as of 30 June 2017. There have been no updates to our estimates as of 30 September 2017 . For additional information, see Note 8 , Summarized Financial Information of Equity Affiliates . During the third quarter ended 30 June 2017, we recognized a goodwill impairment charge of $145.3 and an intangible asset impairment charge of $16.8 associated with our LASA reporting unit. Refer to Note 10 , Goodwill , and Note 11 , Intangible Assets , for more information related to these charges and the associated fair value measurement methods and significant inputs/assumptions, which were classified as Level 3 since unobservable inputs were utilized in the fair value measurements.

Debt

Debt	12 Months Ended
	Sep. 30, 2017
Debt Disclosure [Abstract]
Debt	15 . DEBT The tables below summarize our outstanding debt at 30 September 2017 and 2016 : Total Debt 30 September 2017 2016 Short-term borrowings $ 144.0 $ 935.8 Current portion of long-term debt 416.4 365.4 Long-term debt 3,402.4 3,909.7 Total Debt $ 3,962.8 $ 5,210.9 Short-term Borrowings 30 September 2017 2016 Bank obligations $ 144.0 $ 133.1 Commercial paper — 802.7 Total Short-term Borrowings $ 144.0 $ 935.8 The weighted average interest rate of short-term borrowings outstanding at 30 September 2017 and 2016 was 4.6% and 1.1% , respectively. Cash paid for interest, net of amounts capitalized, was $125.9 in 2017 , $120.6 in 2016 , and $96.8 in 2015 . Long-term Debt 30 September Fiscal Year Maturities 2017 2016 Payable in U.S. Dollars Debentures 8.75% 2021 $ 18.4 $ 18.4 Medium-term Notes (weighted average rate) Series E 7.6% 2026 17.2 17.2 Senior Notes Note 1.2% 2018 400.0 400.0 Note 4.375% 2019 400.0 400.0 Note 3.0% 2022 400.0 400.0 Note 2.75% 2023 400.0 400.0 Note 3.35% 2024 400.0 400.0 Other (weighted average rate) Variable-rate industrial revenue bonds .87% 2035 to 2050 631.9 769.9 Other .89% 2018 to 2019 10.9 25.7 Payable in Other Currencies Eurobonds 4.625% 2017 — 337.0 Eurobonds 2.0% 2020 354.4 337.0 Eurobonds 1.0% 2025 354.4 337.0 Eurobonds .375% 2021 413.5 393.2 Other 4.3% 2018 to 2022 25.8 52.9 Capital Lease Obligations United States 5.0% 2018 .2 .5 Foreign 10.7% 2018 to 2036 10.6 9.7 Total Principal Amount 3,837.3 4,298.5 Less: Unamortized Discount and Debt Issuance Costs (18.5 ) (23.4 ) Total Long-term Debt 3,818.8 4,275.1 Less: Current portion of long-term debt (416.4 ) (365.4 ) Long-term Debt $ 3,402.4 $ 3,909.7 Maturities of long-term debt in each of the next five years and beyond are as follows: 2018 $ 416.4 2019 409.0 2020 356.1 2021 433.3 2022 401.0 Thereafter 1,821.5 Total $ 3,837.3 Various debt agreements to which we are a party include financial covenants and other restrictions, including restrictions pertaining to the ability to create property liens and enter into certain sale and leaseback transactions. As of 30 September 2017 , we are in compliance with all the financial and other covenants under our debt agreements. Additional commitments totaling $23.4 are maintained by our foreign subsidiaries, all of which were borrowed and outstanding at 30 September 2017 . 2017 Credit Agreement On 31 March 2017, we entered into a five -year $2,500.0 revolving credit agreement with a syndicate of banks (the “2017 Credit Agreement”), under which senior unsecured debt is available to both the Company and certain of its subsidiaries. The 2017 Credit Agreement provides a source of liquidity for the Company and supports its commercial paper program. The Company’s only financial covenant is a maximum ratio of total debt to total capitalization (total debt plus total equity) no greater than 70% . No borrowings were outstanding under the 2017 Credit Agreement as of 30 September 2017 . The 2017 Credit Agreement terminates and replaces our previous $2,690.0 revolving credit agreement (the “2013 Credit Agreement”), which was to mature 30 April 2018. No borrowings were outstanding under the previous agreement at the time of its termination, and no early termination penalties were incurred. Loss on Extinguishment of Debt In September 2016, we exchanged notes issued to us by Versum in anticipation of the spin-off. The exchange resulted in a loss of $6.9 . Refer to Note 4 , Materials Technologies Separation , for additional information. In September 2015, we made a payment of $146.6 to redeem 3,000,000 Unidades de Fomento (“UF”) Series E 6.30% Bonds due 22 January 2030 that had a carrying value of $130.0 and resulted in a net loss of $16.6 . The fiscal year 2016 and 2015 losses are reflected on the consolidated income statements as “Loss on extinguishment of debt.”

Retirement Benefits

Retirement Benefits	12 Months Ended
	Sep. 30, 2017
Retirement Benefits [Abstract]
Retirement Benefits	16 . RETIREMENT BENEFITS The Company and certain of its subsidiaries sponsor defined benefit pension plans and defined contribution plans that cover a substantial portion of its worldwide employees. The principal defined benefit pension plans are the U.S. salaried pension plan and the U.K. pension plan. These plans were closed to new participants in 2005 and were replaced with defined contribution plans. The principal defined contribution plan is the Retirement Savings Plan, in which a substantial portion of the U.S. employees participate; a similar plan is offered to U.K. employees. We also provide other postretirement benefits consisting primarily of healthcare benefits to U.S. retirees who meet age and service requirements. Defined Benefit Pension Plans Pension benefits earned are generally based on years of service and compensation during active employment. The cost of our defined benefit pension plans included the following components: 2017 2016 2015 U.S. International U.S. International U.S. International Service cost $ 29.0 $ 25.9 $ 36.5 $ 24.3 $ 42.2 $ 31.3 Interest cost 107.5 32.2 110.7 44.3 124.7 57.8 Expected return on plan assets (207.7 ) (75.2 ) (202.0 ) (78.3 ) (202.0 ) (79.8 ) Amortization Net actuarial loss 88.7 54.7 85.3 35.6 78.9 41.4 Prior service cost 2.3 (.1 ) 2.8 (.2 ) 2.8 — Settlements 10.5 1.7 5.1 1.3 18.9 2.3 Curtailments 4.3 (1.3 ) — (1.1 ) 5.3 — Special termination benefits 2.8 .4 2.0 — 7.2 1.5 Other — 1.1 (.3 ) 2.1 1.0 2.1 Net Periodic Benefit Cost – Total $ 37.4 $ 39.4 $ 40.1 $ 28.0 $ 79.0 $ 56.6 Less: Discontinued Operations (.7 ) (4.1 ) (7.9 ) (4.4 ) (12.9 ) (7.7 ) Net Periodic Benefit Cost – Continuing Operations $ 36.7 $ 35.3 $ 32.2 $ 23.6 $ 66.1 $ 48.9 Net periodic benefit cost is primarily included in cost of sales, selling and administrative expense, and pension settlement loss on our consolidated income statements. The amount of net periodic benefit cost capitalized in 2017 , 2016 , and 2015 was not material. Certain of our pension plans provide for a lump sum benefit payment option at the time of retirement, or for corporate officers, six months after their retirement date. A participant’s vested benefit is considered settled upon cash payment of the lump sum. We recognize pension settlement losses when cash payments exceed the sum of the service and interest cost components of net periodic benefit cost of the plan for the fiscal year. In 2017 , 2016 , and 2015 , we recognized pension settlement losses of $10.5 , $5.1 and $19.3 in results from continuing operations, respectively, to accelerate recognition of a portion of actuarial losses deferred in accumulated other comprehensive loss, primarily associated with the U.S. Supplementary Pension Plan. Special termination benefits are primarily related to the business restructuring and cost reduction actions initiated in their respective years. In connection with the disposition of the two divisions comprising the former Materials Technologies segment, we incurred settlement, curtailment, and special termination benefits totaling $6.0 for the year ended 30 September 2017, of which $2.5 was reflected in "Business separation costs" and $3.5 was reflected in the results of discontinued operations on the consolidated income statements. We calculate net periodic benefit cost for a given fiscal year based on assumptions developed at the end of the previous fiscal year. The following table sets forth the weighted average assumptions used in the calculation of net periodic benefit cost: 2017 2016 2015 U.S. International U.S. International U.S. International Discount rate (A) 3.5 % 2.0 % 4.3 % 3.3 % 4.3 % 3.6 % Expected return on plan assets 8.0 % 6.1 % 8.0 % 6.3 % 8.3 % 6.1 % Rate of compensation increase 3.5 % 3.5 % 3.5 % 3.5 % 3.5 % 3.6 % (A) Effective in 2016, the Company began to measure the service cost and interest cost components of pension expense by applying spot rates along the yield curve to the relevant projected cash flows, as we believe this provides a better measurement of these costs. The Company accounted for this in 2016 as a change in accounting estimate and, accordingly, accounted for it on a prospective basis. This change did not affect the measurement of the total benefit obligation. The 2017 discount rates used to measure the service cost and interest cost of our U.S. pension plans were 3.6% and 3.0% , respectively. The rates used to measure the service cost and interest cost of our major International pension plans were 2.1% and 1.8% , respectively. The previous method would have used a single discount rate for both service and interest costs. The projected benefit obligation (PBO) is the actuarial present value of benefits attributable to employee service rendered to date, including the effects of estimated future salary increases. The following table sets forth the weighted average assumptions used in the calculation of the PBO: 2017 2016 U.S. International U.S. International Discount rate 3.8 % 2.4 % 3.5 % 2.0 % Rate of compensation increase 3.5 % 3.6 % 3.5 % 3.5 % The following tables reflect the change in the PBO and the change in the fair value of plan assets based on the plan year measurement date, as well as the amounts recognized in the consolidated balance sheets: 2017 2016 U.S. International U.S. International Change in Projected Benefit Obligation Obligation at beginning of year $ 3,477.7 $ 1,849.6 $ 3,139.9 $ 1,647.9 Service cost 29.0 25.9 36.5 24.3 Interest cost 107.5 32.2 110.7 44.3 Amendments 1.9 — 1.2 — Actuarial (gain) loss (68.0 ) (132.4 ) 380.2 376.4 Divestitures — (34.1 ) — — Curtailments (17.3 ) (4.2 ) (.4 ) (1.2 ) Settlement (gain) loss 7.0 — 5.4 (3.4 ) Special termination benefits 2.8 — 2.0 — Participant contributions — 1.4 — 1.6 Benefits paid (182.9 ) (46.5 ) (197.4 ) (46.6 ) Currency translation/other — 57.6 (.4 ) (193.7 ) Obligation at End of Year $ 3,357.7 $ 1,749.5 $ 3,477.7 $ 1,849.6 2017 2016 U.S. International U.S. International Change in Plan Assets Fair value at beginning of year $ 2,705.3 $ 1,411.1 $ 2,613.6 $ 1,302.8 Actual return on plan assets 319.6 87.9 275.2 273.2 Company contributions 27.2 42.2 13.9 65.4 Participant contributions — 1.4 — 1.6 Divestitures — (3.0 ) — — Benefits paid (182.9 ) (46.5 ) (197.4 ) (46.6 ) Settlements — (5.3 ) — (3.4 ) Currency translation/other — 52.2 — (181.9 ) Fair Value at End of Year $ 2,869.2 $ 1,540.0 $ 2,705.3 $ 1,411.1 Funded Status at End of Year $ (488.5 ) $ (209.5 ) $ (772.4 ) $ (438.5 ) Amounts Recognized Noncurrent assets $ 5.3 $ 13.1 $ — $ — Accrued liabilities (12.6 ) — (24.1 ) — Noncurrent liabilities (481.2 ) (222.6 ) (748.3 ) (438.5 ) Net Amount Recognized $ (488.5 ) $ (209.5 ) $ (772.4 ) $ (438.5 ) The above table in 2016 includes the projected benefit obligation and plan assets associated with discontinued businesses. Upon completion of the spin-off of Versum on 1 October 2016, the Company transferred defined benefit pension assets and obligations that resulted in a net decrease in the underfunded status of the Company's sponsored pension plans of $ 24 . Additionally, as a result of the transfer of unrecognized losses to Versum, accumulated other comprehensive loss, net of tax, decreased by approximately $ 5 . In connection with the sale of PMD to Evonik on 3 January 2017, the Company transferred defined benefit pension obligations that resulted in a net decrease in the underfunded status of the Company's sponsored pension plans of $ 7 . Certain U.S. plans offered terminated vested participants an election to receive their accrued pension benefit as a one-time lump sum payment in 2016. Benefits paid in 2016 include $52.9 of lump sum cash payments in connection with this offering. The changes in plan assets and benefit obligation that have been recognized in other comprehensive income on a pretax basis during 2017 and 2016 consist of the following: 2017 2016 U.S. International U.S. International Net actuarial (gain) loss arising during the period $ (189.8 ) $ (162.0 ) $ 311.8 $ 172.1 Amortization of net actuarial loss (103.3 ) (55.7 ) (90.4 ) (36.5 ) Prior service cost (credit) arising during the period 1.9 — 1.2 (.1 ) Amortization of prior service cost (2.3 ) .1 (2.8 ) .2 Total $ (293.5 ) $ (217.6 ) $ 219.8 $ 135.7 The net actuarial (gain) loss represents the actual changes in the estimated obligation and plan assets that have not yet been recognized in the consolidated income statements and are included in accumulated other comprehensive loss. Actuarial gains arising during 2017 are primarily attributable to higher discount rates and higher than expected return on plan assets. Accumulated actuarial gains and losses that exceed a corridor are amortized over the average remaining service period of participants, which was approximately 9 years as of 30 September 2017 . The components recognized in accumulated other comprehensive loss on a pretax basis at 30 September consisted of: 2017 2016 U.S. International U.S. International Net actuarial loss $ 980.5 $ 551.9 $ 1,273.6 $ 769.6 Prior service cost (credit) 8.1 (1.8 ) 8.5 (1.9 ) Net transition liability — .4 — .4 Total $ 988.6 $ 550.5 $ 1,282.1 $ 768.1 The amount of accumulated other comprehensive loss at 30 September 2017 that is expected to be recognized as a component of net periodic pension cost during fiscal year 2018 , excluding discontinued operations and amounts that may be recognized through settlement losses, is as follows: U.S. International Net actuarial loss $ 88.5 $ 39.9 Prior service cost (credit) 1.5 (.1 ) The accumulated benefit obligation (ABO) is the actuarial present value of benefits attributed to employee service rendered to a particular date, based on current salaries. The ABO for all defined benefit pension plans was $4,842.8 and $4,954.9 as of 30 September 2017 and 2016 , respectively. The following table provides information on pension plans where the benefit liability exceeds the value of plan assets: 30 September 2017 30 September 2016 U.S. International U.S. International Pension Plans with PBO in Excess of Plan Assets: PBO $ 3,116.7 $ 465.7 $ 3,477.7 $ 1,849.6 Fair value of plan assets 2,623.0 243.1 2,705.3 1,411.1 Pension Plans with ABO in Excess of Plan Assets: ABO $ 2,951.0 $ 365.6 $ 3,242.5 $ 1,673.6 Fair value of plan assets 2,623.0 197.1 2,705.3 1,370.1 Included in the tables above are several pension arrangements that are not funded because of jurisdictional practice. The ABO and PBO related to these plans as of 30 September 2017 were $99.0 and $107.8 , respectively. Pension Plan Assets Our pension plan investment strategy is to invest in diversified portfolios to earn a long-term return consistent with acceptable risk in order to pay retirement benefits and meet regulatory funding requirements while minimizing company cash contributions over time. De-risking strategies are also employed for closed plans as funding improves, generally resulting in higher allocations to long duration bonds. The plans invest primarily in passive and actively managed equity and debt securities. Equity investments are diversified geographically and by investment style and market capitalization. Fixed income investments include sovereign, corporate and asset-backed securities generally denominated in the currency of the plan. Asset allocation targets are established based on the long-term return, volatility and correlation characteristics of the asset classes, the profiles of the plans’ liabilities, and acceptable levels of risk. Actual allocations vary from target due to market changes and are reviewed regularly. Assets are routinely rebalanced through contributions, benefit payments, and otherwise as deemed appropriate. The actual and target allocations at the measurement date are as follows: 2017 Target Allocation 2017 Actual Allocation 2016 Actual Allocation U.S. International U.S. International U.S. International Asset Category Equity securities 46-66% 46-57% 58 % 53 % 65 % 60 % Debt securities 32-42% 41-53% 34 % 46 % 28 % 38 % Real estate/other 0-10% 0-2% 7 % 1 % 7 % 1 % Cash — — 1 % — % — % 1 % Total 100 % 100 % 100 % 100 % In 2017, the 8.0% expected return for U.S. plan assets was based on a weighted average of estimated long-term returns of major asset classes and the historical performance of plan assets. The estimated long-term return for equity, debt securities, and real estate is 8.2% , 5.0% , and 7.0% , respectively. In determining asset class returns, we take into account historical long-term returns and the value of active management, as well as other economic and market factors. In 2017, the 6.1% expected rate of return for international plan assets was based on a weighted average return for plans outside the U.S., which vary significantly in size, asset structure and expected returns. The expected asset return for the U.K. plan, which represents over 80% of the assets of our International plans, is 6.6% and was derived from expected equity and debt security returns of 7.3% and 3.5% , respectively. The following table summarizes pension plan assets measured at fair value by asset class (see Note 14 , Fair Value Measurements , for definition of the levels): 30 September 2017 30 September 2016 Total Level 1 Level 2 Level 3 Total Level 1 Level 2 Level 3 U.S. Qualified Pension Plans Cash and cash equivalents $ 13.6 $ 13.6 $ — $ — $ 12.7 $ 12.7 $ — $ — Equity securities 598.6 598.6 — — 637.0 637.0 — — Equity mutual funds 276.5 276.5 — — 300.2 300.2 — — Equity pooled funds 787.0 — 787.0 — 815.5 — 815.5 — Fixed income: Bonds (government and corporate) 985.7 — 985.7 — 747.8 — 747.8 — Real estate pooled funds 207.8 — — 207.8 192.1 — — 192.1 Total U.S. Qualified Pension Plans $ 2,869.2 $ 888.7 $ 1,772.7 $ 207.8 $ 2,705.3 $ 949.9 $ 1,563.3 $ 192.1 International Pension Plans Cash and cash equivalents $ 7.3 $ 7.3 $ — $ — $ 6.6 $ 6.6 $ — $ — Equity pooled funds 821.4 — 821.4 — 854.8 — 854.8 — Fixed income pooled funds 651.3 — 651.3 — 486.9 — 486.9 — Other pooled funds 18.6 — 10.8 7.8 17.0 — 9.7 7.3 Insurance contracts 41.4 — — 41.4 45.8 — — 45.8 Total International Pension Plans $ 1,540.0 $ 7.3 $ 1,483.5 $ 49.2 $ 1,411.1 $ 6.6 $ 1,351.4 $ 53.1 The above table in 2016 includes plan assets associated with discontinued businesses. Upon completion of the spin-off of Versum on 1 October 2016, the Company transferred approximately $ 3 of international plan assets. The following table summarizes changes in fair value of the pension plan assets classified as Level 3, by asset class: Real Estate Pooled Funds Other Pooled Funds Insurance Contracts Total 30 September 2015 $ 174.2 $ 6.6 $ 45.3 $ 226.1 Actual return on plan assets: Assets held at end of year 17.9 .1 3.2 21.2 Assets sold during the period — .3 — .3 Purchases, sales, and settlements, net — .3 (2.7 ) (2.4 ) 30 September 2016 $ 192.1 $ 7.3 $ 45.8 $ 245.2 Actual return on plan assets: Assets held at end of year 15.7 1.2 (1.0 ) 15.9 Assets sold during the period — .3 — .3 Purchases, sales, and settlements, net — (1.0 ) (3.4 ) (4.4 ) 30 September 2017 $ 207.8 $ 7.8 $ 41.4 $ 257.0 The descriptions and fair value methodologies for the U.S. and International pension plan assets are as follows: Cash and Cash Equivalents The carrying amounts of cash and cash equivalents approximate fair value due to the short-term maturity. Equity Securities Equity securities are valued at the closing market price reported on a U.S. or international exchange where the security is actively traded and are therefore classified as Level 1 assets. Mutual and Pooled Funds Shares of mutual funds are valued at the net asset value (NAV) of the fund and are classified as Level 1 assets. Units of pooled funds are valued at the per unit NAV determined by the fund manager and are classified as Level 2 assets. Corporate and Government Bonds Corporate and government bonds are classified as Level 2 assets, as they are either valued at quoted market prices from observable pricing sources at the reporting date or valued based upon comparable securities with similar yields and credit ratings. Real Estate Pooled Funds Real estate pooled funds are classified as Level 3 assets, as they are carried at the estimated fair value of the underlying properties. Estimated fair value is calculated utilizing a combination of key inputs, such as revenue and expense growth rates, terminal capitalization rates, and discount rates. These key inputs are consistent with practices prevailing within the real estate investment management industry. Other Pooled Funds Other pooled funds classified as Level 2 assets are valued at the NAV of the shares held at year end, which is based on the fair value of the underlying investments. Securities and interests classified as Level 3 are carried at the estimated fair value. The estimated fair value is based on the fair value of the underlying investment values, which includes estimated bids from brokers or other third-party vendor sources that utilize expected cash flow streams and other uncorroborated data including counterparty credit quality, default risk, discount rates, and the overall capital market liquidity. Insurance Contracts Insurance contracts are classified as Level 3 assets, as they are carried at contract value, which approximates the estimated fair value. The estimated fair value is based on the fair value of the underlying investment of the insurance company. Contributions and Projected Benefit Payments Pension contributions to funded plans and benefit payments for unfunded plans for fiscal year 2017 were $64.1 . Contributions for funded plans resulted primarily from contractual and regulatory requirements. Benefit payments to unfunded plans were due primarily to the timing of retirements and cost reduction actions. We anticipate contributing $50 to $70 to the defined benefit pension plans in 2018 . These contributions are anticipated to be driven primarily by contractual and regulatory requirements for funded plans and benefit payments for unfunded plans, which are dependent upon timing of retirements. Projected benefit payments, which reflect expected future service, are as follows: U.S. International 2018 $ 158.5 $ 50.9 2019 163.4 53.4 2020 167.3 53.8 2021 171.4 56.8 2022 177.2 59.3 2023-2027 938.5 333.3 These estimated benefit payments are based on assumptions about future events. Actual benefit payments may vary significantly from these estimates. Defined Contribution Plans We maintain a nonleveraged employee stock ownership plan (ESOP) which forms part of the Air Products and Chemicals, Inc. Retirement Savings Plan (RSP). The ESOP was established in May of 2002. The balance of the RSP is a qualified defined contribution plan including a 401(k) elective deferral component. A substantial portion of U.S. employees are eligible and participate. We treat dividends paid on ESOP shares as ordinary dividends. Under existing tax law, we may deduct dividends which are paid with respect to shares held by the plan. Shares of the Company’s common stock in the ESOP totaled 2,483,225 as of 30 September 2017 . Our contributions to the RSP include a Company core contribution for certain eligible employees who do not receive their primary retirement benefit from the defined benefit pension plans, with the core contribution based on a percentage of pay that is dependent on years of service. For the RSP, we also make matching contributions on overall employee contributions as a percentage of the employee contribution and include an enhanced contribution for certain eligible employees that do not participate in the defined benefit pension plans. Worldwide contributions, excluding discontinued operations, expensed to income in 2017 , 2016 , and 2015 were $33.7 , $34.6 , and $36.8 , respectively. Other Postretirement Benefits We provide other postretirement benefits consisting primarily of healthcare benefits to certain U.S. retirees who meet age and service requirements. The healthcare benefit is a continued medical benefit until the retiree reaches age 65. Healthcare benefits are contributory, with contributions adjusted periodically. The retiree medical costs are capped at a specified dollar amount, with the retiree contributing the remainder. The cost of our other postretirement benefit plans includes the following components: 2017 2016 2015 Service cost $ 1.1 $ 2.2 $ 2.8 Interest cost 1.6 2.0 2.2 Amortization of net actuarial loss .2 .7 .8 Net Periodic Postretirement Cost $ 2.9 $ 4.9 $ 5.8 Less: Discontinued Operations $ — $ (.4 ) $ (.7 ) Net Periodic Postretirement Cost – Continuing Operations $ 2.9 $ 4.5 $ 5.1 We calculate net periodic postretirement cost for a given fiscal year based on assumptions developed at the end of the previous fiscal year. The discount rate assumption used in the calculation of net periodic postretirement cost for 2017 , 2016 , and 2015 was 1.9% , 2.4% , and 2.6% , respectively. We measure the other postretirement benefits as of 30 September. The discount rate assumption used in the calculation of the accumulated postretirement benefit obligation was 2.4% and 1.9% for 2017 and 2016 , respectively. The following table reflects the change in the accumulated postretirement benefit obligation and the amounts recognized in the consolidated balance sheets: 2017 2016 Obligation at beginning of year $ 86.3 $ 86.9 Service cost 1.1 2.2 Interest cost 1.6 2.0 Actuarial loss (gain) (7.2 ) 7.5 Curtailment gain (3.5 ) — Benefits paid (11.3 ) (12.3 ) Obligation at End of Year $ 67.0 $ 86.3 Amounts Recognized Accrued liabilities $ 10.0 $ 11.4 Noncurrent liabilities 57.0 74.9 In 2016, the above table included the projected benefit obligations associated with discontinued businesses. The changes in benefit obligation that have been recognized in other comprehensive income on a pretax basis during 2017 and 2016 for our other postretirement benefit plans consist of the following: 2017 2016 Net actuarial loss (gain) arising during the period $ (10.7 ) $ 7.5 Amortization of net actuarial loss (.2 ) (.7 ) Total $ (10.9 ) $ 6.8 The net actuarial loss recognized in accumulated other comprehensive loss on a pretax basis was $7.8 at 30 September 2017 and $18.7 at 30 September 2016 . Of the 30 September 2017 net actuarial loss, it is estimated that $.3 , which excludes discontinued operations, will be amortized into net periodic postretirement cost during fiscal year 2018 . The effect of a change in the healthcare trend rate is tempered by a cap on the average retiree medical cost. The expected per capita claims costs are currently assumed to be greater than the annual cap; therefore, the assumed healthcare cost trend rate, ultimate trend rate, and the year the ultimate trend rate is reached in 2017 and 2016 does not apply as it has no impact on plan obligations. Projected benefit payments are as follows: 2018 $ 10.1 2019 9.5 2020 9.0 2021 8.4 2022 7.7 2023-2027 24.2 These estimated benefit payments are based on assumptions about future events. Actual benefit payments may vary significantly from these estimates.

Commitments and Contingencies

Commitments and Contingencies	12 Months Ended
	Sep. 30, 2017
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	17 . COMMITMENTS AND CONTINGENCIES LITIGATION We are involved in various legal proceedings, including commercial, competition, environmental, health, safety, product liability, and insurance matters. In September 2010, the Brazilian Administrative Council for Economic Defense (CADE) issued a decision against our Brazilian subsidiary, Air Products Brasil Ltda., and several other Brazilian industrial gas companies for alleged anticompetitive activities. CADE imposed a civil fine of R$179.2 million (approximately $57 at 30 September 2017 ) on Air Products Brasil Ltda. This fine was based on a recommendation by a unit of the Brazilian Ministry of Justice, whose investigation began in 2003, alleging violation of competition laws with respect to the sale of industrial and medical gases. The fines are based on a percentage of our total revenue in Brazil in 2003. We have denied the allegations made by the authorities and filed an appeal in October 2010 with the Brazilian courts. On 6 May 2014, our appeal was granted and the fine against Air Products Brasil Ltda. was dismissed. CADE has appealed that ruling and the matter remains pending. We, with advice of our outside legal counsel, have assessed the status of this matter and have concluded that, although an adverse final judgment after exhausting all appeals is possible, such a judgment is not probable. As a result, no provision has been made in the consolidated financial statements. We estimate the maximum possible loss to be the full amount of the fine of R$179.2 million (approximately $57 at 30 September 2017 ) plus interest accrued thereon until final disposition of the proceedings. Other than this matter, we do not currently believe there are any legal proceedings, individually or in the aggregate, that are reasonably possible to have a material impact on our financial condition, results of operations, or cash flows. ENVIRONMENTAL In the normal course of business, we are involved in legal proceedings under the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA: the federal Superfund law); Resource Conservation and Recovery Act (RCRA); and similar state and foreign environmental laws relating to the designation of certain sites for investigation or remediation. Presently, there are approximately 32 sites on which a final settlement has not been reached where we, along with others, have been designated a potentially responsible party by the Environmental Protection Agency or are otherwise engaged in investigation or remediation, including cleanup activity at certain of our current and former manufacturing sites. We continually monitor these sites for which we have environmental exposure. Accruals for environmental loss contingencies are recorded when it is probable that a liability has been incurred and the amount of loss can be reasonably estimated. The consolidated balance sheets at 30 September 2017 and 2016 included an accrual of $83.6 and $81.4 , respectively, primarily as part of other noncurrent liabilities. The environmental liabilities will be paid over a period of up to 30 years . We estimate the exposure for environmental loss contingencies to range from $83 to a reasonably possible upper exposure of $97 as of 30 September 2017 . Actual costs to be incurred at identified sites in future periods may vary from the estimates, given inherent uncertainties in evaluating environmental exposures. Using reasonably possible alternative assumptions of the exposure level could result in an increase to the environmental accrual. Due to the inherent uncertainties related to environmental exposures, a significant increase to the reasonably possible upper exposure level could occur if a new site is designated, the scope of remediation is increased, a different remediation alternative is identified, or a significant increase in our proportionate share occurs. We do not expect that any sum we may have to pay in connection with environmental matters in excess of the amounts recorded or disclosed above would have a material adverse impact on our financial position or results of operations in any one year. Pace At 30 September 2017 , $28.9 of the environmental accrual was related to the Pace facility. In 2006, we sold our Amines business, which included operations at Pace, Florida, and recognized a liability for retained environmental obligations associated with remediation activities at Pace. We are required by the Florida Department of Environmental Protection (FDEP) and the United States Environmental Protection Agency (USEPA) to continue our remediation efforts. We estimated that it would take a substantial period of time to complete the groundwater remediation, and the costs through completion were estimated to range from $42 to $52 . As no amount within the range was a better estimate than another, we recognized a pretax expense in fiscal 2006 of $42 as a component of income from discontinued operations and recorded an environmental accrual of $42 in continuing operations on the consolidated balance sheets. There has been no change to the estimated exposure range related to the Pace facility. We have implemented many of the remedial corrective measures at the Pace facility required under 1995 Consent Orders issued by the FDEP and the USEPA. Contaminated soils have been bioremediated, and the treated soils have been secured in a lined on-site disposal cell. Several groundwater recovery systems have been installed to contain and remove contamination from groundwater. We completed an extensive assessment of the site to determine how well existing measures are working, what additional corrective measures may be needed, and whether newer remediation technologies that were not available in the 1990s might be suitable to more quickly and effectively remove groundwater contaminants. Based on assessment results, we completed a focused feasibility study that has identified alternative approaches that may more effectively remove contaminants. We continue to review alternative remedial approaches with the FDEP and recently started additional field work to support the design of an improved groundwater recovery network with the objective of targeting areas of higher contaminant concentration and avoiding areas of high groundwater iron which has proven to be a significant operability issue for the project. In the first quarter of 2015, we entered into a new Consent Order with the FDEP requiring us to continue our remediation efforts at the Pace facility. The costs we are incurring under the new Consent Order are expected to be consistent with our previous estimates. Piedmont At 30 September 2017 , $16.7 of the environmental accrual was related to the Piedmont site. On 30 June 2008, we sold our Elkton, Maryland, and Piedmont, South Carolina, production facilities and the related North American atmospheric emulsions and global pressure sensitive adhesives businesses. In connection with the sale, we recognized a liability for retained environmental obligations associated with remediation activities at the Piedmont site. This site is under active remediation for contamination caused by an insolvent prior owner. We are required by the South Carolina Department of Health and Environmental Control (SCDHEC) to address both contaminated soil and groundwater. Numerous areas of soil contamination have been addressed, and contaminated groundwater is being recovered and treated. On 13 June 2017, the SCDHEC issued its final approval to the site-wide feasibility study, and with that we will be moving towards a record of decision for the Piedmont site and into the final remedial design phase of this project. We estimate that it will take until 2019 to complete source area remediation, with groundwater recovery and treatment continuing through 2029 . Thereafter, we are expecting this site to go into a state of monitored natural attenuation through 2047. We recognized a pretax expense in 2008 of $24 as a component of income from discontinued operations and recorded an environmental liability of $24 in continuing operations on the consolidated balance sheets. There have been no significant changes to the estimated exposure. Pasadena At 30 September 2017 , $12.1 of the environmental accrual was related to the Pasadena site. During the fourth quarter of 2012, management committed to permanently shutting down our polyurethane intermediates (PUI) production facility in Pasadena, Texas. In shutting down and dismantling the facility, we have undertaken certain obligations related to soil and groundwater contaminants. We have been pumping and treating groundwater to control off-site contaminant migration in compliance with regulatory requirements and under the approval of the Texas Commission on Environmental Quality (TCEQ). We estimate that the pump and treat system will continue to operate until 2042 . We plan to perform additional work to address other environmental obligations at the site. This additional work includes remediating, as required, impacted soils, investigating groundwater west of the former PUI facility, performing post closure care for two closed RCRA surface impoundment units, and establishing engineering controls. In 2012, we estimated the total exposure at this site to be $13 . There have been no significant changes to the estimated exposure. ASSET RETIREMENT OBLIGATIONS Our asset retirement obligations are primarily associated with on-site long-term supply contracts under which we have built a facility on land owned by the customer and are obligated to remove the facility at the end of the contract term. The retirement of assets includes the contractually required removal of a long-lived asset from service and encompasses the sale, removal, abandonment, recycling, or disposal of the assets as required at the end of the contract terms. The timing and/or method of settlement of these obligations are conditional on a future event that may or may not be within our control. Changes to the carrying amount of our asset retirement obligations are as follows: Balance at 30 September 2015 $ 109.4 Additional accruals 10.4 Liabilities settled (4.4 ) Accretion expense 5.4 Currency translation adjustment (.9 ) Balance at 30 September 2016 $ 119.9 Additional accruals 22.7 Liabilities settled (4.1 ) Accretion expense 5.8 Currency translation adjustment .4 Balance at 30 September 2017 $ 144.7 These obligations are primarily reflected in "Other noncurrent liabilities" on the consolidated balance sheets. GUARANTEES AND WARRANTIES In April 2015, we entered into joint venture arrangements in Saudi Arabia. An equity bridge loan has been provided to the joint venture until 2020 to fund equity commitments. We guaranteed the repayment of our 25% share of this loan, and our venture partner guaranteed repayment of its share. Our maximum exposure under the guarantee is approximately $100 . As of 30 September 2017 and 2016 , we recorded a noncurrent liability of $94.4 for our obligation to make future equity contributions based on our proportionate share of the advances received by the joint venture under the loan. Air Products has also entered into a long-term sale of equipment contract with the joint venture to engineer, procure, and construct the industrial gas facilities that will supply gases to Saudi Aramco. We have provided bank guarantees to the joint venture of up to $262 to support our performance under the contract. Exposures under the guarantees decline over time and will be completely extinguished after completion of the project. We are party to an equity support agreement and operations guarantee related to an air separation facility constructed in Trinidad for a venture in which we own 50% . At 30 September 2017 , maximum potential payments under joint and several guarantees were $28.0 . Exposures under the guarantees decline over time and will be completely extinguished by 2024 . During the first quarter of 2014, we sold the remaining portion of our Homecare business and entered into an operations guarantee related to obligations under certain homecare contracts assigned in connection with the transaction. Our maximum potential payment under the guarantee is £20 million (approximately $25 at 30 September 2017 ), and our exposure will be extinguished by 2020 . To date, no equity contributions or payments have been made since the inception of these guarantees. The fair value of the above guarantees is not material. We, in the normal course of business operations, have issued product warranties related to equipment sales. Also, contracts often contain standard terms and conditions which typically include a warranty and indemnification to the buyer that the goods and services purchased do not infringe on third-party intellectual property rights. The provision for estimated future costs relating to warranties is not material to the consolidated financial statements. We do not expect that any sum we may have to pay in connection with guarantees and warranties will have a material adverse effect on our consolidated financial condition, liquidity, or results of operations. UNCONDITIONAL PURCHASE OBLIGATIONS We are obligated to make future payments under unconditional purchase obligations as summarized below: 2018 $ 822 2019 234 2020 275 2021 309 2022 285 Thereafter 4,608 Total $ 6,533 Approximately $5,600 of our unconditional purchase obligations relate to helium purchases, which include crude feedstock supply to multiple helium refining plants in North America as well as refined helium purchases from sources around the world. As a rare byproduct of natural gas production in the energy sector, these helium sourcing agreements are medium- to long-term and contain take-or-pay provisions. The refined helium is distributed globally and sold as a merchant gas, primarily under medium-term requirements contracts. While contract terms in the energy sector are longer than those in merchant, helium is a rare gas used in applications with few or no substitutions because of its unique physical and chemical properties. Approximately $280 of our long-term unconditional purchase obligations relate to feedstock supply for numerous HyCO (hydrogen, carbon monoxide, and syngas) facilities. The price of feedstock supply is principally related to the price of natural gas. However, long-term take-or-pay sales contracts to HyCO customers are generally matched to the term of the feedstock supply obligations and provide recovery of price increases in the feedstock supply. Due to the matching of most long-term feedstock supply obligations to customer sales contracts, we do not believe these purchase obligations would have a material effect on our financial condition or results of operations. The unconditional purchase obligations also include other product supply and purchase commitments and electric power and natural gas supply purchase obligations, which are primarily pass-through contracts with our customers. Purchase commitments to spend approximately $300 for additional plant and equipment are included in the unconditional purchase obligations in 2018 . In addition, we have purchase commitments totaling approximately $180 in 2018 relating to our long-term sale of equipment project for Saudi Aramco’s Jazan oil refinery.

Capital Stock

Capital Stock	12 Months Ended
	Sep. 30, 2017
Equity [Abstract]
Capital Stock	18 . CAPITAL STOCK Common Stock Authorized common stock consists of 300 million shares with a par value of $1 per share. As of 30 September 2017 , 249 million shares were issued, with 218 million outstanding. On 15 September 2011, the Board of Directors authorized the repurchase of up to $1,000 of our outstanding common stock. We repurchase shares pursuant to Rules 10b5-1 and 10b-18 under the Securities Exchange Act of 1934, as amended, through repurchase agreements established with several brokers. We did not purchase any of our outstanding shares during fiscal year 2017. At 30 September 2017 , $485.3 in share repurchase authorization remains. The following table reflects the changes in common shares: Year ended 30 September 2017 2016 2015 Number of Common Shares Outstanding Balance, beginning of year 217,350,825 215,359,113 213,538,144 Issuance of treasury shares for stock option and award plans 995,249 1,991,712 1,820,969 Balance, end of year 218,346,074 217,350,825 215,359,113 Preferred Stock Authorized preferred stock consists of 25 million shares with a par value of $1 per share, of which 2.5 million were designated as Series A Junior Participating Preferred Stock. There were no shares issued or outstanding as of 30 September 2017 and 2016 .

Share-Based Compensation

Share-Based Compensation	12 Months Ended
	Sep. 30, 2017
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Share-Based Compensation	19 . SHARE-BASED COMPENSATION We have various share-based compensation programs, which include deferred stock units, stock options, and restricted stock. Under all programs, the terms of the awards are fixed at the grant date. We issue shares from treasury stock upon the payout of deferred stock units, the exercise of stock options, and the issuance of restricted stock awards. Share information presented is on a total company basis. As of 30 September 2017 , there were 4,922,382 shares available for future grant under our Long-Term Incentive Plan (LTIP), which is shareholder approved. In connection with the spin-off of Versum, the Company adjusted the number of deferred stock units and stock options pursuant to existing anti-dilution provisions in the LTIP to preserve the intrinsic value of the awards immediately before and after the separation. The outstanding awards will continue to vest over the original vesting period defined at the grant date. Outstanding awards at the time of spin-off were primarily converted into awards of the holders' employer following the separation. Stock awards held upon separation were adjusted based upon the conversion ratio of Air Products' New York Stock Exchange (“NYSE”) volume weighted-average closing stock price on 30 September 2016 ( $150.35 ) to the NYSE volume weighted-average opening stock price on 3 October 2016 ( $140.38 ), or 1.071 . The adjustment to the awards did not result in incremental fair value, and no incremental compensation expense was recorded related to the conversion of these awards. Share-based compensation cost recognized in the consolidated income statements is summarized below: 2017 2016 2015 Before-Tax Share-Based Compensation Cost – Total $ 40.7 $ 37.6 $ 45.7 Before-Tax Share-Based Compensation Cost – Discontinued Operations .8 6.6 6.2 Before-Tax Share-Based Compensation Cost – Continuing Operations $ 39.9 $ 31.0 $ 39.5 Income tax benefit – Continuing Operations (14.0 ) (10.8 ) (13.8 ) After-Tax Share-Based Compensation Cost – Continuing Operations $ 25.9 $ 20.2 $ 25.7 Before-tax share-based compensation cost is primarily included in selling and administrative expense on our consolidated income statements. The amount of share-based compensation cost capitalized in 2017 , 2016 , and 2015 was not material. On a total company basis, before-tax share-based compensation cost by type of program was as follows: 2017 2016 2015 Deferred stock units $ 34.5 $ 29.9 $ 28.8 Stock options 1.4 4.2 12.6 Restricted stock 4.8 3.5 4.3 Before-Tax Share-Based Compensation Cost – Total $ 40.7 $ 37.6 $ 45.7 Deferred Stock Units We have granted deferred stock units to executives, selected employees, and outside directors. These deferred stock units entitle the recipient to one share of common stock upon vesting, which is conditioned, for employee recipients, on continued employment during the deferral period and may be conditioned on achieving certain performance targets. We grant deferred stock unit awards with a two - to five -year deferral period that is subject to payout upon death, disability, or retirement. Deferred stock units issued to outside directors are paid after service on the Board of Directors ends at the time elected by the director (not to exceed 10 years after service ends). We generally expense the grant-date fair value of these awards on a straight-line basis over the vesting period; however, expense recognition is accelerated for retirement eligible individuals who meet the requirements for vesting upon retirement. Market-based deferred stock units vest as long as the employee continues to be employed by the Company and upon the achievement of the performance target. The performance target, which is approved by the Compensation Committee, is the Company’s total shareholder return (share price appreciation and dividends paid) in relation to a defined peer group over a three ‑year performance period. In 2017 , we granted 117,692 market-based deferred stock units that are earned out at the end of the three -year performance period beginning 1 October 2016 and ending 30 September 2019. In 2016 , we granted 130,167 market-based deferred stock units that are earned out at the end of the three -year performance period beginning 1 October 2015 and ending 30 September 2018. The fair value of market-based deferred stock units was estimated using a Monte Carlo simulation model as these equity awards are tied to a market condition. The model utilizes multiple input variables that determine the probability of satisfying the market condition stipulated in the grant and calculates the fair value of the awards. We generally expense the grant-date fair value of these awards on a straight-line basis over the vesting period. The calculation of the fair value of market-based deferred stock units used the following assumptions: 2017 2016 Expected volatility 20.6 % 20.5 % Risk-free interest rate 1.4 % 1.2 % Expected dividend yield 2.5 % 2.2 % The estimated grant-date fair value of market-based deferred stock units was $156.87 and $135.49 per unit in 2017 and 2016 , respectively. In addition, during 2017 , we granted 165,121 time-based deferred stock units at a weighted average grant-date fair value of $143.75 . Deferred Stock Units Shares (000) Weighted Average Grant-Date Fair Value Outstanding at 30 September 2016 1,001 $ 119.44 Equitable adjustment upon separation (A) 65 — Surrender upon separation (B) (89 ) 132.88 Granted 283 148.89 Paid out (235 ) 83.65 Forfeited/adjustments (50 ) 121.99 Outstanding at 30 September 2017 975 $ 127.29 (A) Applicable deferred stock units have been adjusted by the conversion ratio of 1.071 to preserve the intrinsic value immediately before and after the spin-off of Versum. (B) In connection with the spin-off of Versum, EMD employees surrendered their outstanding Air Products equity awards, which were converted into Versum equity awards of equivalent fair value. Cash payments made for deferred stock units were $2.1 , $2.9 , and $9.6 in 2017 , 2016 , and 2015 , respectively. As of 30 September 2017 , there was $39.0 of unrecognized compensation cost related to deferred stock units. The cost is expected to be recognized over a weighted average period of 2.0 years . The total fair value of deferred stock units paid out during 2017 , 2016 , and 2015 , including shares vested in prior periods, was $36.6 , $41.6 , and $35.5 , respectively. Stock Options We have granted awards of options to purchase common stock to executives and selected employees. The exercise price of stock options equals the market price of our stock on the date of the grant. Options generally vest incrementally over three years , and remain exercisable for ten years from the date of grant. In 2017 and 2016, no stock options were awarded. Fair values of stock options were estimated using a Black Scholes model that used the assumptions noted in the table below. Expected volatility and expected dividend yield are based on actual historical experience of our stock and dividends over the historical period equal to the expected life. The expected life represents the period of time that options granted are expected to be outstanding based on an analysis of Company-specific historical exercise data. Ranges are used when certain groups of employees exhibit different behavior, such as timing of exercise. The risk-free rate is based on the U.S. Treasury Strips with terms equal to the expected time of exercise as of the grant date. 2015 Expected volatility 30.3 % Expected dividend yield 2.6 % Expected life (in years) 7.5 Risk-free interest rate 2.2 % The weighted average grant-date fair value of options granted during 2015 was $37.19 per option. A summary of stock option activity is presented below: Stock Options Shares (000) Weighted Average Exercise Price Outstanding at 30 September 2016 3,916 $ 90.28 Equitable adjustment upon separation (A) 277 — Surrender upon separation (B) (102 ) 97.63 Exercised (886 ) 80.76 Forfeited (3 ) 105.28 Outstanding at 30 September 2017 3,202 $ 84.85 Exercisable at 30 September 2017 3,149 $ 84.00 Stock Options Weighted Average Remaining Contractual Term (in years) Aggregate Intrinsic Value Outstanding at 30 September 2017 4.3 $ 213 Exercisable at 30 September 2017 4.3 $ 212 (A) Applicable deferred stock units have been adjusted by the conversion ratio of 1.071 to preserve the intrinsic value immediately before and after the spin-off of Versum. (B) In connection with the spin-off of Versum, EMD employees surrendered their outstanding Air Products equity awards, which were converted into Versum equity awards of equivalent fair value. The aggregate intrinsic value represents the amount by which our closing stock price of $151.22 as of 30 September 2017 exceeds the exercise price multiplied by the number of in-the-money options outstanding or exercisable. On a total company basis, the intrinsic value of stock options exercised during 2017 , 2016 , and 2015 was $57.3 , $115.3 , and $115.5 , respectively. Compensation cost is generally recognized over the stated vesting period consistent with the terms of the arrangement (i.e., either on a straight-line or graded-vesting basis). Expense recognition is accelerated for retirement-eligible individuals who would meet the requirements for vesting of awards upon their retirement. As of 30 September 2017 , there was $.1 of unrecognized compensation cost related to nonvested stock options, which is expected to be recognized over a weighted average period of 0.2 years . Cash received from option exercises during 2017 was $68.4 . The total tax benefit realized from stock option exercises in 2017 was $19.9 , of which $13.9 was the excess tax benefit. Restricted Stock The grant-date fair value of restricted stock is estimated on the date of grant based on the closing price of the stock, and compensation cost is generally amortized to expense on a straight-line basis over the vesting period during which employees perform related services. Expense recognition is accelerated for retirement-eligible individuals who would meet the requirements for vesting of awards upon their retirement. We have issued shares of restricted stock to certain officers. Participants are entitled to cash dividends and to vote their respective shares. Restrictions on shares lift in one to four years or upon the earlier of retirement, death, or disability. The shares are nontransferable while subject to forfeiture. A summary of restricted stock activity is presented below: Restricted Stock Shares (000) Weighted Average Grant-Date Fair Value Outstanding at 30 September 2016 85 $ 128.16 Vested (29 ) 113.50 Outstanding at 30 September 2017 56 $ 135.74 As of 30 September 2017 , there was $.4 of unrecognized compensation cost related to restricted stock awards. The cost is expected to be recognized over a weighted average period of 1.4 years . The total fair value of restricted stock vested during 2017 , 2016 , and 2015 was $4.1 , $4.3 , and $1.4 , respectively.

Accumulated Other Comprehensive

Accumulated Other Comprehensive Loss	12 Months Ended
	Sep. 30, 2017
Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract]
Accumulated Other Comprehensive Loss	20 . ACCUMULATED OTHER COMPREHENSIVE LOSS The table below summarizes changes in AOCL, net of tax, attributable to Air Products: Derivatives qualifying as hedges Foreign currency translation adjustments Pension and postretirement benefits Total Balance at 30 September 2014 $ (28.5 ) $ (268.7 ) $ (944.7 ) $ (1,241.9 ) Other comprehensive loss before reclassifications (35.0 ) (699.3 ) (278.5 ) (1,012.8 ) Amounts reclassified from AOCL 20.8 — 97.0 117.8 Net current period other comprehensive loss $ (14.2 ) $ (699.3 ) $ (181.5 ) $ (895.0 ) Amount attributable to noncontrolling interest .2 (11.5 ) .3 (11.0 ) Balance at 30 September 2015 $ (42.9 ) $ (956.5 ) $ (1,126.5 ) $ (2,125.9 ) Other comprehensive income (loss) before reclassifications 13.7 9.9 (335.1 ) (311.5 ) Amounts reclassified from AOCL (36.0 ) 2.7 87.2 53.9 Net current period other comprehensive income (loss) $ (22.3 ) $ 12.6 $ (247.9 ) $ (257.6 ) Amount attributable to noncontrolling interest (.2 ) 5.4 (.4 ) 4.8 Balance at 30 September 2016 $ (65.0 ) $ (949.3 ) $ (1,374.0 ) $ (2,388.3 ) Other comprehensive income (loss) before reclassifications (12.6 ) 101.9 251.6 340.9 Amounts reclassified from AOCL 24.2 57.3 110.7 192.2 Net current period other comprehensive income $ 11.6 $ 159.2 $ 362.3 $ 533.1 Spin-off of Versum .2 6.0 5.3 11.5 Amount attributable to noncontrolling interest (.1 ) 3.0 .8 3.7 Balance at 30 September 2017 $ (53.1 ) $ (787.1 ) $ (1,007.2 ) $ (1,847.4 ) The table below summarizes the reclassifications out of accumulated other comprehensive loss and the affected line item on the consolidated income statements: 2017 2016 2015 (Gain) Loss on Cash Flow Hedges, net of tax Sales/Cost of sales $ 18.3 $ .2 $ .6 Other income (expense), net 5.1 (46.2 ) 16.9 Interest expense .8 10.0 3.3 Total (Gain) Loss on Cash Flow Hedges, net of tax $ 24.2 $ (36.0 ) $ 20.8 Currency Translation Adjustment Business restructuring and cost reduction actions (A) $ 8.2 $ — $ — Income from discontinued operations, net of tax (B) 49.1 2.7 — Total Currency Translation Adjustment $ 57.3 $ 2.7 $ — Pension and Postretirement Benefits, net of tax (C) $ 110.7 $ 87.2 $ 97.0 (A) The fiscal year 2017 impact relates to the planned sale of a non-industrial gas hardgoods business in the Industrial Gases – Americas segment recorded in the third quarter. (B) The fiscal year 2017 impact relates to the sale of PMD during the second quarter. The fiscal year 2016 impact primarily relates to the sale of an equity affiliate in the first quarter. (C) The components include items such as prior service cost amortization, actuarial loss amortization, and settlements and are reflected in net periodic benefit cost. Refer to Note 16 , Retirement Benefits .

Earnings per Share

Earnings per Share	12 Months Ended
	Sep. 30, 2017
Earnings Per Share [Abstract]
Earnings per Share	21 . EARNINGS PER SHARE The following table sets forth the computation of basic and diluted earnings per share (EPS): 30 September 2017 2016 2015 Numerator Income from continuing operations $ 1,134.4 $ 1,099.5 $ 933.3 Income (Loss) from discontinued operations 1,866.0 (468.4 ) 344.6 Net Income Attributable to Air Products $ 3,000.4 $ 631.1 $ 1,277.9 Denominator (in millions) Weighted average common shares — Basic 218.0 216.4 214.9 Effect of dilutive securities Employee stock option and other award plans 1.8 1.9 2.4 Weighted average common shares — Diluted 219.8 218.3 217.3 Basic EPS Attributable to Air Products Income from continuing operations $ 5.20 $ 5.08 $ 4.34 Income (Loss) from discontinued operations 8.56 (2.16 ) 1.61 Net Income Attributable to Air Products $ 13.76 $ 2.92 $ 5.95 Diluted EPS Attributable to Air Products Income from continuing operations $ 5.16 $ 5.04 $ 4.29 Income (Loss) from discontinued operations 8.49 (2.15 ) 1.59 Net Income Attributable to Air Products $ 13.65 $ 2.89 $ 5.88 Diluted EPS attributable to Air Products reflects the potential dilution that could occur if stock options or other share-based awards were exercised or converted into common stock. The dilutive effect is computed using the treasury stock method, which assumes all share-based awards are exercised and the hypothetical proceeds from exercise are used by the Company to purchase common stock at the average market price during the period. The incremental shares (difference between shares assumed to be issued versus purchased), to the extent they would have been dilutive, are included in the denominator of the diluted EPS calculation. There were no antidilutive outstanding share-based awards in fiscal year 2017. Outstanding share-based awards of .2 million shares were antidilutive and therefore excluded from the computation of diluted EPS for 2016 and 2015 .

Income Taxes

Income Taxes	12 Months Ended
	Sep. 30, 2017
Income Tax Disclosure [Abstract]
Income Taxes	22 . INCOME TAXES The following table summarizes the income of U.S. and foreign operations before taxes: 2017 2016 2015 Income from Continuing Operations before Taxes United States $ 669.8 $ 631.7 $ 507.5 Foreign 666.2 775.9 606.3 Income from equity affiliates 80.1 147.0 152.3 Total $ 1,416.1 $ 1,554.6 $ 1,266.1 The following table shows the components of the provision for income taxes: 2017 2016 2015 Current Tax Provision Federal $ 62.8 $ 171.0 $ 117.0 State 7.0 21.2 8.1 Foreign 229.1 178.6 165.7 298.9 370.8 290.8 Deferred Tax Provision Federal 1.4 45.0 1.5 State 6.0 2.8 17.8 Foreign (45.4 ) 14.0 (9.9 ) (38.0 ) 61.8 9.4 Income Tax Provision $ 260.9 $ 432.6 $ 300.2 The effective tax rate equals the income tax provision divided by income from continuing operations before taxes. A reconciliation of the differences between the United States federal statutory tax rate and the effective tax rate is as follows: (Percent of income before taxes) 2017 2016 2015 U.S. federal statutory tax rate 35.0 % 35.0 % 35.0 % State taxes, net of federal benefit 1.0 1.2 1.1 Income from equity affiliates (2.0 ) (3.3 ) (4.0 ) Foreign tax differentials (7.9 ) (6.6 ) (5.9 ) U.S. taxes on foreign earnings (2.2 ) (3.1 ) (2.1 ) Domestic production activities (.8 ) (.8 ) (1.0 ) Non-deductible goodwill impairment charge 3.6 — — Non-U.S. subsidiary tax election (7.7 ) — — Business separation costs .2 4.2 .2 Share-based compensation (1.2 ) — — Other .4 1.2 .4 Effective Tax Rate 18.4 % 27.8 % 23.7 % Total company income tax payments, net of refunds, were $1,348.8 in 2017 , $440.8 in 2016 , and $392.9 in 2015 . Foreign tax differentials represent the differences between foreign earnings subject to foreign tax rates lower than the U.S. federal statutory tax rate of 35.0% . Foreign earnings are subject to local country tax rates that are generally below the 35.0% U.S. federal statutory rate and include tax holidays and incentives. As a result, our effective non-U.S. tax rate is typically lower than the U.S. statutory rate. If foreign pre-tax earnings increase relative to U.S. pre-tax earnings, this rate difference could increase. The jurisdictions in which we earn pre-tax earnings subject to lower foreign taxes than the U.S. statutory rate include South Korea, Taiwan, the United Kingdom, China, Canada, Spain and Belgium. As approximately 80% of the undistributed earnings are in countries with a statutory tax rate of 24% or higher, we do not generate a disproportionate amount of taxable income in countries with very low tax rates. U.S. taxes on foreign earnings are a tax benefit primarily due to foreign tax credits on the repatriation of foreign earnings to the U.S. In 2017 , the effective tax rate was impacted by a tax election made with respect to a Chilean holding company resulting in an income tax benefit of $111.4 on tax losses related to investments in Chile. The effective tax rate was also impacted by a goodwill impairment charge of $145.3 for which no tax benefits were available. See Note 10 , Goodwill , for additional information regarding the impairment charge. During the first quarter of fiscal year 2017, we adopted new accounting guidance that requires excess tax benefits and deficiencies from share-based compensation to be recognized in the income statement rather than in additional paid-in capital on the balance sheet. As a result of applying this change prospectively, we recognized $17.6 of excess tax benefits in our provision for income taxes during fiscal year 2017. See Note 2 , New Accounting Guidance , for additional information. In 2016 , the effective tax rate was impacted by tax costs of $51.8 incurred in anticipation of the tax-free spin-off of Versum, primarily for a dividend declared during the third quarter of 2016 to repatriate $443.8 from a subsidiary in South Korea to the U.S. Previously, most of these foreign earnings were considered to be indefinitely reinvested. In addition, a tax benefit was not available on a significant portion of the business separation costs. See Note 4 , Materials Technologies Separation , for additional information. The significant components of deferred tax assets and liabilities are as follows: 30 September 2017 2016 Gross Deferred Tax Assets Retirement benefits and compensation accruals $ 370.1 $ 527.6 Tax loss carryforwards 64.5 101.1 Tax credits and other tax carryforwards 76.1 56.0 Reserves and accruals 88.2 74.9 Partnership and other investments — 5.8 Currency losses 20.7 — Other 37.2 19.3 Valuation allowance (107.7 ) (165.1 ) Deferred Tax Assets 549.1 619.6 Gross Deferred Tax Liabilities Plant and equipment 1,035.6 985.1 Currency gains — 46.8 Unremitted earnings of foreign entities 20.9 5.4 Partnership and other investments 5.4 — Intangible assets 81.9 91.0 Other 9.2 16.7 Deferred Tax Liabilities 1,153.0 1,145.0 Net Deferred Income Tax Liability $ 603.9 $ 525.4 Deferred tax assets and liabilities are included within the consolidated financial statements as follows: 2017 2016 Deferred Tax Assets Other noncurrent assets $ 174.5 $ 185.0 Deferred Tax Liabilities Deferred income taxes 778.4 710.4 Net Deferred Income Tax Liability $ 603.9 $ 525.4 Gross federal tax credit carryforwards as of 30 September 2017 were $53.9 . The federal tax carryforwards have expiration periods between 2025 and 2027 . Gross state loss and tax credit carryforwards as of 30 September 2017 were $75.2 and $1.2 , respectively. The state tax carryforwards have expiration periods between 2024 and 2034 . Gross foreign loss and tax credit carryforwards as of 30 September 2017 were $247.3 and $21.0 , respectively. Foreign tax carryforwards of $221.7 have expiration periods between 2018 and 2027 ; the remainder have unlimited carryforward periods. The valuation allowance as of 30 September 2017 of $107.7 , primarily related to the tax benefit of foreign loss carryforwards of $52.4 as well as foreign capital assets of $49.1 that were generated from the loss recorded on the exit from the Energy-from-Waste business in 2016. If events warrant the reversal of the valuation allowance, it would result in a reduction of tax expense. We believe it is more likely than not that future earnings and reversal of deferred tax liabilities will be sufficient to utilize our deferred tax assets, net of existing valuation allowance, at 30 September 2017 . The reduction in the valuation allowances and tax loss carryforwards in 2017 was primarily due to the gain on sale of the PMD business, which resulted in the utilization of federal capital loss carryforwards as well as certain state loss carryforward balances from the prior year. See Note 3 , Discontinued Operations , for additional information. This reduction was offset in part by an increase in foreign tax loss carryforwards. Retirement benefits and compensation accruals are impacted significantly by the changes in plan assets and benefit obligation that have been recognized in other comprehensive income. See Note 16 , Retirement Benefits , for additional information. The repayment of a Eurobond of €300 million ( $317.2 ) that matured on 15 March 2017, resulted in a significant reduction of the deferred tax liabilities related to currency gains. We record U.S. income taxes on the undistributed earnings of our foreign subsidiaries and corporate joint ventures unless those earnings are indefinitely reinvested outside of the U.S. These cumulative undistributed earnings that are considered to be indefinitely reinvested in foreign subsidiaries and corporate joint ventures are included in retained earnings on the consolidated balance sheets and amounted to $6,032.5 as of 30 September 2017 . An estimated $1,443.9 in U.S. income and foreign withholding taxes would be due if these earnings were remitted as dividends after payment of all deferred taxes. A reconciliation of the beginning and ending amount of the unrecognized tax benefits is as follows: Unrecognized Tax Benefits 2017 2016 2015 Balance at beginning of year $ 90.2 $ 83.8 $ 93.1 Additions for tax positions of the current year 47.5 12.5 4.7 Additions for tax positions of prior years 16.1 2.9 3.0 Reductions for tax positions of prior years (4.0 ) — (2.2 ) Settlements (2.0 ) (5.6 ) (.6 ) Statute of limitations expiration (3.2 ) (2.9 ) (8.3 ) Foreign currency translation 1.8 (.5 ) (5.9 ) Balance at End of Year $ 146.4 $ 90.2 $ 83.8 At 30 September 2017 and 2016 , we had $146.4 and $90.2 of unrecognized tax benefits, excluding interest and penalties, of which $73.8 and $46.5 , respectively, would impact the effective tax rate if recognized. Interest and penalties related to unrecognized tax benefits are recorded as a component of income tax expense and totaled $3.7 in 2017 , $1.8 in 2016 , and $(1.9) in 2015 . Our accrued balance for interest and penalties was $12.1 and $8.4 as of 30 September 2017 and 2016 , respectively. The additions to unrecognized tax benefits in 2017 include unrecognized tax positions of $34.1 in various jurisdictions related to the sale of the PMD business and the spin-off of the EMD business. See Note 3, Discontinued Operations, and Note 4, Materials Technologies Separation, for additional information. We are currently under examination in a number of tax jurisdictions, some of which may be resolved in the next twelve months. As a result, it is reasonably possible that a change in the unrecognized tax benefits may occur during the next twelve months. However, quantification of an estimated range cannot be made at this time. We generally remain subject to examination in the following major tax jurisdictions for the years indicated below: Major Tax Jurisdiction Open Tax Years North America United States 2011-2017 Canada 2013-2017 Europe France 2014-2017 Germany 2012-2017 Netherlands 2012-2017 Spain 2011-2017 United Kingdom 2014-2017 Asia China 2012-2017 South Korea 2010-2017 Taiwan 2012-2017 Latin America Chile 2013-2017

Supplemental Information

Supplemental Information	12 Months Ended
	Sep. 30, 2017
Supplemental Information [Abstract]
Supplemental Information	23 . SUPPLEMENTAL INFORMATION Other Receivables and Current Assets 30 September 2017 2016 Derivative instruments $ 93.9 $ 169.3 Other receivables 188.0 181.7 Current capital lease receivables 93.3 88.2 Prepaid inventory — 92.8 Other 28.1 6.2 Other receivables and current assets $ 403.3 $ 538.2 Other Noncurrent Assets 30 September 2017 2016 Derivative instruments $ 133.9 $ 204.4 Other long-term receivables 82.1 16.9 Prepaid tax 5.1 37.0 Deferred tax assets 174.5 185.0 Pension benefits 18.4 — Deposits 34.8 36.5 Other 193.0 191.2 Other noncurrent assets $ 641.8 $ 671.0 Payables and Accrued Liabilities 30 September 2017 2016 Trade creditors $ 659.5 $ 578.8 Customer advances 438.9 371.2 Accrued payroll and employee benefits 187.1 217.1 Pension and postretirement benefits 22.6 35.5 Dividends payable 207.5 186.9 Outstanding payments in excess of certain cash balances 4.5 11.9 Accrued interest expense 42.2 47.9 Derivative instruments 95.9 73.5 Severance and other costs associated with business restructuring and cost reduction actions 41.5 15.7 Other 114.6 113.7 Payables and accrued liabilities $ 1,814.3 $ 1,652.2 Other Noncurrent Liabilities 30 September 2017 2016 Pension benefits $ 703.8 $ 1,155.1 Postretirement benefits 57.0 74.9 Other employee benefits 99.3 104.1 Contingencies related to uncertain tax positions 130.6 78.0 Advance payments 39.0 43.8 Environmental liabilities 72.3 70.3 Derivative instruments 36.0 21.8 Asset retirement obligations 144.0 116.1 Obligation for future contribution to an equity affiliate 94.4 94.4 Obligations associated with EfW 65.3 — Other 170.2 58.0 Other noncurrent liabilities $ 1,611.9 $ 1,816.5 Other Income (Expense), Net 30 September 2017 2016 2015 Technology and royalty income $ 20.8 $ 19.0 $ 22.8 Interest income (A) 1.5 6.1 4.2 Foreign exchange 4.3 (7.2 ) (22.6 ) Sale of assets and investments 24.3 8.8 36.3 Contract settlements 14.3 12.6 — Transition service agreements reimbursement (B) 38.4 — — Other 17.4 10.1 4.8 Other income (expense), net $ 121.0 $ 49.4 $ 45.5 (A) Beginning in the second quarter of fiscal year 2017, interest income associated with our short-term investments is reflected on the consolidated income statements in "Other non-operating income (expense), net." (B) Reflects reimbursement for costs in support of transition services agreements with Versum for EMD and with Evonik for PMD. Refer to Note 4 , Materials Technologies Separation , for additional information. Gain on Land Sales During the fourth quarter of 2017, we sold a parcel of land resulting in a gain of $12.2 . During the fourth quarter of 2015, we sold two parcels of land resulting in a gain of $33.6 . The gains are reflected in sale of assets and investments in the table above. Redeemable Noncontrolling Interest In July 2015, we completed the purchase of an additional 30.5% equity interest in our Indura S.A. subsidiary for $277.9 . We currently have a 97.8% controlling equity interest in Indura S.A. As redeemable noncontrolling interest is not part of total equity, the impacts below are excluded from our consolidated statements of equity. The following is a summary of the changes in redeemable noncontrolling interest for the year ended 30 September 2015: Balance at 30 September 2014 $ 287.2 Net income 11.5 Dividends (2.0 ) Purchase of noncontrolling interest (277.9 ) Currency translation adjustment (18.8 ) Balance at 30 September 2015 $ —

Summary by Quarter (Unaudited)

Summary by Quarter (Unaudited)	12 Months Ended
	Sep. 30, 2017
Quarterly Financial Information Disclosure [Abstract]
Summary by Quarter (Unaudited)	24 . SUMMARY BY QUARTER (UNAUDITED) These tables summarize the unaudited results of operations for each quarter of 2017 and 2016 : 2017 Q1 Q2 Q3 Q4 Total Sales $ 1,882.5 $ 1,980.1 $ 2,121.9 $ 2,203.1 $ 8,187.6 Gross profit (A) 564.4 576.3 635.7 657.8 2,434.2 Business separation costs (B) 30.2 — — — 30.2 Business restructuring and cost reduction actions (C) 50.0 10.3 42.7 48.4 151.4 Pension settlement loss (D) — 4.1 5.5 .9 10.5 Goodwill and intangible asset impairment charge (E) — — 162.1 — 162.1 Gain on land sale (F) — — — 12.2 12.2 Operating income (A) 328.1 391.2 252.6 455.7 1,427.6 Equity affiliates' income (loss) 38.0 34.2 (36.9 ) (G) 44.8 80.1 (G) Income tax provision (benefit) 78.4 94.5 89.3 (1.3 ) (H) 260.9 (H) Net income 306.4 2,135.7 104.1 475.0 3,021.2 Net income attributable to Air Products Income from continuing operations 251.6 304.4 104.2 474.2 1,134.4 Income (Loss) from discontinued operations 48.2 1,825.6 (I) (2.3 ) (5.5 ) 1,866.0 (I) Net income attributable to Air Products 299.8 2,130.0 101.9 468.7 3,000.4 Basic Earnings Per Common Share Attributable to Air Products Income from continuing operations 1.16 1.40 .48 2.17 5.20 Income (Loss) from discontinued operations .22 8.38 (.01 ) (.02 ) 8.56 Net income attributable to Air Products 1.38 9.78 .47 2.15 13.76 Diluted Earnings Per Common Share Attributable to Air Products Income from continuing operations 1.15 1.39 .47 2.15 5.16 Income (Loss) from discontinued operations .22 8.31 (.01 ) (.02 ) 8.49 Net income attributable to Air Products 1.37 9.70 .46 2.13 13.65 Dividends declared per common share .86 .95 .95 .95 3.71 Market price per common share – High 150.45 149.46 147.66 152.26 Market price per common share – Low 129.00 133.63 134.09 141.88 2016 Q1 Q2 Q3 Q4 Total Sales $ 1,866.3 $ 1,777.4 $ 1,914.5 $ 1,945.5 $ 7,503.7 Gross profit (A) 570.4 564.4 594.3 598.0 2,327.1 Business separation costs (B) 12.0 7.4 9.5 21.7 50.6 Business restructuring and cost reduction actions (C) — 10.7 13.2 10.6 34.5 Pension settlement loss (D) — 2.0 1.0 2.1 5.1 Operating income (A) 372.5 371.6 394.6 391.0 1,529.7 Equity affiliates' income 33.3 32.3 42.1 39.3 147.0 Loss on extinguishment of debt (J) — — — 6.9 6.9 Income tax provision 96.4 93.5 (K) 145.9 (K) 96.8 (K) 432.6 (K) Net income (loss) 372.0 (465.5 ) 354.1 400.9 661.5 Net income attributable to Air Products Income from continuing operations 280.9 278.9 250.3 289.4 1,099.5 Income (Loss) from discontinued operations 82.7 (752.2 ) 96.5 104.6 (468.4 ) Net income (loss) attributable to Air Products 363.6 (473.3 ) 346.8 394.0 631.1 Basic Earnings Per Common Share Attributable to Air Products Income from continuing operations 1.30 1.29 1.16 1.33 5.08 Income (Loss) from discontinued operations .38 (3.48 ) .44 .48 (2.16 ) Net income (loss) attributable to Air Products 1.68 (2.19 ) 1.60 1.81 2.92 Diluted Earnings Per Common Share Attributable to Air Products Income from continuing operations 1.29 1.28 1.15 1.32 5.04 Income (Loss) from discontinued operations .38 (3.45 ) .44 .48 (2.15 ) Net income (loss) attributable to Air Products 1.67 (2.17 ) 1.59 1.80 2.89 Dividends declared per common share .81 .86 .86 .86 3.39 Market price per common share – High 133.78 136.88 141.53 146.82 Market price per common share – Low 117.80 106.63 124.78 127.72 (A) Changes in estimates on projects accounted for under the percentage of completion method favorably impacted income by approximately $27 in fiscal year 2017 and $20 in fiscal year 2016 , primarily during the fourth quarter. For additional information, see Note 1 , Major Accounting Policies (Revenue Recognition). (B) For additional information, see Note 4 , Materials Technologies Separation . (C) For additional information, see Note 5 , Business Restructuring and Cost Reduction Actions . (D) For additional information, see Note 16 , Retirement Benefits . (E) For additional information, see Note 10 , Goodwill , and Note 11 , Intangible Assets . (F) The gain is reflected on the consolidated income statements in "Other income (expense), net." For additional information, see Note 23 , Supplemental Information . (G) Includes the impact of an other-than-temporary impairment of an investment in an equity affiliate. For additional information, see Note 8 , Summarized Financial Information of Equity Affiliates . (H) Includes the impact of a tax election benefit related to a non-U.S. subsidiary. For additional information, see Note 22 , Income Taxes . (I) Includes the after-tax gain on the sale of PMD. For additional information, see Note 3 , Discontinued Operations . (J) For additional information, see Note 15 , Debt . (K) Includes income tax expense for tax costs associated with business separation. For additional information, see Note 4 , Materials Technologies Separation .

Business Segment and Geographic

Business Segment and Geographic Information	12 Months Ended
	Sep. 30, 2017
Segment Reporting [Abstract]
Business Segment and Geographic Information	25 . BUSINESS SEGMENT AND GEOGRAPHIC INFORMATION Our reporting segments reflect the manner in which our chief operating decision maker reviews results and allocates resources. Except in the Corporate and other segment, each reporting segment meets the definition of an operating segment and does not include the aggregation of multiple operating segments. Our liquefied natural gas (LNG) and helium storage and distribution sale of equipment businesses are aggregated within the Corporate and other segment. Our reporting segments are: • Industrial Gases – Americas • Industrial Gases – EMEA (Europe, Middle East, and Africa) • Industrial Gases – Asia • Industrial Gases – Global • Corporate and other Industrial Gases – Regional The regional Industrial Gases segments (Americas, EMEA, and Asia) include the results of our regional industrial gas businesses, which produce and sell atmospheric gases such as oxygen, nitrogen, and argon (primarily recovered by the cryogenic distillation of air) and process gases such as hydrogen, carbon monoxide, helium, syngas, and specialty gases. We supply gases to customers in many industries, including those in metals, glass, chemical processing, energy production and refining, food processing, metallurgical industries, medical, and general manufacturing. We distribute gases to our customers through a variety of supply modes including liquid or gaseous bulk supply delivered by tanker or tube trailer and, for smaller customers, packaged gases delivered in cylinders and dewars or small on-sites (cryogenic or non-cryogenic generators). For large-volume customers, we construct an on-site plant adjacent to or near the customer’s facility or deliver product from one of our pipelines. We are the world’s largest provider of hydrogen, which is used by refiners to facilitate the conversion of heavy crude feedstock and lower the sulfur content of gasoline and diesel fuels. Electricity is the largest cost component in the production of atmospheric gases, and natural gas is the principal raw material for hydrogen, carbon monoxide, and syngas production. We mitigate energy and natural gas prices contractually through pricing formulas, surcharges, and cost pass-through arrangements. The regional Industrial Gases segments also include our share of the results of several joint ventures accounted for by the equity method. The largest of these joint ventures operate in Mexico, Italy, South Africa, India, Saudi Arabia, and Thailand. Each of the regional Industrial Gases segments competes against global industrial gas companies as well as regional competitors. Competition is based primarily on price, reliability of supply, and the development of industrial gas applications. We derive a competitive advantage in locations where we have pipeline networks, which enable us to provide reliable and economic supply of products to larger customers. Industrial Gases – Global The Industrial Gases – Global segment includes cryogenic and gas processing equipment sales for air separation. The equipment is sold worldwide to customers in a variety of industries, including chemical and petrochemical manufacturing, oil and gas recovery and processing, and steel and primary metals processing. The Industrial Gases – Global segment also includes centralized global costs associated with management of all the Industrial Gases segments. These costs include Industrial Gases global administrative costs, product development costs, and research and development costs. We compete with a large number of firms for all the offerings included in the Industrial Gases – Global segment. Competition in the equipment businesses is based primarily on technological performance, service, technical know-how, price, and performance guarantees. Corporate and other The Corporate and other segment includes two ongoing global businesses (our LNG equipment business and our liquid helium and liquid hydrogen transport and storage container businesses), and corporate support functions that benefit all the segments. Competition for the two sale of equipment businesses is based primarily on technological performance, service, technical know-how, price, and performance guarantees. Corporate and other also includes income and expense that is not directly associated with the business segments, including foreign exchange gains and losses and stranded costs. Stranded costs result from functional support previously provided to the two divisions comprising the former Materials Technologies segment. The majority of these costs are reimbursed to Air Products pursuant to short-term transition services agreements under which Air Products provides transition services to Versum for EMD and to Evonik for PMD. The reimbursement for costs in support of the transition services has been reflected on the consolidated income statements within “Other income (expense), net.” Refer to Note 4 , Materials Technologies Separation , for additional information. Also included are LIFO inventory adjustments, as the business segments use FIFO, and the LIFO pool adjustments are not allocated to the business segments. In addition to assets of the global businesses included in this segment, other assets include cash, deferred tax assets, and financial instruments. Customers We do not have a homogeneous customer base or end market, and no single customer accounts for more than 10% of our consolidated revenues. Accounting Policies The accounting policies of the segments are the same as those described in Note 1 , Major Accounting Policies . We evaluate the performance of segments based upon reported segment operating income. Business Segment Industrial Gases– Americas Industrial Gases– EMEA Industrial Gases– Asia Industrial Gases– Global Corporate and other Segment Total 2017 Sales to external customers $ 3,637.0 $ 1,780.4 $ 1,964.7 $ 722.9 $ 82.6 $ 8,187.6 Operating income (loss) 950.6 387.1 531.2 71.3 (170.6 ) 1,769.6 Depreciation and amortization 464.4 177.1 203.2 8.9 12.2 865.8 Equity affiliates' income 58.1 47.1 53.5 .9 — 159.6 Expenditures for long-lived assets 427.2 143.2 337.8 25.6 105.9 1,039.7 Investments in net assets of and advances to equity affiliates 287.5 508.6 471.8 19.0 — 1,286.9 Total assets 5,840.8 3,276.1 4,412.1 279.6 4,648.4 18,457.0 2016 Sales to external customers $ 3,344.1 $ 1,704.4 $ 1,720.4 $ 498.8 $ 236.0 $ 7,503.7 Operating income (loss) 893.2 384.6 451.0 (21.3 ) (87.6 ) 1,619.9 Depreciation and amortization 443.6 185.7 197.9 7.9 19.5 854.6 Equity affiliates' income 52.7 36.5 57.8 — — 147.0 Expenditures for long-lived assets 406.6 159.5 313.3 6.0 22.3 907.7 Investments in net assets of and advances to equity affiliates 250.6 580.5 442.5 10.0 — 1,283.6 Total assets 5,896.7 3,178.6 4,232.7 367.6 2,384.5 16,060.1 2015 Sales to external customers $ 3,694.5 $ 1,866.4 $ 1,661.3 $ 286.7 $ 315.4 $ 7,824.3 Operating income (loss) 806.1 331.3 389.3 (51.6 ) (86.5 ) 1,388.6 Depreciation and amortization 417.5 194.3 209.9 16.5 20.3 858.5 Equity affiliates' income (loss) 64.6 42.4 46.1 (.8 ) — 152.3 Expenditures for long-lived assets 414.5 215.6 402.5 94.8 35.0 1,162.4 Investments in net assets of and advances to equity affiliates 249.7 564.1 421.7 14.3 — 1,249.8 Total assets 5,782.5 3,324.1 4,159.1 370.5 1,123.8 14,760.0 Below is a reconciliation of segment total operating income to consolidated operating income: Operating Income 2017 2016 2015 Segment total $ 1,769.6 $ 1,619.9 $ 1,388.6 Business separation costs (30.2 ) (50.6 ) (7.5 ) Business restructuring and cost reduction actions (151.4 ) (34.5 ) (180.1 ) Pension settlement loss (10.5 ) (5.1 ) (19.3 ) Goodwill and intangible asset impairment charge (162.1 ) — — Gain on previously held equity interest — — 17.9 Gain on land sales (A) 12.2 — 33.6 Consolidated Total $ 1,427.6 $ 1,529.7 $ 1,233.2 (A) Reflected on the consolidated income statements in “Other income (expense), net.” Below is a reconciliation of segment total equity affiliates' income to consolidated equity affiliates' income : Equity Affiliates' Income 2017 2016 2015 Segment total $ 159.6 $ 147.0 $ 152.3 Equity method investment impairment charge (79.5 ) — — Consolidated Total $ 80.1 $ 147.0 $ 152.3 Below is a reconciliation of segment total assets to consolidated total assets: Total Assets 2017 2016 2015 Segment total $ 18,457.0 $ 16,060.1 $ 14,760.0 Discontinued operations 10.2 1,968.5 2,556.6 Consolidated Total $ 18,467.2 $ 18,028.6 $ 17,316.6 The sales information noted above relates to external customers only. All intersegment sales are eliminated in consolidation. The Industrial Gases – Global segment had intersegment sales of $239.0 in 2017 , $232.4 in 2016 , and $242.8 in 2015 . These sales are generally transacted at market pricing. For all other segments, intersegment sales are not material for all periods presented. Equipment manufactured for our regional industrial gases segments are generally transferred at cost and not reflected as an intersegment sale. Geographic Information Sales to External Customers 2017 2016 2015 United States $ 2,886.8 $ 2,911.7 $ 3,369.8 Europe, including Middle East 2,478.5 2,186.5 1,989.2 Asia, excluding China and India 849.6 721.4 736.8 China 1,143.4 1,020.4 957.8 Other (A) 829.3 663.7 770.7 Total $ 8,187.6 $ 7,503.7 $ 7,824.3 Long-Lived Assets (B) 2017 2016 2015 United States $ 3,407.4 $ 3,411.4 $ 3,502.9 Europe, including Middle East 1,279.0 1,292.5 1,379.8 Asia, excluding China and India 778.5 707.0 627.1 China 1,737.9 1,675.8 1,682.8 Other (A) 1,237.4 1,173.0 1,044.7 Total $ 8,440.2 $ 8,259.7 $ 8,237.3 (A) Includes Canada, Latin America, and India. (B) Long-lived assets include plant and equipment, net. Geographic information is based on country of origin. Included in United States revenues are export sales to third‑party customers of $64.2 in 2017 , $134.9 in 2016 , and $231.5 in 2015 .

Schedule II Valuation and Quali

Schedule II Valuation and Qualifying Accounts	12 Months Ended
	Sep. 30, 2017
Valuation and Qualifying Accounts [Abstract]
Schedule II - Valuation and Qualifying Accounts	SCHEDULE II–VALUATION AND QUALIFYING ACCOUNTS For the Years Ended 30 September 2017, 2016, and 2015 Balance at Beginning of Period Additions Charged to Expense Additions Charged to Other Accounts Other Changes (A) Balance at End of Period Year Ended 30 September 2017 Allowance for doubtful accounts $55 $7 $39 ($7 ) $94 Allowance for deferred tax assets (B) 165 6 7 (70 ) 108 Year Ended 30 September 2016 Allowance for doubtful accounts $48 $9 $13 ($15 ) $55 Allowance for deferred tax assets (C) 112 1 52 — 165 Year Ended 30 September 2015 Allowance for doubtful accounts $58 $8 $18 ($36 ) $48 Allowance for deferred tax assets 106 — 9 (3 ) 112 (A) Other changes related to allowance for doubtful accounts primarily includes write-offs of uncollectible trade receivables, net of recoveries. Other Changes also includes the impact of foreign currency translation adjustments. (B) The decrease in the valuation allowance was primarily due to the utilization of federal and state loss carryforwards as a result of recognizing the gain on the sale of our PMD business. This benefit was recorded in discontinued operations. See Note 3, Discontinued Operations, for additional information. (C) The increase in the valuation allowance was primarily due to the loss recorded on the exit from the Energy-from-Waste business. These costs were recorded in discontinued operations. See Note 3 , Discontinued Operations , for additional information.

Major Accounting Policies (Poli

Major Accounting Policies (Policies)	12 Months Ended
	Sep. 30, 2017
Accounting Policies [Abstract]
Basis of Presentation and Consolidation Principles	Basis of Presentation and Consolidation Principles The accompanying consolidated financial statements of Air Products and Chemicals, Inc. were prepared in accordance with accounting principles generally accepted in the United States of America (“U.S. GAAP”) and include the accounts of Air Products and Chemicals, Inc. and those of its controlled subsidiaries (“we,” “our,” “us,” the “Company,” “Air Products,” or “registrant”), which are generally majority owned. Intercompany transactions and balances are eliminated in consolidation. We consolidate all entities that we control. The general condition for control is ownership of a majority of the voting interests of an entity. Control may also exist in arrangements where we are the primary beneficiary of a variable interest entity (VIE). An entity that has both the power to direct the activities that most significantly impact the economic performance of a VIE and the obligation to absorb the losses or receive the benefits significant to the VIE is considered the primary beneficiary of that entity. We have determined that we are not a primary beneficiary in any material VIE.
Reclassifications	Reclassifications The results of the divisions comprising the former Materials Technologies segment and the former Energy‑from‑Waste segment have been presented as discontinued operations. Refer to Note 3 , Discontinued Operations , for additional details. The results of operations and cash flows of these businesses have been removed from the results of continuing operations and segment results for all periods presented. The assets and liabilities of the discontinued operations have been reclassified and are segregated in the consolidated balance sheets. The comprehensive income related to these businesses has not been segregated and is included in the consolidated comprehensive income statement for all periods presented. The notes to the consolidated financial statements, unless otherwise indicated, are on a continuing operations basis. The term "total company" includes both continuing and discontinued operations. The consolidated financial statements and accompanying notes reflect accounting guidance that was adopted during fiscal year 2017 . Refer to Note 2 , New Accounting Guidance , for additional information. Certain prior year information has been reclassified to conform to the fiscal year 2017 presentation.
Estimates and Assumptions	Estimates and Assumptions The preparation of the financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect amounts reported in the financial statements and accompanying notes. Actual results could differ from those estimates.
Revenue Recognition	Revenue Recognition Revenue from product sales is recognized as risk and title to the product transfer to the customer (which generally occurs at the time shipment is made), the sales price is fixed or determinable, and collectability is reasonably assured. Sales returns and allowances are not a business practice in the industry. Revenue from equipment sale contracts is recorded primarily using the percentage-of-completion method. Under this method, revenue from the sale of major equipment, such as liquefied natural gas (LNG) heat exchangers and large air separation units, is recognized based on costs or labor hours incurred to date compared with total estimated costs or labor hours to be incurred. When adjustments in estimated total contract revenues or estimated total costs or labor hours are required, any changes in the estimated profit from prior estimates are recognized in the current period for the inception-to-date effect of such change. Changes in estimates on projects accounted for under the percentage-of-completion method favorably impacted operating income by approximately $27 in fiscal year 2017 and approximately $20 in fiscal year 2016 . Our changes in estimates would not have significantly impacted amounts recorded in prior years. Changes in estimates during fiscal year 2015 were not significant. Certain contracts associated with facilities that are built to provide product to a specific customer are required to be accounted for as leases. In cases where operating lease treatment is appropriate, there is no difference in revenue recognition over the life of the contract as compared to accounting for the contract as product sales. In cases where capital lease treatment is appropriate, the timing of revenue and expense recognition is impacted. Revenue and expense are recognized up front for the sale of equipment component of the contract as compared to revenue recognition over the life of the arrangement under contracts not qualifying as capital leases. Additionally, a portion of the revenue representing interest income from the financing component of the lease receivable is reflected as sales over the life of the contract. Allowances for credit losses associated with capital lease receivables are recorded using the specific identification method. As of 30 September 2017 and 2016 , the credit quality of capital lease receivables did not require a material allowance for credit losses. If an arrangement involves multiple deliverables, the delivered items are considered separate units of accounting if the items have value on a stand-alone basis. Revenues are allocated to each deliverable based upon relative selling prices derived from company specific evidence. Amounts billed for shipping and handling fees are classified as sales in the consolidated income statements. Amounts billed for sales and use taxes, value-added taxes, and certain excise and other specific transactional taxes imposed on revenue-producing transactions are presented on a net basis and excluded from sales in the consolidated income statements. We record a liability until remitted to the respective taxing authority.
Cost of Sales	Cost of Sales Cost of sales predominantly represents the cost of tangible products sold. These costs include labor, raw materials, plant engineering, power, depreciation, production supplies and materials packaging costs, and maintenance costs. Costs incurred for shipping and handling are also included in cost of sales.
Depreciation	Depreciation Depreciation is recorded using the straight-line method, which deducts equal amounts of the cost of each asset from earnings every year over its expected economic useful life. The principal lives for major classes of plant and equipment are summarized in Note 9 , Plant and Equipment, net .
Selling and Administrative	Selling and Administrative The principal components of selling and administrative expenses are compensation, advertising, and promotional costs. Selling and administrative expenses also include costs for functional support previously provided to EMD and PMD and in support of transition services agreements with Versum and with Evonik, for which the reimbursement is reflected in "Other income (expense), net" on our consolidated income statements.
Postemployment Benefits	Postemployment Benefits We provide termination benefits to employees as part of ongoing benefit arrangements and record a liability for termination benefits when probable and estimable. These criteria are met when management, with the appropriate level of authority, approves and commits to its plan of action for termination; the plan identifies the employees to be terminated and their related benefits; and the plan is to be completed within one year. We do not provide material one-time benefit arrangements.
Fair Value Measurements	Fair Value Measurements We are required to measure certain assets and liabilities at fair value, either upon initial measurement or for subsequent accounting or reporting. For example, fair value is used in the initial measurement of net assets acquired in a business combination; on a recurring basis in the measurement of derivative financial instruments; and on a nonrecurring basis when long-lived assets are written down to fair value when held for sale or determined to be impaired. Refer to Note 14 , Fair Value Measurements , for information on the methods and assumptions used in our fair value measurements.
Financial Instruments	Financial Instruments We address certain financial exposures through a controlled program of risk management that includes the use of derivative financial instruments. The types of derivative financial instruments permitted for such risk management programs are specified in policies set by management. Refer to Note 13 , Financial Instruments , for further detail on the types and use of derivative instruments into which we enter. Major financial institutions are counterparties to all of these derivative contracts. We have established counterparty credit guidelines and generally enter into transactions with financial institutions of investment grade or better. Management believes the risk of incurring losses related to credit risk is remote, and any losses would be immaterial to the consolidated financial results, financial condition, or liquidity. We recognize derivatives on the balance sheet at fair value. On the date the derivative instrument is entered into, we generally designate the derivative as either (1) a hedge of a forecasted transaction or of the variability of cash flows to be received or paid related to a recognized asset or liability (cash flow hedge), (2) a hedge of a net investment in a foreign operation (net investment hedge), or (3) a hedge of the fair value of a recognized asset or liability (fair value hedge). The following details the accounting treatment of our cash flow, fair value, net investment, and non-designated hedges: • Changes in the fair value of a derivative that is designated as and meets the cash flow hedge criteria are recorded in accumulated other comprehensive loss (AOCL) to the extent effective and then recognized in earnings when the hedged items affect earnings. • Changes in the fair value of a derivative that is designated as and meets all the required criteria for a fair value hedge, along with the gain or loss on the hedged asset or liability that is attributable to the hedged risk, are recorded in current period earnings. • Changes in the fair value of a derivative and foreign currency debt that are designated as and meet all the required criteria for a hedge of a net investment are recorded as translation adjustments in AOCL. • Changes in the fair value of a derivative that is not designated as a hedge are recorded immediately in earnings. We formally document the relationships between hedging instruments and hedged items, as well as our risk management objective and strategy for undertaking various hedge transactions. This process includes relating derivatives that are designated as fair value or cash flow hedges to specific assets and liabilities on the balance sheet or to specific firm commitments or forecasted transactions. We also formally assess, at the inception of the hedge and on an ongoing basis, whether derivatives are highly effective in offsetting changes in fair values or cash flows of the hedged item. If it is determined that a derivative is not highly effective as a hedge, or if a derivative ceases to be a highly effective hedge, we will discontinue hedge accounting with respect to that derivative prospectively.
Foreign Currency	Foreign Currency Since we do business in many foreign countries, fluctuations in currency exchange rates affect our financial position and results of operations. In most of our foreign operations, the local currency is considered the functional currency. Foreign subsidiaries translate their assets and liabilities into U.S. dollars at current exchange rates in effect at the end of the fiscal period. The gains or losses that result from this process are shown as translation adjustments in AOCL in the equity section of the balance sheet. The revenue and expense accounts of foreign subsidiaries are translated into U.S. dollars at the average exchange rates that prevail during the period. Therefore, the U.S. dollar value of these items on the income statement fluctuates from period to period, depending on the value of the dollar against foreign currencies. Some transactions are made in currencies different from an entity’s functional currency. Gains and losses from these foreign currency transactions are generally reflected in "Other income (expense), net" on our consolidated income statements as they occur.
Environmental Expenditures	Environmental Expenditures Accruals for environmental loss contingencies are recorded when it is probable that a liability has been incurred and the amount of loss can be reasonably estimated. Remediation costs are capitalized if the costs improve the Company’s property as compared with the condition of the property when originally constructed or acquired, or if the costs prevent environmental contamination from future operations. We expense environmental costs related to existing conditions resulting from past or current operations and from which no current or future benefit is discernible. The amounts charged to income from continuing operations related to environmental matters totaled $11.4 , $12.2 , and $11.8 in 2017 , 2016 , and 2015 , respectively. The measurement of environmental liabilities is based on an evaluation of currently available information with respect to each individual site and considers factors such as existing technology, presently enacted laws and regulations, and prior experience in remediation of contaminated sites. An environmental liability related to cleanup of a contaminated site might include, for example, a provision for one or more of the following types of costs: site investigation and testing costs, cleanup costs, costs related to soil and water contamination resulting from tank ruptures, post-remediation monitoring costs, and outside legal fees. These liabilities include costs related to other potentially responsible parties to the extent that we have reason to believe such parties will not fully pay their proportionate share. They do not take into account any claims for recoveries from insurance or other parties and are not discounted. As assessments and remediation progress at individual sites, the amount of projected cost is reviewed, and the liability is adjusted to reflect additional technical and legal information that becomes available. Management has an established process in place to identify and monitor the Company’s environmental exposures. An environmental accrual analysis is prepared and maintained that lists all environmental loss contingencies, even where an accrual has not been established. This analysis assists in monitoring the Company’s overall environmental exposure and serves as a tool to facilitate ongoing communication among the Company’s technical experts, environmental managers, environmental lawyers, and financial management to ensure that required accruals are recorded and potential exposures disclosed. Given inherent uncertainties in evaluating environmental exposures, actual costs to be incurred at identified sites in future periods may vary from the estimates. Refer to Note 17 , Commitments and Contingencies , for additional information on the Company’s environmental loss contingencies. The accruals for environmental liabilities are reflected in the consolidated balance sheets, primarily as part of other noncurrent liabilities.
Litigation	Litigation In the normal course of business, we are involved in legal proceedings. We accrue a liability for such matters when it is probable that a liability has been incurred and the amount of loss can be reasonably estimated. When only a range of possible loss can be established, the most probable amount in the range is accrued. If no amount within this range is a better estimate than any other amount within the range, the minimum amount in the range is accrued. The accrual for a litigation loss contingency includes estimates of potential damages and other directly related costs expected to be incurred. Refer to Note 17 , Commitments and Contingencies , for additional information on our current legal proceedings.
Share-Based Compensation	Share-Based Compensation We have various share-based compensation programs, which include deferred stock units, stock options, and restricted stock. We expense the grant-date fair value of these awards over the vesting period during which employees perform related services. Expense recognition is accelerated for retirement-eligible individuals who would meet the requirements for vesting of awards upon their retirement. Refer to Note 19, Share-Based Compensation, for information on the models and assumptions used to determine the grant-date fair value of our awards.
Income Taxes	Income Taxes We account for income taxes under the asset and liability method. Under this method, deferred tax assets and liabilities are recognized for the tax effects of temporary differences between the financial reporting and tax bases of assets and liabilities using enacted tax rates in effect for the year in which the differences are expected to be recovered or settled. A principal temporary difference results from the excess of tax depreciation over book depreciation because accelerated methods of depreciation and shorter useful lives are used for income tax purposes. The cumulative impact of a change in tax rates or regulations is included in income tax expense in the period that includes the enactment date. We recognize deferred tax assets net of existing valuation allowance to the extent we believe that these assets are more likely than not to be realized considering all available evidence. A tax benefit for an uncertain tax position is recognized when it is more likely than not that the position will be sustained upon examination based on its technical merits. This position is measured as the largest amount of tax benefit that is greater than 50% likely of being realized. Interest and penalties related to unrecognized tax benefits are recognized as a component of income tax expense. For additional information regarding our income taxes, refer to Note 22 , Income Taxes .
Other Non-Operating Income (Expense), net	Other Non-Operating Income (Expense), net Beginning in the second quarter of fiscal year 2017, other non-operating income (expense), net includes interest income associated with our cash and cash items and short-term investments. Interest income was included in "Other income (expense), net" in 2016 and 2015 . Interest income in previous periods was not material.
Cash and Cash Items	Cash and Cash Items Cash and cash items include cash, time deposits, treasury securities, and certificates of deposit acquired with an original maturity of three months or less.
Short-term investments	Short-term investments Short-term investments include time deposits with original maturities greater than three months and less than one year.
Trade Receivables,net	Trade Receivables, net Trade receivables comprise amounts owed to us through our operating activities and are presented net of allowances for doubtful accounts. The allowances for doubtful accounts represent estimated uncollectible receivables associated with potential customer defaults on contractual obligations. A provision for customer defaults is made on a general formula basis when it is determined that the risk of some default is probable and estimable but cannot yet be associated with specific customers. The assessment of the likelihood of customer defaults is based on various factors, including the length of time the receivables are past due, historical experience, and existing economic conditions. The allowance also includes amounts for certain customers where a risk of default has been specifically identified, considering factors such as the financial condition of the customer and customer disputes over contractual terms and conditions. Allowance for doubtful accounts were $93.5 and $55.3 as of fiscal year end 30 September 2017 and 2016 , respectively.
Inventories	Inventories Inventories are stated at the lower of cost or market. We write down our inventories for estimated obsolescence or unmarketable inventory based upon assumptions about future demand and market conditions. We utilize the last-in, first-out (LIFO) method for determining the cost of inventories in the United States for the Industrial Gases regional and global segments. Inventories for these segments outside of the United States are accounted for on the first-in, first-out (FIFO) method, as the LIFO method is generally not permitted in the foreign jurisdictions where these segments operate. At the business segment level, inventories are recorded at FIFO and the LIFO pool adjustments are not allocated to the business segments.
Equity Investments	Equity Investments The equity method of accounting is used when we exercise significant influence but do not have operating control, generally assumed to be 20% – 50% ownership. Under the equity method, original investments are recorded at cost and adjusted by our share of undistributed earnings or losses of these companies. Equity investments are reviewed for impairment whenever events or changes in circumstances indicate that the carrying amount of the investment may not be recoverable.
Plant and Equipment	Plant and Equipment Plant and equipment is stated at cost less accumulated depreciation. Construction costs, labor, and applicable overhead related to installations are capitalized. Expenditures for additions and improvements that extend the lives or increase the capacity of plant assets are capitalized. The costs of maintenance and repairs of plant and equipment are charged to expense as incurred. Fully depreciated assets are retained in the gross plant and equipment and accumulated depreciation accounts until they are removed from service. In the case of disposals, assets and related depreciation are removed from the accounts, and the net amounts, less proceeds from disposal, are included in income. Refer to Note 9 , Plant and Equipment, net , for further detail.
Computer Software	Computer Software We capitalize costs incurred to purchase or develop software for internal use. Capitalized costs include purchased computer software packages, payments to vendors/consultants for development and implementation or modification to a purchased package to meet our requirements, payroll and related costs for employees directly involved in development, and interest incurred while software is being developed. Capitalized computer software costs are reflected in "Plant and equipment, net" on the consolidated balance sheets and are depreciated over the estimated useful life of the software, generally a period of three to ten years.
Capitalized Interest	Capitalized Interest As we build new plant and equipment, we include in the cost of these assets a portion of the interest payments we make during the year. The amount of capitalized interest was $19.0 , $32.7 , and $49.1 in 2017 , 2016 , and 2015 , respectively.
Impairment of Long-Lived Assets	Impairment of Long-Lived Assets Long-lived assets are grouped for impairment testing at the lowest level for which there are identifiable cash flows that are largely independent of the cash flows of other assets and liabilities and are evaluated for impairment whenever events or changes in circumstances indicate that the carrying amount of an asset group may not be recoverable. We assess recoverability by comparing the carrying amount of the asset group to estimated undiscounted future cash flows expected to be generated by the asset group. If an asset group is considered impaired, the impairment loss to be recognized is measured as the amount by which the asset group’s carrying amount exceeds its fair value. Long-lived assets to be sold are reported at the lower of carrying amount or fair value less cost to sell.
Asset Retirement Obligations	Asset Retirement Obligations The fair value of a liability for an asset retirement obligation is recognized in the period in which it is incurred. The fair value of the liability is measured using discounted estimated cash flows and is adjusted to its present value in subsequent periods as accretion expense is recorded. The corresponding asset retirement costs are capitalized as part of the carrying amount of the related long-lived asset and depreciated over the asset’s useful life. Our asset retirement obligations are primarily associated with on-site long-term supply contracts, under which we have built a facility on land owned by the customer and are obligated to remove the facility at the end of the contract term. Our asset retirement obligations totaled $ 144.7 and $119.9 at 30 September 2017 and 2016 , respectively.
Goodwill	Goodwill Business combinations are accounted for using the acquisition method. The purchase price is allocated to the assets acquired and liabilities assumed based on their estimated fair market values. Any excess purchase price over the fair market value of the net assets acquired, including identified intangibles, is recorded as goodwill. Preliminary purchase price allocations are made at the date of acquisition and finalized when information needed to affirm underlying estimates is obtained, within a maximum allocation period of one year. Goodwill is subject to impairment testing at least annually. In addition, goodwill is tested more frequently if a change in circumstances or the occurrence of events indicates that potential impairment exists. Refer to Note 10 , Goodwill , for further detail.
Intangible Assets	Intangible Assets Intangible assets with determinable lives primarily consist of customer relationships, purchased patents and technology, and land use rights. The cost of intangible assets with determinable lives is amortized on a straight-line basis over the estimated period of economic benefit. No residual value is estimated for these intangible assets. Indefinite-lived intangible assets consist of trade names and trademarks. Indefinite-lived intangibles are subject to impairment testing at least annually. In addition, intangible assets are tested more frequently if a change in circumstances or the occurrence of events indicates that potential impairment exists. Customer relationships are generally amortized over periods of five to twenty-five years. Purchased patents and technology and other are generally amortized over periods of five to fifteen years. Land use rights, which are included in other intangibles, are generally amortized over a period of fifty years. Amortizable lives are adjusted whenever there is a change in the estimated period of economic benefit. Refer to Note 11 , Intangible Assets , for further detail.
Retirement Benefits	Retirement Benefits The cost of pension benefits is recognized over the employees’ service period. We use actuarial methods and assumptions in the valuation of defined benefit obligations and the determination of expense. Differences between actual and expected results or changes in the value of obligations and plan assets are not recognized in earnings as they occur but, rather, systematically and gradually over subsequent periods. Refer to Note 16 , Retirement Benefits , for disclosures related to our pension and other postretirement benefits.

Discontinued Operations (Tables

Discontinued Operations (Tables)	12 Months Ended
	Sep. 30, 2017
Discontinued Operations and Disposal Groups [Abstract]
Schedule of Operating Results and Assets and Liabilities of Discontinued Operation	The following table summarizes the carrying amount of the accrual for our actions to dispose of the EfW business at 30 September 2017 : Asset Actions Contract Actions/ Other Total Loss on disposal of business $ 913.5 $ 32.2 $ 945.7 Noncash expenses (913.5 ) — (913.5 ) Cash expenditures — (18.6 ) (18.6 ) Currency translation adjustment — (1.4 ) (1.4 ) 30 September 2016 $ — $ 12.2 $ 12.2 Loss on disposal of business 6.3 53.0 59.3 Noncash expenses (6.3 ) — (6.3 ) Cash expenditures — (1.4 ) (1.4 ) Currency translation adjustment — 7.3 7.3 Amount reflected in other noncurrent liabilities — (65.3 ) (65.3 ) 30 September 2017 $ — $ 5.8 $ 5.8 The loss on disposal was recorded as a component of discontinued operations. The amount reflected in other noncurrent liabilities primarily relates to land lease obligations and is recorded in continuing operations. The remaining accrual is reflected in current liabilities of discontinued operations. Summarized Financial Information of Discontinued Operations The following tables detail the businesses and major line items that comprise income from discontinued operations, net of tax, on the consolidated income statements: Total Performance Energy-from- Discontinued Year Ended 30 September 2017 Materials Waste (A) Operations Sales $ 254.8 $ — $ 254.8 Cost of sales 182.3 13.8 196.1 Selling and administrative 22.5 .7 23.2 Research and development 5.1 — 5.1 Other income (expense), net .3 (2.0 ) (1.7 ) Operating Income (Loss) 45.2 (16.5 ) 28.7 Equity affiliates’ income .3 — .3 Income (Loss) Before Taxes 45.5 (16.5 ) 29.0 Income tax benefit (B) (50.8 ) (5.7 ) (56.5 ) Income (Loss) From Operations of Discontinued Operations, net of tax 96.3 (10.8 ) 85.5 Gain (Loss) on Disposal, net of tax (C) 1,827.6 (47.1 ) 1,780.5 Income (Loss) From Discontinued Operations, net of tax $ 1,923.9 $ (57.9 ) $ 1,866.0 (A) The loss from operations of discontinued operations for EfW primarily relates to costs incurred for ongoing project exit activities, administrative costs, and land lease obligations. (B) As a result of the expected gain on sale of PMD, we released valuation allowances related to capital loss and net operating loss carryforwards primarily during the first quarter of 2017 that favorably impacted our income tax provision within discontinued operations by approximately $69 . (C) After-tax gain on sale of $1,827.6 includes expense for income tax reserves for uncertain tax positions of $28.0 gross ( $21.0 net) in various jurisdictions. Total Electronic Performance Energy-from- Discontinued Year Ended 30 September 2016 Materials Materials Waste (A) Operations Sales $ 961.6 $ 1,059.1 $ — $ 2,020.7 Cost of sales 521.6 704.5 24.6 1,250.7 Selling and administrative 87.7 76.6 2.8 167.1 Research and development 40.8 19.6 .9 61.3 Other income (expense), net 2.2 4.2 (12.7 ) (6.3 ) Operating Income (Loss) 313.7 262.6 (41.0 ) 535.3 Equity affiliates’ income .2 1.4 — 1.6 Interest expense .3 — — .3 Income (Loss) Before Taxes (B) 313.6 264.0 (41.0 ) 536.6 Income tax provision (benefit) 73.4 80.5 (3.4 ) 150.5 Income (Loss) From Operations of Discontinued Operations, net of tax 240.2 183.5 (37.6 ) 386.1 Loss on Disposal, net of tax — — (846.6 ) (846.6 ) Income (Loss) From Discontinued Operations, net of tax 240.2 183.5 (884.2 ) (460.5 ) Net Income Attributable to Noncontrolling Interests of Discontinued Operations 7.9 — — 7.9 Net Income (Loss) From Discontinued Operations $ 232.3 $ 183.5 $ (884.2 ) $ (468.4 ) (A) The loss from operations of discontinued operations for EfW primarily relates to project suspension costs, land lease obligations, and administrative costs. (B) In fiscal year 2016 , income before taxes from operations of discontinued operations attributable to Air Products was $527.1 . Total Electronic Performance Energy-from- Discontinued Year Ended 30 September 2015 Materials Materials Waste (A) Operations Sales $ 984.1 $ 1,086.5 $ — $ 2,070.6 Cost of sales 586.8 754.0 5.1 1,345.9 Selling and administrative 86.4 79.9 2.4 168.7 Research and development 37.5 23.2 1.7 62.4 Other income (expense), net (B) (18.5 ) (9.2 ) — (27.7 ) Operating Income (Loss) 254.9 220.2 (9.2 ) 465.9 Equity affiliates’ income 1.0 1.2 — 2.2 Interest expense .1 .6 — .7 Income (Loss) Before Taxes (C) 255.8 220.8 (9.2 ) 467.4 Income tax provision (benefit) 49.7 68.4 (2.4 ) 115.7 Income (Loss) From Discontinued Operations, net of tax 206.1 152.4 (6.8 ) 351.7 Net Income Attributable to Noncontrolling Interests of Discontinued Operations 7.1 — — 7.1 Net Income (Loss) From Discontinued Operations $ 199.0 $ 152.4 $ (6.8 ) $ 344.6 (A) The loss from operations of discontinued operations for EfW primarily relates to land lease obligations and administrative costs. (B) Primarily includes business restructuring and cost reduction actions. (C) In fiscal year 2015 , income before taxes from operations of discontinued operations attributable to Air Products was $458.9 . The following tables detail the businesses and major line items that comprise assets and liabilities of discontinued operations on the consolidated balance sheets: Total Performance Energy-from- Discontinued 30 September 2017 Materials Waste Operations Assets Current Assets Plant and equipment, net $ — $ 10.2 $ 10.2 Total Current Assets — 10.2 10.2 Total Assets $ — $ 10.2 $ 10.2 Liabilities Current Liabilities Payables and accrued liabilities $ 9.2 $ 6.5 $ 15.7 Total Current Liabilities 9.2 6.5 15.7 Total Liabilities $ 9.2 $ 6.5 $ 15.7 Total Electronic Performance Energy-from- Discontinued 30 September 2016 Materials Materials Waste Operations Assets Current Assets Cash and cash items $ 170.6 $ 37.5 $ — $ 208.1 Trade receivables, net 134.7 159.0 — 293.7 Inventories 138.1 226.8 — 364.9 Plant and equipment, net — — 18.2 18.2 Other receivables and current assets 34.5 5.6 1.2 41.3 Total Current Assets 477.9 428.9 19.4 926.2 Plant and equipment, net 296.5 296.5 — 593.0 Goodwill, net 180.0 125.0 — 305.0 Intangible assets, net 75.1 25.0 — 100.1 Other noncurrent assets 37.5 6.7 — 44.2 Total Noncurrent Assets 589.1 453.2 — 1,042.3 Total Assets $ 1,067.0 $ 882.1 $ 19.4 $ 1,968.5 Liabilities Current Liabilities Payables and accrued liabilities $ 85.8 $ 72.5 $ 19.0 $ 177.3 Accrued income taxes 22.7 6.0 — 28.7 Current portion of long-term debt 5.8 — — 5.8 Total Current Liabilities 114.3 78.5 19.0 211.8 Long-term debt 981.8 — — 981.8 Deferred income taxes 50.3 6.4 — 56.7 Other noncurrent liabilities 47.4 9.6 — 57.0 Total Noncurrent Liabilities 1,079.5 16.0 — 1,095.5 Total Liabilities $ 1,193.8 $ 94.5 $ 19.0 $ 1,307.3

Business Restructuring and Co38

Business Restructuring and Cost Reduction Actions (Tables)	12 Months Ended
	Sep. 30, 2017
Restructuring Charges [Abstract]
Summary of Carrying Amount of Accrual for Business Restructuring and Cost Reduction Actions	The following table summarizes the carrying amount of the accrual for cost reduction actions at 30 September 2017 : Severance and Other Benefits Asset Actions/Other Total 2016 Charge $ 34.5 $ — $ 34.5 Amount reflected in pension liability (.9 ) — (.9 ) Cash expenditures (21.6 ) — (21.6 ) Currency translation adjustment .3 — .3 30 September 2016 $ 12.3 $ — $ 12.3 2017 Charge 66.3 88.5 154.8 Noncash expenses — (84.2 ) (84.2 ) Amount reflected in pension liability (2.0 ) — (2.0 ) Amount reflected in other noncurrent liabilities — (2.2 ) (2.2 ) Cash expenditures (35.7 ) (1.2 ) (36.9 ) Currency translation adjustment (.3 ) — (.3 ) 30 September 2017 $ 40.6 $ .9 $ 41.5 The following table summarizes the carrying amount of the accrual for the business realignment and reorganization at 30 September 2017: Severance and Other Benefits Asset Actions/Other Total 2014 Charge $ 11.1 $ — $ 11.1 Cash expenditures (1.7 ) — (1.7 ) 30 September 2014 $ 9.4 $ — $ 9.4 2015 Charge 131.5 48.6 180.1 Amount reflected in pension liability (11.2 ) — (11.2 ) Noncash expenses — (40.2 ) (40.2 ) Cash expenditures (100.3 ) (1.2 ) (101.5 ) Currency translation adjustment (.4 ) — (.4 ) 30 September 2015 $ 29.0 $ 7.2 $ 36.2 Cash expenditures (28.6 ) (3.8 ) (32.4 ) Currency translation adjustment (.4 ) — (.4 ) 30 September 2016 $ — $ 3.4 $ 3.4 Accrual settlement — (3.4 ) (3.4 ) 30 September 2017 $ — $ — $ —

Inventories (Tables)

Inventories (Tables)	12 Months Ended
	Sep. 30, 2017
Inventory Disclosure [Abstract]
Schedule of Components of Inventories	The components of inventories are as follows: 30 September 2017 2016 Finished goods $ 120.0 $ 131.3 Work in process 15.7 18.3 Raw materials, supplies and other 223.0 117.1 Total FIFO Cost 358.7 266.7 Less: Excess of FIFO cost over LIFO cost (23.3 ) (11.7 ) Inventories $ 335.4 $ 255.0

Summarized Financial Informat40

Summarized Financial Information of Equity Affiliates (Tables)	12 Months Ended
	Sep. 30, 2017
Equity Method Investments and Joint Ventures [Abstract]
Schedule of Equity Method Investments	The summarized financial information below is on a combined 100% basis and has been compiled based on financial statements of the companies accounted for by the equity method. The amounts presented include the accounts of the following equity affiliates: Abdullah Hashim Industrial Gases & Equipment Co., Ltd. (25%); INOX Air Products Limited (50%); Air Products South Africa (Proprietary) Limited (50%); Jazan Gas Projects Company (25%); Bangkok Cogeneration Company Limited (49%); Kulim Industrial Gases Sdn. Bhd. (50%); Bangkok Industrial Gases Co., Ltd. (49%); Sapio Produzione Idrogeno Ossigeno S.r.l. (49%); Chengdu Air & Gas Products Ltd. (50%); Tecnologia en Nitrogeno S. de R.L. de C.V. (50%); Helios S.p.A. (49%); Tyczka Industrie-Gases GmbH (50%); High-Tech Gases (Beijing) Co., Ltd. (50%); WuXi Hi-Tech Gas Co., Ltd. (50%); INFRA Group (40%); and principally, other industrial gas producers. 30 September 2017 2016 Current assets $ 1,333.2 $ 1,436.7 Noncurrent assets 4,026.9 3,063.3 Current liabilities 666.8 694.8 Noncurrent liabilities 2,194.3 1,540.4 Year Ended 30 September 2017 2016 2015 Net sales $ 2,343.3 $ 2,271.6 $ 2,460.5 Sales less cost of sales 878.6 871.5 922.7 Operating income 509.5 482.1 512.4 Net income 343.5 334.1 343.5

Plant and Equipment, Net (Table

Plant and Equipment, Net (Tables)	12 Months Ended
	Sep. 30, 2017
Property, Plant and Equipment [Abstract]
Schedule of Major Classes of Plant and Equipment	The major classes of plant and equipment are as follows: 30 September Useful Life in years 2017 2016 Land $ 231.0 $ 202.9 Buildings 30 977.8 918.6 Production facilities (A) 10 to 20 13,577.1 12,391.9 Distribution and other machinery and equipment (B) 5 to 25 3,944.0 3,821.0 Construction in progress 817.9 1,325.8 Plant and equipment, at cost 19,547.8 18,660.2 Less: accumulated depreciation 11,107.6 10,400.5 Plant and equipment, net $ 8,440.2 $ 8,259.7 (A) Depreciable lives of production facilities related to long-term customer supply contracts are matched to the contract lives. (B) The depreciable lives for various types of distribution equipment are 10 to 25 years for cylinders, depending on the nature and properties of the product; 20 years for tanks; 7.5 years for customer stations; and 5 to 15 years for tractors and trailers.

Goodwill (Tables)

Goodwill (Tables)	12 Months Ended
	Sep. 30, 2017
Goodwill and Intangible Assets Disclosure [Abstract]
Schedule of Carrying Amount of Goodwill by Segment	Changes to the carrying amount of consolidated goodwill by segment are as follows: Industrial Gases– Americas Industrial Gases– EMEA Industrial Gases– Asia Industrial Gases– Global Total Goodwill, net at 30 September 2015 $ 297.6 $ 386.5 $ 133.1 $ 19.9 $ 837.1 Currency translation 11.5 (5.9 ) 2.1 .3 8.0 Goodwill, net at 30 September 2016 $ 309.1 $ 380.6 $ 135.2 $ 20.2 $ 845.1 Impairment loss (145.3 ) — — — (145.3 ) Acquisitions — 3.5 — — 3.5 Currency translation (.1 ) 18.3 — — 18.2 Goodwill, net at 30 September 2017 $ 163.7 $ 402.4 $ 135.2 $ 20.2 $ 721.5 30 September 2017 2016 2015 Goodwill, gross $ 1,138.7 $ 1,103.7 $ 1,080.8 Accumulated impairment losses (417.2 ) (258.6 ) (243.7 ) Goodwill, net $ 721.5 $ 845.1 $ 837.1

Intangible Assets (Tables)

Intangible Assets (Tables)	12 Months Ended
	Sep. 30, 2017
Goodwill and Intangible Assets Disclosure [Abstract]
Schedule Finite-Lived Intangible Assets	The table below provides details of acquired intangible assets: 30 September 2017 30 September 2016 Gross Accumulated Amortization/ Impairment Net Gross Accumulated Amortization/ Impairment Net Customer relationships $ 424.1 $ (142.3 ) $ 281.8 $ 400.6 $ (118.2 ) $ 282.4 Patents and technology 13.4 (10.6 ) 2.8 13.6 (10.1 ) 3.5 Other 73.4 (36.6 ) 36.8 73.0 (33.7 ) 39.3 Total finite-lived intangibles 510.9 (189.5 ) 321.4 487.2 (162.0 ) 325.2 Trade names and trademarks, indefinite-lived 67.8 (20.9 ) 46.9 66.2 (3.5 ) 62.7 Total Intangible Assets $ 578.7 $ (210.4 ) $ 368.3 $ 553.4 $ (165.5 ) $ 387.9
Schedule of Indefinite-Lived Intangible Assets	The table below provides details of acquired intangible assets: 30 September 2017 30 September 2016 Gross Accumulated Amortization/ Impairment Net Gross Accumulated Amortization/ Impairment Net Customer relationships $ 424.1 $ (142.3 ) $ 281.8 $ 400.6 $ (118.2 ) $ 282.4 Patents and technology 13.4 (10.6 ) 2.8 13.6 (10.1 ) 3.5 Other 73.4 (36.6 ) 36.8 73.0 (33.7 ) 39.3 Total finite-lived intangibles 510.9 (189.5 ) 321.4 487.2 (162.0 ) 325.2 Trade names and trademarks, indefinite-lived 67.8 (20.9 ) 46.9 66.2 (3.5 ) 62.7 Total Intangible Assets $ 578.7 $ (210.4 ) $ 368.3 $ 553.4 $ (165.5 ) $ 387.9
Schedule of Projected Annual Amortization Expense	Projected annual amortization expense for intangible assets as of 30 September 2017 is as follows: 2018 $ 22.1 2019 21.8 2020 21.6 2021 20.1 2022 17.4 Thereafter 218.4 Total $ 321.4

Leases (Tables)

Leases (Tables)	12 Months Ended
	Sep. 30, 2017
Leases [Abstract]
Schedule of Future Minimum Lease Payments for Capital Leases	At 30 September 2017 , minimum payments due under leases associated with continuing operations are as follows: Capital Leases Operating Leases 2018 $ 2.2 $ 56.6 2019 1.8 45.8 2020 1.6 35.2 2021 3.0 27.1 2022 1.5 22.9 Thereafter 19.9 126.6 Total $ 30.0 $ 314.2
Schedule of Future Minimum Rental Payments for Operating Leases	At 30 September 2017 , minimum payments due under leases associated with continuing operations are as follows: Capital Leases Operating Leases 2018 $ 2.2 $ 56.6 2019 1.8 45.8 2020 1.6 35.2 2021 3.0 27.1 2022 1.5 22.9 Thereafter 19.9 126.6 Total $ 30.0 $ 314.2
Schedule of Minimum Lease Payments to be Collected	At 30 September 2017 , minimum lease payments expected to be collected are as follows: 2018 $ 182.0 2019 176.4 2020 171.4 2021 165.5 2022 154.1 Thereafter 1,047.6 Total $ 1,897.0 The components of lease receivables were as follows: 30 September 2017 2016 Gross minimum lease payments receivable $ 1,897.0 $ 2,072.6 Unearned interest income (671.9 ) (762.7 ) Lease Receivables, net $ 1,225.1 $ 1,309.9

Financial Instruments (Tables)

Financial Instruments (Tables)	12 Months Ended
	Sep. 30, 2017
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Schedule of Notional Amounts of Outstanding Derivative Instruments	The following table summarizes our outstanding interest rate management contracts and cross currency interest rate swaps: 30 September 2017 30 September 2016 US$ Notional Average Pay % Average Receive % Years Average Maturity US$ Notional Average Pay % Average Receive % Years Average Maturity Interest rate swaps (fair value hedge) $ 600.0 LIBOR 2.28 % 1.3 $ 600.0 LIBOR 2.28 % 2.3 Cross currency interest rate swaps (net investment hedge) $ 539.7 3.27 % 2.59 % 1.9 $ 517.7 3.24 % 2.43 % 2.6 Cross currency interest rate swaps (cash flow hedge) $ 1,095.7 4.96 % 2.78 % 2.4 $ 1,088.9 4.77 % 2.72 % 3.3 Cross currency interest rate swaps (not designated) $ 41.6 3.28 % 2.32 % 1.7 $ 27.4 3.62 % .81 % 1.8 The table below summarizes our outstanding currency price risk management instruments: 30 September 2017 30 September 2016 US$ Notional Years Average Maturity US$ Notional Years Average Maturity Forward Exchange Contracts Cash flow hedges $ 3,150.2 .4 $ 4,130.3 .5 Net investment hedges 675.5 3.0 968.2 2.7 Not designated 273.8 .1 2,648.3 .4 Total Forward Exchange Contracts $ 4,099.5 .8 $ 7,746.8 .7
Schedule of Fair Value of Derivative Instruments	The table below summarizes the fair value and balance sheet location of our outstanding derivatives: Balance Sheet 30 September Balance Sheet 30 September Location 2017 2016 Location 2017 2016 Derivatives Designated as Hedging Instruments: Forward exchange contracts Other receivables $ 81.7 $ 72.3 Accrued liabilities $ 82.0 $ 44.0 Interest rate management contracts Other receivables 11.1 19.9 Accrued liabilities 10.7 — Forward exchange contracts Other noncurrent assets 27.1 44.4 Other noncurrent liabilities 13.8 9.1 Interest rate management contracts Other noncurrent assets 102.6 160.0 Other noncurrent 22.2 12.0 Total Derivatives Designated as Hedging Instruments $ 222.5 $ 296.6 $ 128.7 $ 65.1 Derivatives Not Designated as Hedging Instruments: Forward exchange contracts Other receivables 1.1 77.1 Accrued liabilities $ 2.2 $ 29.5 Interest rate management contracts Other receivables — — Accrued liabilities 1.0 — Interest rate management contracts Other noncurrent assets 4.2 — Other noncurrent — .7 Total Derivatives Not Designated as Hedging Instruments $ 5.3 $ 77.1 $ 3.2 $ 30.2 Total Derivatives $ 227.8 $ 373.7 $ 131.9 $ 95.3
Schedule of Gains and Losses Related to Derivative Instruments	The table below summarizes the gain or loss related to our cash flow hedges, fair value hedges, net investment hedges, and derivatives not designated as hedging instruments: Year Ended 30 September Forward Exchange Contracts Foreign Currency Debt Other (A) Total 2017 2016 2017 2016 2017 2016 2017 2016 Cash Flow Hedges, net of tax: Net gain (loss) recognized in OCI (effective portion) $ .3 $ 10.5 $ — $ — $ (12.9 ) $ 3.2 $ (12.6 ) $ 13.7 Net (gain) loss reclassified from OCI to sales/cost of sales (effective portion) 18.3 .2 — — — — 18.3 .2 Net (gain) loss reclassified from OCI to other income (expense), net (effective portion) (3.8 ) (25.7 ) — — 10.5 (20.3 ) 6.7 (46.0 ) Net (gain) loss reclassified from OCI to interest expense (effective portion) (2.1 ) 6.7 — — 2.9 3.3 .8 10.0 Net (gain) loss reclassified from OCI to other income (expense), net (ineffective portion) (1.6 ) (.2 ) — — — — (1.6 ) (.2 ) Fair Value Hedges: Net gain (loss) recognized in interest expense (B) $ — $ — $ — $ — $ (14.7 ) $ (8.8 ) $ (14.7 ) $ (8.8 ) Net Investment Hedges, net of tax: Net gain (loss) recognized in OCI $ (11.1 ) $ 17.4 $ (32.8 ) $ (9.6 ) $ (15.6 ) $ 35.0 $ (59.5 ) $ 42.8 Derivatives Not Designated as Hedging Instruments: Net gain (loss) recognized in other income (expense), net (C) $ 4.1 $ (1.8 ) $ — $ — $ (2.4 ) $ (1.6 ) $ 1.7 $ (3.4 ) (A) Other includes the impact on other comprehensive income (OCI) and earnings primarily related to interest rate and cross currency interest rate swaps. (B) The impact of fair value hedges noted above was largely offset by recognized gains and losses resulting from the impact of changes in related interest rates on outstanding debt. (C) The impact of the non-designated hedges noted above was largely offset by recognized gains and losses resulting from the impact of changes in exchange rates on assets and liabilities denominated in nonfunctional currencies.

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	12 Months Ended
	Sep. 30, 2017
Fair Value Disclosures [Abstract]
Schedule of Carrying Values and Fair Values of Financial Instruments	The carrying values and fair values of financial instruments were as follows: 30 September 2017 30 September 2016 Carrying Value Fair Value Carrying Value Fair Value Assets Derivatives Forward exchange contracts $ 109.9 $ 109.9 $ 193.8 $ 193.8 Interest rate management contracts 117.9 117.9 179.9 179.9 Liabilities Derivatives Forward exchange contracts $ 98.0 $ 98.0 $ 82.6 $ 82.6 Interest rate management contracts 33.9 33.9 12.7 12.7 Long-term debt, including current portion 3,818.8 3,928.2 4,275.1 4,474.0
Schedule of Fair Value of Assets and Liabilities Measured on Recurring Basis	The following table summarizes assets and liabilities measured at fair value on a recurring basis in the consolidated balance sheets: 30 September 2017 30 September 2016 Total Level 1 Level 2 Level 3 Total Level 1 Level 2 Level 3 Assets at Fair Value Derivatives Forward exchange contracts $ 109.9 $ — $ 109.9 $ — $ 193.8 $ — $ 193.8 $ — Interest rate management contracts 117.9 — 117.9 — 179.9 — 179.9 — Total Assets at Fair Value $ 227.8 $ — $ 227.8 $ — $ 373.7 $ — $ 373.7 $ — Liabilities at Fair Value Derivatives Forward exchange contracts $ 98.0 $ — $ 98.0 $ — $ 82.6 $ — $ 82.6 $ — Interest rate management contracts 33.9 — 33.9 — 12.7 — 12.7 — Total Liabilities at Fair Value $ 131.9 $ — $ 131.9 $ — $ 95.3 $ — $ 95.3 $ —
Schedule of Nonrecurring Fair Value Measurements	The following is a tabular presentation of nonrecurring fair value measurements along with the level within the fair value hierarchy in which the fair value measurement in its entirety falls: 31 December 2016 Total Level 1 Level 2 Level 3 2017 Loss 2016 Loss Plant and Equipment – Continuing operations (A) $ 1.4 $ — $ — $ 1.4 $ 45.7 $ — Plant and Equipment—Discontinued operations (A) $ 11.0 $ — $ — $ 11.0 $ 6.3 $ 913.5 (A) We assessed the recoverability of the carrying value of assets associated with the EfW discontinued operation, including the air separation unit within continuing operations of our Industrial Gases – EMEA segment. We based our estimates primarily on an orderly liquidation valuation which resulted in losses for the difference between the orderly liquidation value and net book value of the assets as of 31 December 2016 during fiscal year 2017. There have been no significant updates to our estimates as of 30 September 2017 . For additional information, see Note 3 , Discontinued Operations , and Note 5 , Business Restructuring and Cost Reduction Actions . 30 June 2017 2017 Loss Total Level 1 Level 2 Level 3 Investment in Equity Affiliate (A) $ 68.5 $ — $ — $ 68.5 $ 79.5 (A) We assessed the recoverability of the carrying value of our equity investment in AHG. We estimated the fair value of our investment using weighting of the results of the income and market approaches. An impairment loss was recognized for the difference between the carrying amount and the fair value of the investment as of 30 June 2017. There have been no updates to our estimates as of 30 September 2017 . For additional information, see Note 8 , Summarized Financial Information of Equity Affiliates .

Debt (Tables)

Debt (Tables)	12 Months Ended
	Sep. 30, 2017
Debt Disclosure [Abstract]
Schedule of Total Debt	The tables below summarize our outstanding debt at 30 September 2017 and 2016 : Total Debt 30 September 2017 2016 Short-term borrowings $ 144.0 $ 935.8 Current portion of long-term debt 416.4 365.4 Long-term debt 3,402.4 3,909.7 Total Debt $ 3,962.8 $ 5,210.9
Schedule of Short-term Borrowings	Short-term Borrowings 30 September 2017 2016 Bank obligations $ 144.0 $ 133.1 Commercial paper — 802.7 Total Short-term Borrowings $ 144.0 $ 935.8
Schedule of Long-term Debt Instruments	Long-term Debt 30 September Fiscal Year Maturities 2017 2016 Payable in U.S. Dollars Debentures 8.75% 2021 $ 18.4 $ 18.4 Medium-term Notes (weighted average rate) Series E 7.6% 2026 17.2 17.2 Senior Notes Note 1.2% 2018 400.0 400.0 Note 4.375% 2019 400.0 400.0 Note 3.0% 2022 400.0 400.0 Note 2.75% 2023 400.0 400.0 Note 3.35% 2024 400.0 400.0 Other (weighted average rate) Variable-rate industrial revenue bonds .87% 2035 to 2050 631.9 769.9 Other .89% 2018 to 2019 10.9 25.7 Payable in Other Currencies Eurobonds 4.625% 2017 — 337.0 Eurobonds 2.0% 2020 354.4 337.0 Eurobonds 1.0% 2025 354.4 337.0 Eurobonds .375% 2021 413.5 393.2 Other 4.3% 2018 to 2022 25.8 52.9 Capital Lease Obligations United States 5.0% 2018 .2 .5 Foreign 10.7% 2018 to 2036 10.6 9.7 Total Principal Amount 3,837.3 4,298.5 Less: Unamortized Discount and Debt Issuance Costs (18.5 ) (23.4 ) Total Long-term Debt 3,818.8 4,275.1 Less: Current portion of long-term debt (416.4 ) (365.4 ) Long-term Debt $ 3,402.4 $ 3,909.7
Schedule of Maturities of Long-term Debt	Maturities of long-term debt in each of the next five years and beyond are as follows: 2018 $ 416.4 2019 409.0 2020 356.1 2021 433.3 2022 401.0 Thereafter 1,821.5 Total $ 3,837.3

Retirement Benefits (Tables)

Retirement Benefits (Tables)	12 Months Ended
	Sep. 30, 2017
Defined Benefit Pension Plan
Schedule of Net Periodic Benefit Cost	The cost of our defined benefit pension plans included the following components: 2017 2016 2015 U.S. International U.S. International U.S. International Service cost $ 29.0 $ 25.9 $ 36.5 $ 24.3 $ 42.2 $ 31.3 Interest cost 107.5 32.2 110.7 44.3 124.7 57.8 Expected return on plan assets (207.7 ) (75.2 ) (202.0 ) (78.3 ) (202.0 ) (79.8 ) Amortization Net actuarial loss 88.7 54.7 85.3 35.6 78.9 41.4 Prior service cost 2.3 (.1 ) 2.8 (.2 ) 2.8 — Settlements 10.5 1.7 5.1 1.3 18.9 2.3 Curtailments 4.3 (1.3 ) — (1.1 ) 5.3 — Special termination benefits 2.8 .4 2.0 — 7.2 1.5 Other — 1.1 (.3 ) 2.1 1.0 2.1 Net Periodic Benefit Cost – Total $ 37.4 $ 39.4 $ 40.1 $ 28.0 $ 79.0 $ 56.6 Less: Discontinued Operations (.7 ) (4.1 ) (7.9 ) (4.4 ) (12.9 ) (7.7 ) Net Periodic Benefit Cost – Continuing Operations $ 36.7 $ 35.3 $ 32.2 $ 23.6 $ 66.1 $ 48.9
Schedule of Assumptions Used in The Calculation of Net Periodic Pension Cost and PBO	We calculate net periodic benefit cost for a given fiscal year based on assumptions developed at the end of the previous fiscal year. The following table sets forth the weighted average assumptions used in the calculation of net periodic benefit cost: 2017 2016 2015 U.S. International U.S. International U.S. International Discount rate (A) 3.5 % 2.0 % 4.3 % 3.3 % 4.3 % 3.6 % Expected return on plan assets 8.0 % 6.1 % 8.0 % 6.3 % 8.3 % 6.1 % Rate of compensation increase 3.5 % 3.5 % 3.5 % 3.5 % 3.5 % 3.6 % (A) Effective in 2016, the Company began to measure the service cost and interest cost components of pension expense by applying spot rates along the yield curve to the relevant projected cash flows, as we believe this provides a better measurement of these costs. The Company accounted for this in 2016 as a change in accounting estimate and, accordingly, accounted for it on a prospective basis. This change did not affect the measurement of the total benefit obligation. The 2017 discount rates used to measure the service cost and interest cost of our U.S. pension plans were 3.6% and 3.0% , respectively. The rates used to measure the service cost and interest cost of our major International pension plans were 2.1% and 1.8% , respectively. The previous method would have used a single discount rate for both service and interest costs. The projected benefit obligation (PBO) is the actuarial present value of benefits attributable to employee service rendered to date, including the effects of estimated future salary increases. The following table sets forth the weighted average assumptions used in the calculation of the PBO: 2017 2016 U.S. International U.S. International Discount rate 3.8 % 2.4 % 3.5 % 2.0 % Rate of compensation increase 3.5 % 3.6 % 3.5 % 3.5 %
Schedule of Changes in Projected Benefit Obligations	2017 2016 U.S. International U.S. International Change in Projected Benefit Obligation Obligation at beginning of year $ 3,477.7 $ 1,849.6 $ 3,139.9 $ 1,647.9 Service cost 29.0 25.9 36.5 24.3 Interest cost 107.5 32.2 110.7 44.3 Amendments 1.9 — 1.2 — Actuarial (gain) loss (68.0 ) (132.4 ) 380.2 376.4 Divestitures — (34.1 ) — — Curtailments (17.3 ) (4.2 ) (.4 ) (1.2 ) Settlement (gain) loss 7.0 — 5.4 (3.4 ) Special termination benefits 2.8 — 2.0 — Participant contributions — 1.4 — 1.6 Benefits paid (182.9 ) (46.5 ) (197.4 ) (46.6 ) Currency translation/other — 57.6 (.4 ) (193.7 ) Obligation at End of Year $ 3,357.7 $ 1,749.5 $ 3,477.7 $ 1,849.6
Schedule of Changes in Fair Value of Plan Assets	2017 2016 U.S. International U.S. International Change in Plan Assets Fair value at beginning of year $ 2,705.3 $ 1,411.1 $ 2,613.6 $ 1,302.8 Actual return on plan assets 319.6 87.9 275.2 273.2 Company contributions 27.2 42.2 13.9 65.4 Participant contributions — 1.4 — 1.6 Divestitures — (3.0 ) — — Benefits paid (182.9 ) (46.5 ) (197.4 ) (46.6 ) Settlements — (5.3 ) — (3.4 ) Currency translation/other — 52.2 — (181.9 ) Fair Value at End of Year $ 2,869.2 $ 1,540.0 $ 2,705.3 $ 1,411.1 Funded Status at End of Year $ (488.5 ) $ (209.5 ) $ (772.4 ) $ (438.5 )
Schedule of Amounts Recognized in Balance Sheet	Amounts Recognized Noncurrent assets $ 5.3 $ 13.1 $ — $ — Accrued liabilities (12.6 ) — (24.1 ) — Noncurrent liabilities (481.2 ) (222.6 ) (748.3 ) (438.5 ) Net Amount Recognized $ (488.5 ) $ (209.5 ) $ (772.4 ) $ (438.5 )
Schedule of Amounts Recognized in Other Comprehensive Income (Loss)	The changes in plan assets and benefit obligation that have been recognized in other comprehensive income on a pretax basis during 2017 and 2016 consist of the following: 2017 2016 U.S. International U.S. International Net actuarial (gain) loss arising during the period $ (189.8 ) $ (162.0 ) $ 311.8 $ 172.1 Amortization of net actuarial loss (103.3 ) (55.7 ) (90.4 ) (36.5 ) Prior service cost (credit) arising during the period 1.9 — 1.2 (.1 ) Amortization of prior service cost (2.3 ) .1 (2.8 ) .2 Total $ (293.5 ) $ (217.6 ) $ 219.8 $ 135.7
Schedule of Components Recognized in Accumulated Other Comprehensive Income on Pretax Basis	The components recognized in accumulated other comprehensive loss on a pretax basis at 30 September consisted of: 2017 2016 U.S. International U.S. International Net actuarial loss $ 980.5 $ 551.9 $ 1,273.6 $ 769.6 Prior service cost (credit) 8.1 (1.8 ) 8.5 (1.9 ) Net transition liability — .4 — .4 Total $ 988.6 $ 550.5 $ 1,282.1 $ 768.1
Schedule of Amounts in Accumulated Other Comprehensive Income (Loss) to be Recognized over Next Fiscal Year	The amount of accumulated other comprehensive loss at 30 September 2017 that is expected to be recognized as a component of net periodic pension cost during fiscal year 2018 , excluding discontinued operations and amounts that may be recognized through settlement losses, is as follows: U.S. International Net actuarial loss $ 88.5 $ 39.9 Prior service cost (credit) 1.5 (.1 )
Schedule of Benefit Obligations in Excess of Fair Value of Plan Assets	The following table provides information on pension plans where the benefit liability exceeds the value of plan assets: 30 September 2017 30 September 2016 U.S. International U.S. International Pension Plans with PBO in Excess of Plan Assets: PBO $ 3,116.7 $ 465.7 $ 3,477.7 $ 1,849.6 Fair value of plan assets 2,623.0 243.1 2,705.3 1,411.1 Pension Plans with ABO in Excess of Plan Assets: ABO $ 2,951.0 $ 365.6 $ 3,242.5 $ 1,673.6 Fair value of plan assets 2,623.0 197.1 2,705.3 1,370.1
Schedule of Target and Actual Asset Allocations by Category	2017 Target Allocation 2017 Actual Allocation 2016 Actual Allocation U.S. International U.S. International U.S. International Asset Category Equity securities 46-66% 46-57% 58 % 53 % 65 % 60 % Debt securities 32-42% 41-53% 34 % 46 % 28 % 38 % Real estate/other 0-10% 0-2% 7 % 1 % 7 % 1 % Cash — — 1 % — % — % 1 % Total 100 % 100 % 100 % 100 %
Schedule of Allocation of Plan Assets	The following table summarizes pension plan assets measured at fair value by asset class (see Note 14 , Fair Value Measurements , for definition of the levels): 30 September 2017 30 September 2016 Total Level 1 Level 2 Level 3 Total Level 1 Level 2 Level 3 U.S. Qualified Pension Plans Cash and cash equivalents $ 13.6 $ 13.6 $ — $ — $ 12.7 $ 12.7 $ — $ — Equity securities 598.6 598.6 — — 637.0 637.0 — — Equity mutual funds 276.5 276.5 — — 300.2 300.2 — — Equity pooled funds 787.0 — 787.0 — 815.5 — 815.5 — Fixed income: Bonds (government and corporate) 985.7 — 985.7 — 747.8 — 747.8 — Real estate pooled funds 207.8 — — 207.8 192.1 — — 192.1 Total U.S. Qualified Pension Plans $ 2,869.2 $ 888.7 $ 1,772.7 $ 207.8 $ 2,705.3 $ 949.9 $ 1,563.3 $ 192.1 International Pension Plans Cash and cash equivalents $ 7.3 $ 7.3 $ — $ — $ 6.6 $ 6.6 $ — $ — Equity pooled funds 821.4 — 821.4 — 854.8 — 854.8 — Fixed income pooled funds 651.3 — 651.3 — 486.9 — 486.9 — Other pooled funds 18.6 — 10.8 7.8 17.0 — 9.7 7.3 Insurance contracts 41.4 — — 41.4 45.8 — — 45.8 Total International Pension Plans $ 1,540.0 $ 7.3 $ 1,483.5 $ 49.2 $ 1,411.1 $ 6.6 $ 1,351.4 $ 53.1
Schedule of Effect of Significant Unobservable Inputs, Changes in Plan Assets	The following table summarizes changes in fair value of the pension plan assets classified as Level 3, by asset class: Real Estate Pooled Funds Other Pooled Funds Insurance Contracts Total 30 September 2015 $ 174.2 $ 6.6 $ 45.3 $ 226.1 Actual return on plan assets: Assets held at end of year 17.9 .1 3.2 21.2 Assets sold during the period — .3 — .3 Purchases, sales, and settlements, net — .3 (2.7 ) (2.4 ) 30 September 2016 $ 192.1 $ 7.3 $ 45.8 $ 245.2 Actual return on plan assets: Assets held at end of year 15.7 1.2 (1.0 ) 15.9 Assets sold during the period — .3 — .3 Purchases, sales, and settlements, net — (1.0 ) (3.4 ) (4.4 ) 30 September 2017 $ 207.8 $ 7.8 $ 41.4 $ 257.0
Schedule of Expected Benefit Payments	Projected benefit payments, which reflect expected future service, are as follows: U.S. International 2018 $ 158.5 $ 50.9 2019 163.4 53.4 2020 167.3 53.8 2021 171.4 56.8 2022 177.2 59.3 2023-2027 938.5 333.3
Other Postretirement Benefits Plan
Schedule of Net Periodic Benefit Cost	The cost of our other postretirement benefit plans includes the following components: 2017 2016 2015 Service cost $ 1.1 $ 2.2 $ 2.8 Interest cost 1.6 2.0 2.2 Amortization of net actuarial loss .2 .7 .8 Net Periodic Postretirement Cost $ 2.9 $ 4.9 $ 5.8 Less: Discontinued Operations $ — $ (.4 ) $ (.7 ) Net Periodic Postretirement Cost – Continuing Operations $ 2.9 $ 4.5 $ 5.1
Schedule of Changes in Projected Benefit Obligations	2017 2016 Obligation at beginning of year $ 86.3 $ 86.9 Service cost 1.1 2.2 Interest cost 1.6 2.0 Actuarial loss (gain) (7.2 ) 7.5 Curtailment gain (3.5 ) — Benefits paid (11.3 ) (12.3 ) Obligation at End of Year $ 67.0 $ 86.3
Schedule of Amounts Recognized in Balance Sheet	Amounts Recognized Accrued liabilities $ 10.0 $ 11.4 Noncurrent liabilities 57.0 74.9
Schedule of Amounts Recognized in Other Comprehensive Income (Loss)	The changes in benefit obligation that have been recognized in other comprehensive income on a pretax basis during 2017 and 2016 for our other postretirement benefit plans consist of the following: 2017 2016 Net actuarial loss (gain) arising during the period $ (10.7 ) $ 7.5 Amortization of net actuarial loss (.2 ) (.7 ) Total $ (10.9 ) $ 6.8
Schedule of Expected Benefit Payments	Projected benefit payments are as follows: 2018 $ 10.1 2019 9.5 2020 9.0 2021 8.4 2022 7.7 2023-2027 24.2

Commitments and Contingencies (

Commitments and Contingencies (Tables)	12 Months Ended
	Sep. 30, 2017
Commitments and Contingencies Disclosure [Abstract]
Schedule of Change in Asset Retirement Obligation	Changes to the carrying amount of our asset retirement obligations are as follows: Balance at 30 September 2015 $ 109.4 Additional accruals 10.4 Liabilities settled (4.4 ) Accretion expense 5.4 Currency translation adjustment (.9 ) Balance at 30 September 2016 $ 119.9 Additional accruals 22.7 Liabilities settled (4.1 ) Accretion expense 5.8 Currency translation adjustment .4 Balance at 30 September 2017 $ 144.7
Schedule of Unconditional Purchase Obligations Disclosure	We are obligated to make future payments under unconditional purchase obligations as summarized below: 2018 $ 822 2019 234 2020 275 2021 309 2022 285 Thereafter 4,608 Total $ 6,533

Capital Stock (Tables)

Capital Stock (Tables)	12 Months Ended
	Sep. 30, 2017
Equity [Abstract]
Schedule of Common Stock Outstanding	The following table reflects the changes in common shares: Year ended 30 September 2017 2016 2015 Number of Common Shares Outstanding Balance, beginning of year 217,350,825 215,359,113 213,538,144 Issuance of treasury shares for stock option and award plans 995,249 1,991,712 1,820,969 Balance, end of year 218,346,074 217,350,825 215,359,113

Share-Based Compensation (Table

Share-Based Compensation (Tables)	12 Months Ended
	Sep. 30, 2017
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Schedule of Recognized Share-Based Compensation Cost	Share-based compensation cost recognized in the consolidated income statements is summarized below: 2017 2016 2015 Before-Tax Share-Based Compensation Cost – Total $ 40.7 $ 37.6 $ 45.7 Before-Tax Share-Based Compensation Cost – Discontinued Operations .8 6.6 6.2 Before-Tax Share-Based Compensation Cost – Continuing Operations $ 39.9 $ 31.0 $ 39.5 Income tax benefit – Continuing Operations (14.0 ) (10.8 ) (13.8 ) After-Tax Share-Based Compensation Cost – Continuing Operations $ 25.9 $ 20.2 $ 25.7
Schedule of Before-Tax Share-Based Compensation Costs by Type of Program	On a total company basis, before-tax share-based compensation cost by type of program was as follows: 2017 2016 2015 Deferred stock units $ 34.5 $ 29.9 $ 28.8 Stock options 1.4 4.2 12.6 Restricted stock 4.8 3.5 4.3 Before-Tax Share-Based Compensation Cost – Total $ 40.7 $ 37.6 $ 45.7
Schedule of Assumptions for Fair Value of Market-Based Deferred Stock Units	The calculation of the fair value of market-based deferred stock units used the following assumptions: 2017 2016 Expected volatility 20.6 % 20.5 % Risk-free interest rate 1.4 % 1.2 % Expected dividend yield 2.5 % 2.2 %
Schedule of Deferred Stock Units and Restricted Stock Activity	Deferred Stock Units Shares (000) Weighted Average Grant-Date Fair Value Outstanding at 30 September 2016 1,001 $ 119.44 Equitable adjustment upon separation (A) 65 — Surrender upon separation (B) (89 ) 132.88 Granted 283 148.89 Paid out (235 ) 83.65 Forfeited/adjustments (50 ) 121.99 Outstanding at 30 September 2017 975 $ 127.29 (A) Applicable deferred stock units have been adjusted by the conversion ratio of 1.071 to preserve the intrinsic value immediately before and after the spin-off of Versum. (B) In connection with the spin-off of Versum, EMD employees surrendered their outstanding Air Products equity awards, which were converted into Versum equity awards of equivalent fair value. A summary of restricted stock activity is presented below: Restricted Stock Shares (000) Weighted Average Grant-Date Fair Value Outstanding at 30 September 2016 85 $ 128.16 Vested (29 ) 113.50 Outstanding at 30 September 2017 56 $ 135.74
Schedule of Assumptions for Fair Value of Stock Options	Fair values of stock options were estimated using a Black Scholes model that used the assumptions noted in the table below. Expected volatility and expected dividend yield are based on actual historical experience of our stock and dividends over the historical period equal to the expected life. The expected life represents the period of time that options granted are expected to be outstanding based on an analysis of Company-specific historical exercise data. Ranges are used when certain groups of employees exhibit different behavior, such as timing of exercise. The risk-free rate is based on the U.S. Treasury Strips with terms equal to the expected time of exercise as of the grant date. 2015 Expected volatility 30.3 % Expected dividend yield 2.6 % Expected life (in years) 7.5 Risk-free interest rate 2.2 %
Schedule of Stock Option Activity	A summary of stock option activity is presented below: Stock Options Shares (000) Weighted Average Exercise Price Outstanding at 30 September 2016 3,916 $ 90.28 Equitable adjustment upon separation (A) 277 — Surrender upon separation (B) (102 ) 97.63 Exercised (886 ) 80.76 Forfeited (3 ) 105.28 Outstanding at 30 September 2017 3,202 $ 84.85 Exercisable at 30 September 2017 3,149 $ 84.00 Stock Options Weighted Average Remaining Contractual Term (in years) Aggregate Intrinsic Value Outstanding at 30 September 2017 4.3 $ 213 Exercisable at 30 September 2017 4.3 $ 212 (A) Applicable deferred stock units have been adjusted by the conversion ratio of 1.071 to preserve the intrinsic value immediately before and after the spin-off of Versum. (B) In connection with the spin-off of Versum, EMD employees surrendered their outstanding Air Products equity awards, which were converted into Versum equity awards of equivalent fair value.

Accumulated Other Comprehensi52

Accumulated Other Comprehensive Loss (Tables)	12 Months Ended
	Sep. 30, 2017
Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract]
Schedule of Accumulated Other Comprehensive Income (Loss)	The table below summarizes changes in AOCL, net of tax, attributable to Air Products: Derivatives qualifying as hedges Foreign currency translation adjustments Pension and postretirement benefits Total Balance at 30 September 2014 $ (28.5 ) $ (268.7 ) $ (944.7 ) $ (1,241.9 ) Other comprehensive loss before reclassifications (35.0 ) (699.3 ) (278.5 ) (1,012.8 ) Amounts reclassified from AOCL 20.8 — 97.0 117.8 Net current period other comprehensive loss $ (14.2 ) $ (699.3 ) $ (181.5 ) $ (895.0 ) Amount attributable to noncontrolling interest .2 (11.5 ) .3 (11.0 ) Balance at 30 September 2015 $ (42.9 ) $ (956.5 ) $ (1,126.5 ) $ (2,125.9 ) Other comprehensive income (loss) before reclassifications 13.7 9.9 (335.1 ) (311.5 ) Amounts reclassified from AOCL (36.0 ) 2.7 87.2 53.9 Net current period other comprehensive income (loss) $ (22.3 ) $ 12.6 $ (247.9 ) $ (257.6 ) Amount attributable to noncontrolling interest (.2 ) 5.4 (.4 ) 4.8 Balance at 30 September 2016 $ (65.0 ) $ (949.3 ) $ (1,374.0 ) $ (2,388.3 ) Other comprehensive income (loss) before reclassifications (12.6 ) 101.9 251.6 340.9 Amounts reclassified from AOCL 24.2 57.3 110.7 192.2 Net current period other comprehensive income $ 11.6 $ 159.2 $ 362.3 $ 533.1 Spin-off of Versum .2 6.0 5.3 11.5 Amount attributable to noncontrolling interest (.1 ) 3.0 .8 3.7 Balance at 30 September 2017 $ (53.1 ) $ (787.1 ) $ (1,007.2 ) $ (1,847.4 )
Schedule of Reclassifications out of Accumulated Other Comprehensive Loss	The table below summarizes the reclassifications out of accumulated other comprehensive loss and the affected line item on the consolidated income statements: 2017 2016 2015 (Gain) Loss on Cash Flow Hedges, net of tax Sales/Cost of sales $ 18.3 $ .2 $ .6 Other income (expense), net 5.1 (46.2 ) 16.9 Interest expense .8 10.0 3.3 Total (Gain) Loss on Cash Flow Hedges, net of tax $ 24.2 $ (36.0 ) $ 20.8 Currency Translation Adjustment Business restructuring and cost reduction actions (A) $ 8.2 $ — $ — Income from discontinued operations, net of tax (B) 49.1 2.7 — Total Currency Translation Adjustment $ 57.3 $ 2.7 $ — Pension and Postretirement Benefits, net of tax (C) $ 110.7 $ 87.2 $ 97.0 (A) The fiscal year 2017 impact relates to the planned sale of a non-industrial gas hardgoods business in the Industrial Gases – Americas segment recorded in the third quarter. (B) The fiscal year 2017 impact relates to the sale of PMD during the second quarter. The fiscal year 2016 impact primarily relates to the sale of an equity affiliate in the first quarter. (C) The components include items such as prior service cost amortization, actuarial loss amortization, and settlements and are reflected in net periodic benefit cost. Refer to Note 16 , Retirement Benefits .

Earnings per Share (Tables)

Earnings per Share (Tables)	12 Months Ended
	Sep. 30, 2017
Earnings Per Share [Abstract]
Schedule of Computation of Basic and Diluted Earnings Per Share	The following table sets forth the computation of basic and diluted earnings per share (EPS): 30 September 2017 2016 2015 Numerator Income from continuing operations $ 1,134.4 $ 1,099.5 $ 933.3 Income (Loss) from discontinued operations 1,866.0 (468.4 ) 344.6 Net Income Attributable to Air Products $ 3,000.4 $ 631.1 $ 1,277.9 Denominator (in millions) Weighted average common shares — Basic 218.0 216.4 214.9 Effect of dilutive securities Employee stock option and other award plans 1.8 1.9 2.4 Weighted average common shares — Diluted 219.8 218.3 217.3 Basic EPS Attributable to Air Products Income from continuing operations $ 5.20 $ 5.08 $ 4.34 Income (Loss) from discontinued operations 8.56 (2.16 ) 1.61 Net Income Attributable to Air Products $ 13.76 $ 2.92 $ 5.95 Diluted EPS Attributable to Air Products Income from continuing operations $ 5.16 $ 5.04 $ 4.29 Income (Loss) from discontinued operations 8.49 (2.15 ) 1.59 Net Income Attributable to Air Products $ 13.65 $ 2.89 $ 5.88

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Sep. 30, 2017
Income Tax Disclosure [Abstract]
Schedule of Income of U.S. and Foreign Operations Before Taxes	The following table summarizes the income of U.S. and foreign operations before taxes: 2017 2016 2015 Income from Continuing Operations before Taxes United States $ 669.8 $ 631.7 $ 507.5 Foreign 666.2 775.9 606.3 Income from equity affiliates 80.1 147.0 152.3 Total $ 1,416.1 $ 1,554.6 $ 1,266.1
Schedule of Components of Income Tax Expense (Benefit)	The following table shows the components of the provision for income taxes: 2017 2016 2015 Current Tax Provision Federal $ 62.8 $ 171.0 $ 117.0 State 7.0 21.2 8.1 Foreign 229.1 178.6 165.7 298.9 370.8 290.8 Deferred Tax Provision Federal 1.4 45.0 1.5 State 6.0 2.8 17.8 Foreign (45.4 ) 14.0 (9.9 ) (38.0 ) 61.8 9.4 Income Tax Provision $ 260.9 $ 432.6 $ 300.2
Schedule of Effective Income Tax Rate Reconciliation	A reconciliation of the differences between the United States federal statutory tax rate and the effective tax rate is as follows: (Percent of income before taxes) 2017 2016 2015 U.S. federal statutory tax rate 35.0 % 35.0 % 35.0 % State taxes, net of federal benefit 1.0 1.2 1.1 Income from equity affiliates (2.0 ) (3.3 ) (4.0 ) Foreign tax differentials (7.9 ) (6.6 ) (5.9 ) U.S. taxes on foreign earnings (2.2 ) (3.1 ) (2.1 ) Domestic production activities (.8 ) (.8 ) (1.0 ) Non-deductible goodwill impairment charge 3.6 — — Non-U.S. subsidiary tax election (7.7 ) — — Business separation costs .2 4.2 .2 Share-based compensation (1.2 ) — — Other .4 1.2 .4 Effective Tax Rate 18.4 % 27.8 % 23.7 %
Schedule of Components of Deferred Tax Assets and Liabilities	The significant components of deferred tax assets and liabilities are as follows: 30 September 2017 2016 Gross Deferred Tax Assets Retirement benefits and compensation accruals $ 370.1 $ 527.6 Tax loss carryforwards 64.5 101.1 Tax credits and other tax carryforwards 76.1 56.0 Reserves and accruals 88.2 74.9 Partnership and other investments — 5.8 Currency losses 20.7 — Other 37.2 19.3 Valuation allowance (107.7 ) (165.1 ) Deferred Tax Assets 549.1 619.6 Gross Deferred Tax Liabilities Plant and equipment 1,035.6 985.1 Currency gains — 46.8 Unremitted earnings of foreign entities 20.9 5.4 Partnership and other investments 5.4 — Intangible assets 81.9 91.0 Other 9.2 16.7 Deferred Tax Liabilities 1,153.0 1,145.0 Net Deferred Income Tax Liability $ 603.9 $ 525.4
Schedule of Deferred Tax Assets and Liabilities Included in Consolidated Financial Statements	Deferred tax assets and liabilities are included within the consolidated financial statements as follows: 2017 2016 Deferred Tax Assets Other noncurrent assets $ 174.5 $ 185.0 Deferred Tax Liabilities Deferred income taxes 778.4 710.4 Net Deferred Income Tax Liability $ 603.9 $ 525.4
Schedule of Reconciliation of Unrecognized Tax Benefits	A reconciliation of the beginning and ending amount of the unrecognized tax benefits is as follows: Unrecognized Tax Benefits 2017 2016 2015 Balance at beginning of year $ 90.2 $ 83.8 $ 93.1 Additions for tax positions of the current year 47.5 12.5 4.7 Additions for tax positions of prior years 16.1 2.9 3.0 Reductions for tax positions of prior years (4.0 ) — (2.2 ) Settlements (2.0 ) (5.6 ) (.6 ) Statute of limitations expiration (3.2 ) (2.9 ) (8.3 ) Foreign currency translation 1.8 (.5 ) (5.9 ) Balance at End of Year $ 146.4 $ 90.2 $ 83.8
Schedule of Income Tax Examinations	We generally remain subject to examination in the following major tax jurisdictions for the years indicated below: Major Tax Jurisdiction Open Tax Years North America United States 2011-2017 Canada 2013-2017 Europe France 2014-2017 Germany 2012-2017 Netherlands 2012-2017 Spain 2011-2017 United Kingdom 2014-2017 Asia China 2012-2017 South Korea 2010-2017 Taiwan 2012-2017 Latin America Chile 2013-2017

Supplemental Information (Table

Supplemental Information (Tables)	12 Months Ended
	Sep. 30, 2017
Supplemental Information [Abstract]
Schedule of Other Receivables and Current Assets	Other Receivables and Current Assets 30 September 2017 2016 Derivative instruments $ 93.9 $ 169.3 Other receivables 188.0 181.7 Current capital lease receivables 93.3 88.2 Prepaid inventory — 92.8 Other 28.1 6.2 Other receivables and current assets $ 403.3 $ 538.2
Schedule of Other Noncurrent Assets	Other Noncurrent Assets 30 September 2017 2016 Derivative instruments $ 133.9 $ 204.4 Other long-term receivables 82.1 16.9 Prepaid tax 5.1 37.0 Deferred tax assets 174.5 185.0 Pension benefits 18.4 — Deposits 34.8 36.5 Other 193.0 191.2 Other noncurrent assets $ 641.8 $ 671.0
Schedule of Payables and Accrued Liabilities	Payables and Accrued Liabilities 30 September 2017 2016 Trade creditors $ 659.5 $ 578.8 Customer advances 438.9 371.2 Accrued payroll and employee benefits 187.1 217.1 Pension and postretirement benefits 22.6 35.5 Dividends payable 207.5 186.9 Outstanding payments in excess of certain cash balances 4.5 11.9 Accrued interest expense 42.2 47.9 Derivative instruments 95.9 73.5 Severance and other costs associated with business restructuring and cost reduction actions 41.5 15.7 Other 114.6 113.7 Payables and accrued liabilities $ 1,814.3 $ 1,652.2
Schedule of Other Noncurrent Liabilities	Other Noncurrent Liabilities 30 September 2017 2016 Pension benefits $ 703.8 $ 1,155.1 Postretirement benefits 57.0 74.9 Other employee benefits 99.3 104.1 Contingencies related to uncertain tax positions 130.6 78.0 Advance payments 39.0 43.8 Environmental liabilities 72.3 70.3 Derivative instruments 36.0 21.8 Asset retirement obligations 144.0 116.1 Obligation for future contribution to an equity affiliate 94.4 94.4 Obligations associated with EfW 65.3 — Other 170.2 58.0 Other noncurrent liabilities $ 1,611.9 $ 1,816.5
Schedule of Other Income (Expense), Net	Other Income (Expense), Net 30 September 2017 2016 2015 Technology and royalty income $ 20.8 $ 19.0 $ 22.8 Interest income (A) 1.5 6.1 4.2 Foreign exchange 4.3 (7.2 ) (22.6 ) Sale of assets and investments 24.3 8.8 36.3 Contract settlements 14.3 12.6 — Transition service agreements reimbursement (B) 38.4 — — Other 17.4 10.1 4.8 Other income (expense), net $ 121.0 $ 49.4 $ 45.5 (A) Beginning in the second quarter of fiscal year 2017, interest income associated with our short-term investments is reflected on the consolidated income statements in "Other non-operating income (expense), net." (B) Reflects reimbursement for costs in support of transition services agreements with Versum for EMD and with Evonik for PMD. Refer to Note 4 , Materials Technologies Separation , for additional information.
Schedule of Changes in Redeemable Noncontrolling Interest	The following is a summary of the changes in redeemable noncontrolling interest for the year ended 30 September 2015: Balance at 30 September 2014 $ 287.2 Net income 11.5 Dividends (2.0 ) Purchase of noncontrolling interest (277.9 ) Currency translation adjustment (18.8 ) Balance at 30 September 2015 $ —

Summary by Quarter (Unaudited)

Summary by Quarter (Unaudited) (Tables)	12 Months Ended
	Sep. 30, 2017
Quarterly Financial Information Disclosure [Abstract]
Schedule of Quarterly Financial Information	These tables summarize the unaudited results of operations for each quarter of 2017 and 2016 : 2017 Q1 Q2 Q3 Q4 Total Sales $ 1,882.5 $ 1,980.1 $ 2,121.9 $ 2,203.1 $ 8,187.6 Gross profit (A) 564.4 576.3 635.7 657.8 2,434.2 Business separation costs (B) 30.2 — — — 30.2 Business restructuring and cost reduction actions (C) 50.0 10.3 42.7 48.4 151.4 Pension settlement loss (D) — 4.1 5.5 .9 10.5 Goodwill and intangible asset impairment charge (E) — — 162.1 — 162.1 Gain on land sale (F) — — — 12.2 12.2 Operating income (A) 328.1 391.2 252.6 455.7 1,427.6 Equity affiliates' income (loss) 38.0 34.2 (36.9 ) (G) 44.8 80.1 (G) Income tax provision (benefit) 78.4 94.5 89.3 (1.3 ) (H) 260.9 (H) Net income 306.4 2,135.7 104.1 475.0 3,021.2 Net income attributable to Air Products Income from continuing operations 251.6 304.4 104.2 474.2 1,134.4 Income (Loss) from discontinued operations 48.2 1,825.6 (I) (2.3 ) (5.5 ) 1,866.0 (I) Net income attributable to Air Products 299.8 2,130.0 101.9 468.7 3,000.4 Basic Earnings Per Common Share Attributable to Air Products Income from continuing operations 1.16 1.40 .48 2.17 5.20 Income (Loss) from discontinued operations .22 8.38 (.01 ) (.02 ) 8.56 Net income attributable to Air Products 1.38 9.78 .47 2.15 13.76 Diluted Earnings Per Common Share Attributable to Air Products Income from continuing operations 1.15 1.39 .47 2.15 5.16 Income (Loss) from discontinued operations .22 8.31 (.01 ) (.02 ) 8.49 Net income attributable to Air Products 1.37 9.70 .46 2.13 13.65 Dividends declared per common share .86 .95 .95 .95 3.71 Market price per common share – High 150.45 149.46 147.66 152.26 Market price per common share – Low 129.00 133.63 134.09 141.88 2016 Q1 Q2 Q3 Q4 Total Sales $ 1,866.3 $ 1,777.4 $ 1,914.5 $ 1,945.5 $ 7,503.7 Gross profit (A) 570.4 564.4 594.3 598.0 2,327.1 Business separation costs (B) 12.0 7.4 9.5 21.7 50.6 Business restructuring and cost reduction actions (C) — 10.7 13.2 10.6 34.5 Pension settlement loss (D) — 2.0 1.0 2.1 5.1 Operating income (A) 372.5 371.6 394.6 391.0 1,529.7 Equity affiliates' income 33.3 32.3 42.1 39.3 147.0 Loss on extinguishment of debt (J) — — — 6.9 6.9 Income tax provision 96.4 93.5 (K) 145.9 (K) 96.8 (K) 432.6 (K) Net income (loss) 372.0 (465.5 ) 354.1 400.9 661.5 Net income attributable to Air Products Income from continuing operations 280.9 278.9 250.3 289.4 1,099.5 Income (Loss) from discontinued operations 82.7 (752.2 ) 96.5 104.6 (468.4 ) Net income (loss) attributable to Air Products 363.6 (473.3 ) 346.8 394.0 631.1 Basic Earnings Per Common Share Attributable to Air Products Income from continuing operations 1.30 1.29 1.16 1.33 5.08 Income (Loss) from discontinued operations .38 (3.48 ) .44 .48 (2.16 ) Net income (loss) attributable to Air Products 1.68 (2.19 ) 1.60 1.81 2.92 Diluted Earnings Per Common Share Attributable to Air Products Income from continuing operations 1.29 1.28 1.15 1.32 5.04 Income (Loss) from discontinued operations .38 (3.45 ) .44 .48 (2.15 ) Net income (loss) attributable to Air Products 1.67 (2.17 ) 1.59 1.80 2.89 Dividends declared per common share .81 .86 .86 .86 3.39 Market price per common share – High 133.78 136.88 141.53 146.82 Market price per common share – Low 117.80 106.63 124.78 127.72 (A) Changes in estimates on projects accounted for under the percentage of completion method favorably impacted income by approximately $27 in fiscal year 2017 and $20 in fiscal year 2016 , primarily during the fourth quarter. For additional information, see Note 1 , Major Accounting Policies (Revenue Recognition). (B) For additional information, see Note 4 , Materials Technologies Separation . (C) For additional information, see Note 5 , Business Restructuring and Cost Reduction Actions . (D) For additional information, see Note 16 , Retirement Benefits . (E) For additional information, see Note 10 , Goodwill , and Note 11 , Intangible Assets . (F) The gain is reflected on the consolidated income statements in "Other income (expense), net." For additional information, see Note 23 , Supplemental Information . (G) Includes the impact of an other-than-temporary impairment of an investment in an equity affiliate. For additional information, see Note 8 , Summarized Financial Information of Equity Affiliates . (H) Includes the impact of a tax election benefit related to a non-U.S. subsidiary. For additional information, see Note 22 , Income Taxes . (I) Includes the after-tax gain on the sale of PMD. For additional information, see Note 3 , Discontinued Operations . (J) For additional information, see Note 15 , Debt . (K) Includes income tax expense for tax costs associated with business separation. For additional information, see Note 4 , Materials Technologies Separation .

Business Segment and Geograph57

Business Segment and Geographic Information (Tables)	12 Months Ended
	Sep. 30, 2017
Segment Reporting [Abstract]
Schedule of Segment Reporting Information by Segment	Business Segment Industrial Gases– Americas Industrial Gases– EMEA Industrial Gases– Asia Industrial Gases– Global Corporate and other Segment Total 2017 Sales to external customers $ 3,637.0 $ 1,780.4 $ 1,964.7 $ 722.9 $ 82.6 $ 8,187.6 Operating income (loss) 950.6 387.1 531.2 71.3 (170.6 ) 1,769.6 Depreciation and amortization 464.4 177.1 203.2 8.9 12.2 865.8 Equity affiliates' income 58.1 47.1 53.5 .9 — 159.6 Expenditures for long-lived assets 427.2 143.2 337.8 25.6 105.9 1,039.7 Investments in net assets of and advances to equity affiliates 287.5 508.6 471.8 19.0 — 1,286.9 Total assets 5,840.8 3,276.1 4,412.1 279.6 4,648.4 18,457.0 2016 Sales to external customers $ 3,344.1 $ 1,704.4 $ 1,720.4 $ 498.8 $ 236.0 $ 7,503.7 Operating income (loss) 893.2 384.6 451.0 (21.3 ) (87.6 ) 1,619.9 Depreciation and amortization 443.6 185.7 197.9 7.9 19.5 854.6 Equity affiliates' income 52.7 36.5 57.8 — — 147.0 Expenditures for long-lived assets 406.6 159.5 313.3 6.0 22.3 907.7 Investments in net assets of and advances to equity affiliates 250.6 580.5 442.5 10.0 — 1,283.6 Total assets 5,896.7 3,178.6 4,232.7 367.6 2,384.5 16,060.1 2015 Sales to external customers $ 3,694.5 $ 1,866.4 $ 1,661.3 $ 286.7 $ 315.4 $ 7,824.3 Operating income (loss) 806.1 331.3 389.3 (51.6 ) (86.5 ) 1,388.6 Depreciation and amortization 417.5 194.3 209.9 16.5 20.3 858.5 Equity affiliates' income (loss) 64.6 42.4 46.1 (.8 ) — 152.3 Expenditures for long-lived assets 414.5 215.6 402.5 94.8 35.0 1,162.4 Investments in net assets of and advances to equity affiliates 249.7 564.1 421.7 14.3 — 1,249.8 Total assets 5,782.5 3,324.1 4,159.1 370.5 1,123.8 14,760.0
Reconciliation of Segments to Consolidated Operating Income	Below is a reconciliation of segment total operating income to consolidated operating income: Operating Income 2017 2016 2015 Segment total $ 1,769.6 $ 1,619.9 $ 1,388.6 Business separation costs (30.2 ) (50.6 ) (7.5 ) Business restructuring and cost reduction actions (151.4 ) (34.5 ) (180.1 ) Pension settlement loss (10.5 ) (5.1 ) (19.3 ) Goodwill and intangible asset impairment charge (162.1 ) — — Gain on previously held equity interest — — 17.9 Gain on land sales (A) 12.2 — 33.6 Consolidated Total $ 1,427.6 $ 1,529.7 $ 1,233.2 (A) Reflected on the consolidated income statements in “Other income (expense), net.”
Reconciliation of Segments to Consolidated Equity Affiliates' Income	Below is a reconciliation of segment total equity affiliates' income to consolidated equity affiliates' income : Equity Affiliates' Income 2017 2016 2015 Segment total $ 159.6 $ 147.0 $ 152.3 Equity method investment impairment charge (79.5 ) — — Consolidated Total $ 80.1 $ 147.0 $ 152.3
Reconciliation of Segments to Consolidated Total Assets	Below is a reconciliation of segment total assets to consolidated total assets: Total Assets 2017 2016 2015 Segment total $ 18,457.0 $ 16,060.1 $ 14,760.0 Discontinued operations 10.2 1,968.5 2,556.6 Consolidated Total $ 18,467.2 $ 18,028.6 $ 17,316.6
Schedule of Revenue and Long-Lived Assets by Geographical Areas	Geographic Information Sales to External Customers 2017 2016 2015 United States $ 2,886.8 $ 2,911.7 $ 3,369.8 Europe, including Middle East 2,478.5 2,186.5 1,989.2 Asia, excluding China and India 849.6 721.4 736.8 China 1,143.4 1,020.4 957.8 Other (A) 829.3 663.7 770.7 Total $ 8,187.6 $ 7,503.7 $ 7,824.3 Long-Lived Assets (B) 2017 2016 2015 United States $ 3,407.4 $ 3,411.4 $ 3,502.9 Europe, including Middle East 1,279.0 1,292.5 1,379.8 Asia, excluding China and India 778.5 707.0 627.1 China 1,737.9 1,675.8 1,682.8 Other (A) 1,237.4 1,173.0 1,044.7 Total $ 8,440.2 $ 8,259.7 $ 8,237.3 (A) Includes Canada, Latin America, and India. (B) Long-lived assets include plant and equipment, net.

Major Accounting Policies (Narr

Major Accounting Policies (Narrative) (Details) - USD ($)

3 Months Ended

12 Months Ended

Sep. 30, 2017

Jun. 30, 2017

[1]

Mar. 31, 2017

[1]

Dec. 31, 2016

[1]

Sep. 30, 2016

Jun. 30, 2016

[1]

Mar. 31, 2016

[1]

Dec. 31, 2015

[1]

Sep. 30, 2017

Sep. 30, 2016

Sep. 30, 2015

Accounting Policies [Abstract]

Environmental expenditures

$ 11,400,000

$ 12,200,000

$ 11,800,000

Allowance for doubtful accounts

$ 93,500,000

$ 55,300,000

93,500,000

55,300,000

Provision for doubtful accounts

45,800,000

21,800,000

25,900,000

Capitalized interest

19,000,000

32,700,000

19,000,000

32,700,000

49,100,000

Asset retirement obligations

144,700,000

119,900,000

$ 144,700,000

119,900,000

109,400,000

Period for reallocation of purchase price

1 year

Finite-Lived Intangible Assets [Line Items]

Finite-lived intangible assets, residual value

0

$ 0

Change in Accounting Estimate [Line Items]

Operating income

$ 455,700,000

[1]

$ 252,600,000

$ 391,200,000

$ 328,100,000

$ 391,000,000

[1]

$ 394,600,000

$ 371,600,000

$ 372,500,000

$ 1,427,600,000

[1]

1,529,700,000

[1]

$ 1,233,200,000

Software and Software Development Costs | Minimum

Property, Plant and Equipment [Line Items]

Property and equipment, useful life

3 years

Software and Software Development Costs | Maximum

Property, Plant and Equipment [Line Items]

Property and equipment, useful life

10 years

Customer Relationships | Minimum

Finite-Lived Intangible Assets [Line Items]

Finite-lived intangible assets, useful life

5 years

Customer Relationships | Maximum

Finite-Lived Intangible Assets [Line Items]

Finite-lived intangible assets, useful life

25 years

Patents and Technology | Minimum

Finite-Lived Intangible Assets [Line Items]

Finite-lived intangible assets, useful life

5 years

Patents and Technology | Maximum

Finite-Lived Intangible Assets [Line Items]

Finite-lived intangible assets, useful life

15 years

Land Use Rights

Finite-Lived Intangible Assets [Line Items]

Finite-lived intangible assets, useful life

50 years

Contracts accounted for under percentage of completion

Change in Accounting Estimate [Line Items]

Operating income

$ 27,000,000

$ 20,000,000

[1]

Changes in estimates on projects accounted for under the percentage of completion method favorably impacted income by approximately $27 in fiscal year 2017 and $20 in fiscal year 2016, primarily during the fourth quarter. For additional information, see Note 1, Major Accounting Policies (Revenue Recognition).

New Accounting Guidance (Narrat

New Accounting Guidance (Narrative) (Details) - USD ($) $ in Millions	12 Months Ended
	Sep. 30, 2017	Oct. 01, 2016	Sep. 30, 2016
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Excess tax benefits recognized under new accounting standard	$ 17.6
Accounting Standards Update 2016-09 | Early Adoption, Effect | Retained Earnings
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cumulative-effect adjustment related to adoption of new accounting standard		$ 8.8
Accounting Standards Update 2015-03 | Other Noncurrent Assets
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Reclassification of debt issuance cost with (decrease) to assets and decrease to liabilities			$ (17)
Accounting Standards Update 2015-03 | Other Noncurrent Assets | Discontinued Operations
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Reclassification of debt issuance cost with (decrease) to assets and decrease to liabilities			(9.6)
Accounting Standards Update 2015-03 | Long-term Debt
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Reclassification of debt issuance cost with (decrease) to assets and decrease to liabilities			17
Accounting Standards Update 2015-03 | Other Noncurrent Liabilities | Discontinued Operations
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Reclassification of debt issuance cost with (decrease) to assets and decrease to liabilities			$ 9.6

Discontinued Operations (Narrat

Discontinued Operations (Narrative) (Details) $ / shares in Units, $ in Millions	Jan. 03, 2017USD ($)$ / shares	Oct. 01, 2016	Dec. 31, 2016USD ($)	Mar. 31, 2016USD ($)	Sep. 30, 2017USD ($)		Sep. 30, 2016USD ($)	Sep. 30, 2015USD ($)	Sep. 30, 2014USD ($)
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Deferred tax assets, valuation allowance					$ 107.7		$ 165.1
Unrecognized tax benefits					146.4		90.2	$ 83.8	$ 93.1
Electronic Materials Division (EMD) | Discontinued Operations, Spinoff
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Distribution ratio of common stock in spin-off		0.5
Loss on disposal, after tax							0
Performance Materials Division (PMD) | Discontinued Operations, Held-for-sale or Disposed of by Sale
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Proceeds from sale	$ 3,800
Gain on sale, before tax	2,870
Gain on sale, after tax	$ 1,828				1,827.6	[1]
Gain on sale, after tax, per share | $ / shares	$ 8.32
Loss on disposal, after tax							0
Energy-from-Waste (EfW) | Discontinued Operations, Held-for-sale or Disposed of by Sale
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Gain on sale, after tax					(47.1)
Loss on disposal, before tax			$ 59.3	$ 945.7	59.3		945.7
Loss on disposal, after tax			47.1	846.6			846.6
Deferred tax assets, valuation allowance				58
Unrecognized tax benefits				$ 7.9
Energy-from-Waste (EfW) | Discontinued Operations, Held-for-sale or Disposed of by Sale | Asset Actions
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Loss on disposal, before tax			6.3		6.3		913.5
Energy-from-Waste (EfW) | Discontinued Operations, Held-for-sale or Disposed of by Sale | Contract Actions/ Other
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Loss on disposal, before tax			$ 53		$ 53		$ 32.2
[1]	After-tax gain on sale of $1,827.6 includes expense for income tax reserves for uncertain tax positions of $28.0 gross ($21.0 net) in various jurisdictions.

Discontinued Operations (Carryi

Discontinued Operations (Carrying Amount of Accrual) (Details) - Energy-from-Waste (EfW) - Discontinued Operations, Held-for-sale or Disposed of by Sale - USD ($) $ in Millions	3 Months Ended		12 Months Ended
	Dec. 31, 2016	Mar. 31, 2016	Sep. 30, 2017	Sep. 30, 2016
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Loss on disposal of business	$ 59.3	$ 945.7	$ 59.3	$ 945.7
Noncash expenses			(6.3)	(913.5)
Cash expenditures			(1.4)	(18.6)
Currency translation adjustment			7.3	(1.4)
Amount reflected in other noncurrent liabilities			(65.3)
Accrual for actions to dispose of business			5.8	12.2
Asset Actions
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Loss on disposal of business	6.3		6.3	913.5
Noncash expenses			(6.3)	(913.5)
Cash expenditures			0	0
Currency translation adjustment			0	0
Amount reflected in other noncurrent liabilities			0
Accrual for actions to dispose of business			0	0
Contract Actions/ Other
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Loss on disposal of business	$ 53		53	32.2
Noncash expenses			0	0
Cash expenditures			(1.4)	(18.6)
Currency translation adjustment			7.3	(1.4)
Amount reflected in other noncurrent liabilities			(65.3)
Accrual for actions to dispose of business			$ 5.8	$ 12.2

Discontinued Operations (Schedu

Discontinued Operations (Schedule of Operating Results) (Details) - USD ($) $ in Millions	Jan. 03, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	[1]	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2017		Sep. 30, 2016		Sep. 30, 2015
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Income (loss) from Discontinued Operations, net of tax											$ 1,866		$ (460.5)		$ 351.7
Net Income Attributable to Noncontrolling Interests of Discontinued Operations											0		7.9		7.1
Net Income (Loss) From Discontinued Operations		$ (5.5)	$ (2.3)	$ 1,825.6		$ 48.2	$ 104.6	$ 96.5	$ (752.2)	$ 82.7	1,866	[1]	(468.4)		344.6
Discontinued Operations
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Sales											254.8		2,020.7		2,070.6
Cost of sales											196.1		1,250.7		1,345.9
Selling and administrative											23.2		167.1		168.7
Research and development											5.1		61.3		62.4
Other income (expense), net											(1.7)		(6.3)		(27.7)	[2]
Operating Income (Loss)											28.7		535.3		465.9
Equity affiliates' income											0.3		1.6		2.2
Interest expense													0.3		0.7
Income (Loss) Before Taxes											29		536.6	[3]	467.4	[4]
Income tax provision (benefit)											(56.5)	[5]	150.5		115.7
Income (Loss) From Operations of Discontinued Operations, net of tax											85.5		386.1
Gain (Loss) on Disposal, net of tax											1,780.5
Loss on Disposal, net of tax													(846.6)
Income (loss) from Discontinued Operations, net of tax											1,866		(460.5)		351.7
Net Income Attributable to Noncontrolling Interests of Discontinued Operations													7.9		7.1
Net Income (Loss) From Discontinued Operations													(468.4)		344.6
Income before taxes from operations of discontinued operations attributable to Air Products													527.1		458.9
Electronic Materials Division (EMD) | Discontinued Operations, Spinoff
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Sales													961.6		984.1
Cost of sales													521.6		586.8
Selling and administrative													87.7		86.4
Research and development													40.8		37.5
Other income (expense), net													2.2		(18.5)	[2]
Operating Income (Loss)													313.7		254.9
Equity affiliates' income													0.2		1
Interest expense													0.3		0.1
Income (Loss) Before Taxes													313.6		255.8
Income tax provision (benefit)													73.4		49.7
Income (Loss) From Operations of Discontinued Operations, net of tax													240.2
Loss on Disposal, net of tax													0
Income (loss) from Discontinued Operations, net of tax													240.2		206.1
Net Income Attributable to Noncontrolling Interests of Discontinued Operations													7.9		7.1
Net Income (Loss) From Discontinued Operations													232.3		199
Performance Materials Division (PMD) | Discontinued Operations, Held-for-sale or Disposed of by Sale
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Sales											254.8		1,059.1		1,086.5
Cost of sales											182.3		704.5		754
Selling and administrative											22.5		76.6		79.9
Research and development											5.1		19.6		23.2
Other income (expense), net											0.3		4.2		(9.2)	[2]
Operating Income (Loss)											45.2		262.6		220.2
Equity affiliates' income											0.3		1.4		1.2
Interest expense													0		0.6
Income (Loss) Before Taxes											45.5		264		220.8
Income tax provision (benefit)											(50.8)	[5]	80.5		68.4
Income (Loss) From Operations of Discontinued Operations, net of tax											96.3		183.5
Gain (Loss) on Disposal, net of tax	$ 1,828										1,827.6	[6]
Loss on Disposal, net of tax													0
Income (loss) from Discontinued Operations, net of tax											1,923.9		183.5		152.4
Net Income Attributable to Noncontrolling Interests of Discontinued Operations													0		0
Net Income (Loss) From Discontinued Operations													183.5		152.4
Valuation allowance adjustment effect on income tax provision						69
Gross expense for income tax reserves included in provision for gain on disposal											28
Net expense for income tax reserves included in provision for gain on disposal											21
Energy-from-Waste (EfW) | Discontinued Operations, Held-for-sale or Disposed of by Sale
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Sales											0		0		0
Cost of sales											13.8		24.6		5.1
Selling and administrative											0.7		2.8		2.4
Research and development											0		0.9		1.7
Other income (expense), net											(2)		(12.7)		0	[2]
Operating Income (Loss)											(16.5)	[7]	(41)	[8]	(9.2)	[9]
Equity affiliates' income											0		0		0
Interest expense													0		0
Income (Loss) Before Taxes											(16.5)	[7]	(41)	[8]	(9.2)	[9]
Income tax provision (benefit)											(5.7)		(3.4)		(2.4)
Income (Loss) From Operations of Discontinued Operations, net of tax											(10.8)	[7]	(37.6)	[8]
Gain (Loss) on Disposal, net of tax											(47.1)
Loss on Disposal, net of tax						$ (47.1)			$ (846.6)				(846.6)
Income (loss) from Discontinued Operations, net of tax											$ (57.9)		(884.2)		(6.8)	[9]
Net Income Attributable to Noncontrolling Interests of Discontinued Operations													0		0
Net Income (Loss) From Discontinued Operations													$ (884.2)		$ (6.8)
[1]	Includes the after-tax gain on the sale of PMD. For additional information, see Note 3, Discontinued Operations.
[2]	Primarily includes business restructuring and cost reduction actions.
[3]	In fiscal year 2016, income before taxes from operations of discontinued operations attributable to Air Products was $527.1.
[4]	In fiscal year 2015, income before taxes from operations of discontinued operations attributable to Air Products was $458.9.
[5]	As a result of the expected gain on sale of PMD, we released valuation allowances related to capital loss and net operating loss carryforwards primarily during the first quarter of 2017 that favorably impacted our income tax provision within discontinued operations by approximately $69.
[6]	After-tax gain on sale of $1,827.6 includes expense for income tax reserves for uncertain tax positions of $28.0 gross ($21.0 net) in various jurisdictions.
[7]	The loss from operations of discontinued operations for EfW primarily relates to costs incurred for ongoing project exit activities, administrative costs, and land lease obligations.
[8]	The loss from operations of discontinued operations for EfW primarily relates to project suspension costs, land lease obligations, and administrative costs.
[9]	The loss from operations of discontinued operations for EfW primarily relates to land lease obligations and administrative costs.

Discontinued Operations (Sche63

Discontinued Operations (Schedule of Assets and Liabilities) (Details) - USD ($) $ in Millions	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2015
Current Assets
Cash and cash items	$ 0	$ 208.1	$ 23.3
Total Current Assets	10.2	926.2
Total Noncurrent Assets	0	1,042.3
Current Liabilities
Total Current Liabilities	15.7	211.8
Total Noncurrent Liabilities	0	1,095.5
Discontinued Operations
Current Assets
Cash and cash items		208.1
Trade receivables, net		293.7
Inventories		364.9
Plant and equipment, net	10.2	18.2
Other receivables and current assets		41.3
Total Current Assets	10.2	926.2
Plant and equipment, net		593
Goodwill, net		305
Intangible assets, net		100.1
Other noncurrent assets		44.2
Total Noncurrent Assets		1,042.3
Total Assets	10.2	1,968.5
Current Liabilities
Payables and accrued liabilities	15.7	177.3
Accrued income taxes		28.7
Current portion of long-term debt		5.8
Total Current Liabilities	15.7	211.8
Long-term debt		981.8
Deferred income taxes		56.7
Other noncurrent liabilities		57
Total Noncurrent Liabilities		1,095.5
Total Liabilities	15.7	1,307.3
Electronic Materials Division (EMD) | Discontinued Operations, Spinoff
Current Assets
Cash and cash items		170.6
Trade receivables, net		134.7
Inventories		138.1
Plant and equipment, net		0
Other receivables and current assets		34.5
Total Current Assets		477.9
Plant and equipment, net		296.5
Goodwill, net		180
Intangible assets, net		75.1
Other noncurrent assets		37.5
Total Noncurrent Assets		589.1
Total Assets		1,067
Current Liabilities
Payables and accrued liabilities		85.8
Accrued income taxes		22.7
Current portion of long-term debt		5.8
Total Current Liabilities		114.3
Long-term debt		981.8
Deferred income taxes		50.3
Other noncurrent liabilities		47.4
Total Noncurrent Liabilities		1,079.5
Total Liabilities		1,193.8
Performance Materials Division (PMD) | Discontinued Operations, Held-for-sale or Disposed of by Sale
Current Assets
Cash and cash items		37.5
Trade receivables, net		159
Inventories		226.8
Plant and equipment, net	0	0
Other receivables and current assets		5.6
Total Current Assets	0	428.9
Plant and equipment, net		296.5
Goodwill, net		125
Intangible assets, net		25
Other noncurrent assets		6.7
Total Noncurrent Assets		453.2
Total Assets	0	882.1
Current Liabilities
Payables and accrued liabilities	9.2	72.5
Accrued income taxes		6
Current portion of long-term debt		0
Total Current Liabilities	9.2	78.5
Long-term debt		0
Deferred income taxes		6.4
Other noncurrent liabilities		9.6
Total Noncurrent Liabilities		16
Total Liabilities	9.2	94.5
Energy-from-Waste (EfW) | Discontinued Operations, Held-for-sale or Disposed of by Sale
Current Assets
Cash and cash items		0
Trade receivables, net		0
Inventories		0
Plant and equipment, net	10.2	18.2
Other receivables and current assets		1.2
Total Current Assets	10.2	19.4
Plant and equipment, net		0
Goodwill, net		0
Intangible assets, net		0
Other noncurrent assets		0
Total Noncurrent Assets		0
Total Assets	10.2	19.4
Current Liabilities
Payables and accrued liabilities	6.5	19
Accrued income taxes		0
Current portion of long-term debt		0
Total Current Liabilities	6.5	19
Long-term debt		0
Deferred income taxes		0
Other noncurrent liabilities		0
Total Noncurrent Liabilities		0
Total Liabilities	$ 6.5	$ 19

Materials Technologies Separa64

Materials Technologies Separation (Narrative) (Details) - USD ($) $ in Millions

Jan. 03, 2017

Sep. 30, 2016

Sep. 30, 2017

[1]

Jun. 30, 2017

[1]

Mar. 31, 2017

[1]

Dec. 31, 2016

[1]

Sep. 30, 2016

Jun. 30, 2016

Mar. 31, 2016

Dec. 31, 2015

Sep. 30, 2017

Sep. 30, 2016

Sep. 30, 2015

Restructuring Cost and Reserve [Line Items]

Business separation costs

$ 0

$ 0

$ 0

$ 30.2

$ 21.7

[1]

$ 9.5

[1]

$ 7.4

[1]

$ 12

[1]

$ 30.2

[1]

$ 50.6

[1]

$ 7.5

Business separation additional income tax expense

51.8

Foreign earnings repatriated

443.8

Loss on extinguishment of debt

6.9

[2]

$ 0

[2]

$ 0

[2]

$ 0

[2]

0

6.9

[2]

16.6

Versum Financing

Restructuring Cost and Reserve [Line Items]

Cash to be received at spin-off

$ 550

550

550

Senior notes

425

$ 425

425

Extinguishment of debt amount

418.3

Loss on extinguishment of debt

$ 6.9

6.9

Performance Materials Division (PMD) | Maximum

Restructuring Cost and Reserve [Line Items]

Transition services agreement timeframe not to exceed (in months)

12 months

Materials Technologies

Restructuring Cost and Reserve [Line Items]

Business separation costs

30.2

50.6

$ 7.5

Electronic Materials Division (EMD)

Restructuring Cost and Reserve [Line Items]

Tax benefit related to changes in tax positions on business separation activities

$ 5.5

Business separation additional income tax expense

51.8

Tax expense related to repatriation of foreign earnings

45.7

Foreign earnings repatriated

$ 443.8

[1]

For additional information, see Note 4, Materials Technologies Separation.

[2]

For additional information, see Note 15, Debt.

Business Restructuring and Co65

Business Restructuring and Cost Reduction Actions (Narrative) (Details) $ in Millions

3 Months Ended

12 Months Ended

Sep. 30, 2017USD ($)

[1]

Jun. 30, 2017USD ($)

[1]

Mar. 31, 2017USD ($)

[1]

Dec. 31, 2016USD ($)

[1]

Sep. 30, 2016USD ($)

[1]

Jun. 30, 2016USD ($)

[1]

Mar. 31, 2016USD ($)

[1]

Dec. 31, 2015USD ($)

[1]

Sep. 30, 2014USD ($)position

Sep. 30, 2017USD ($)position

Sep. 30, 2016USD ($)position

Sep. 30, 2015USD ($)position

Sep. 30, 2014USD ($)

Restructuring and Related Cost [Abstract]

Business restructuring and cost reduction actions

$ 48.4

$ 42.7

$ 10.3

$ 50

$ 10.6

$ 13.2

$ 10.7

$ 0

$ 151.4

[1]

$ 34.5

[1]

$ 180.1

Cost Reduction Actions

Restructuring and Related Cost [Abstract]

Business restructuring and cost reduction actions

154.8

34.5

Cost Reduction Actions | Industrial Gases - Americas

Restructuring and Related Cost [Abstract]

Business restructuring and cost reduction actions

39.3

Cost Reduction Actions | Industrial Gases - EMEA

Restructuring and Related Cost [Abstract]

Business restructuring and cost reduction actions

77.9

Cost Reduction Actions | Industrial Gases - Asia

Restructuring and Related Cost [Abstract]

Business restructuring and cost reduction actions

0.9

Cost Reduction Actions | Industrial Gases - Global

Restructuring and Related Cost [Abstract]

Business restructuring and cost reduction actions

2.5

Cost Reduction Actions | Corporate and Other

Restructuring and Related Cost [Abstract]

Business restructuring and cost reduction actions

34.2

Cost Reduction Actions | Severance and Other Benefits

Restructuring and Related Cost [Abstract]

Business restructuring and cost reduction actions

$ 66.3

$ 34.5

Number of positions eliminated | position

625

610

Cost Reduction Actions | Asset Actions/Other

Restructuring and Related Cost [Abstract]

Business restructuring and cost reduction actions

$ 88.5

$ 0

Business Realignment and Reorganization

Restructuring and Related Cost [Abstract]

Business restructuring and cost reduction actions

180.1

$ 11.1

Favorable restructuring reserve settlement

3.4

Business Realignment and Reorganization | Industrial Gases - Americas

Restructuring and Related Cost [Abstract]

Business restructuring and cost reduction actions

31.7

Business Realignment and Reorganization | Industrial Gases - EMEA

Restructuring and Related Cost [Abstract]

Business restructuring and cost reduction actions

52.2

Business Realignment and Reorganization | Industrial Gases - Asia

Restructuring and Related Cost [Abstract]

Business restructuring and cost reduction actions

10.3

Business Realignment and Reorganization | Industrial Gases - Global

Restructuring and Related Cost [Abstract]

Business restructuring and cost reduction actions

37

Business Realignment and Reorganization | Corporate and Other

Restructuring and Related Cost [Abstract]

Business restructuring and cost reduction actions

48.9

Business Realignment and Reorganization | Severance and Other Benefits

Restructuring and Related Cost [Abstract]

Business restructuring and cost reduction actions

$ 11.1

$ 131.5

11.1

Favorable restructuring reserve settlement

0

Number of positions eliminated | position

40

1,700

Business Realignment and Reorganization | Asset Actions/Other

Restructuring and Related Cost [Abstract]

Business restructuring and cost reduction actions

$ 48.6

$ 0

Favorable restructuring reserve settlement

$ 3.4

[1]

For additional information, see Note 5, Business Restructuring and Cost Reduction Actions.

Business Restructuring and Co66

Business Restructuring and Cost Reduction Actions (Carrying Amount of Accrual) (Details) - USD ($) $ in Millions	3 Months Ended																	12 Months Ended
	Sep. 30, 2017		Jun. 30, 2017	[1]	Mar. 31, 2017	[1]	Dec. 31, 2016	[1]	Sep. 30, 2016		Jun. 30, 2016	[1]	Mar. 31, 2016	[1]	Dec. 31, 2015	[1]	Sep. 30, 2014	Sep. 30, 2017		Sep. 30, 2016		Sep. 30, 2015	Sep. 30, 2014
Restructuring Cost and Reserve [Line Items]
Business restructuring and cost reduction actions	$ 48.4	[1]	$ 42.7		$ 10.3		$ 50		$ 10.6	[1]	$ 13.2		$ 10.7		$ 0			$ 151.4	[1]	$ 34.5	[1]	$ 180.1
Cost Reduction Actions
Restructuring Cost and Reserve [Line Items]
Business restructuring and cost reduction actions																		154.8		34.5
Noncash expenses																		(84.2)
Amount reflected in pension liability																		(2)		(0.9)
Amount reflected in other noncurrent liabilities																		(2.2)
Cash expenditures																		(36.9)		(21.6)
Currency translation adjustment																		(0.3)		0.3
Accrued Balance	41.5								12.3									41.5		12.3
Cost Reduction Actions | Severance and Other Benefits
Restructuring Cost and Reserve [Line Items]
Business restructuring and cost reduction actions																		66.3		34.5
Noncash expenses																		0
Amount reflected in pension liability																		(2)		(0.9)
Amount reflected in other noncurrent liabilities																		0
Cash expenditures																		(35.7)		(21.6)
Currency translation adjustment																		(0.3)		0.3
Accrued Balance	40.6								12.3									40.6		12.3
Cost Reduction Actions | Asset Actions/Other
Restructuring Cost and Reserve [Line Items]
Business restructuring and cost reduction actions																		88.5		0
Noncash expenses																		(84.2)
Amount reflected in pension liability																		0		0
Amount reflected in other noncurrent liabilities																		(2.2)
Cash expenditures																		(1.2)		0
Currency translation adjustment																		0		0
Accrued Balance	0.9								0									0.9		0
Business Realignment and Reorganization
Restructuring Cost and Reserve [Line Items]
Business restructuring and cost reduction actions																						180.1	$ 11.1
Noncash expenses																						(40.2)
Amount reflected in pension liability																						(11.2)
Cash expenditures																				(32.4)		(101.5)	(1.7)
Currency translation adjustment																				(0.4)		(0.4)
Favorable restructuring reserve settlement																		(3.4)
Accrued Balance	0								3.4								$ 9.4	0		3.4		36.2	9.4
Business Realignment and Reorganization | Severance and Other Benefits
Restructuring Cost and Reserve [Line Items]
Business restructuring and cost reduction actions																	11.1					131.5	11.1
Noncash expenses																						0
Amount reflected in pension liability																						(11.2)
Cash expenditures																				(28.6)		(100.3)	(1.7)
Currency translation adjustment																				(0.4)		(0.4)
Favorable restructuring reserve settlement																		0
Accrued Balance	0								0								9.4	0		0		29	9.4
Business Realignment and Reorganization | Asset Actions/Other
Restructuring Cost and Reserve [Line Items]
Business restructuring and cost reduction actions																						48.6	0
Noncash expenses																						(40.2)
Amount reflected in pension liability																						0
Cash expenditures																				(3.8)		(1.2)	0
Currency translation adjustment																				0		0
Favorable restructuring reserve settlement																		(3.4)
Accrued Balance	$ 0								$ 3.4								$ 0	$ 0		$ 3.4		$ 7.2	$ 0
[1]	For additional information, see Note 5, Business Restructuring and Cost Reduction Actions.

Business Combination (Narrative

Business Combination (Narrative) (Details) - USD ($) $ in Millions	Dec. 30, 2014	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2015
Business Acquisition [Line Items]
Acquisitions, less cash acquired		$ 8.2	$ 0	$ 34.5
Gain on previously held equity interest		$ 0	$ 0	17.9
Production Joint Venture
Business Acquisition [Line Items]
Acquisitions, less cash acquired	$ 22.6
Percent ownership before acquisition	50.00%
Percent ownership after acquisition	100.00%
Gain on previously held equity interest				$ 17.9

Inventories (Narrative) (Detail

Inventories (Narrative) (Details)	Sep. 30, 2017	Sep. 30, 2016
Inventory Disclosure [Abstract]
Percentage of LIFO Inventory	48.70%	22.90%

Inventories (Schedule of Invent

Inventories (Schedule of Inventory) (Details) - USD ($) $ in Millions	Sep. 30, 2017	Sep. 30, 2016
Inventory Disclosure [Abstract]
Finished goods	$ 120	$ 131.3
Work in process	15.7	18.3
Raw materials, supplies and other	223	117.1
Total FIFO Cost	358.7	266.7
Less: Excess of FIFO cost over LIFO cost	(23.3)	(11.7)
Inventories	$ 335.4	$ 255

Summarized Financial Informat70

Summarized Financial Information of Equity Affiliates (Narrative) (Details) - USD ($) $ in Millions		Apr. 19, 2015	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2015
Schedule of Equity Method Investments [Line Items]
Dividends received from equity affiliates											$ 99.5	$ 95.9	$ 50.5
Investment in net assets of and advances to equity affiliates			$ 1,286.9				$ 1,283.6				1,286.9	1,283.6
Goodwill associated with affiliate companies accounted for by equity method			45.8				109.5				45.8	109.5
Equity method investment impairment charge				$ 79.5							79.5	0	0
Obligation for future contribution to equity affiliate			94.4				94.4				94.4	94.4
Sales			2,203.1	$ 2,121.9	$ 1,980.1	$ 1,882.5	1,945.5	$ 1,914.5	$ 1,777.4	$ 1,866.3	8,187.6	7,503.7	7,824.3
Foreign Affiliate
Schedule of Equity Method Investments [Line Items]
Investment in net assets of and advances to equity affiliates			$ 1,285.1				1,281.5				$ 1,285.1	1,281.5
Abdullah Hashim Industrial Gases & Equipment Co., Ltd.
Schedule of Equity Method Investments [Line Items]
Ownership interest percentage			25.00%								25.00%
Equity method investment impairment charge	[1]										$ 79.5
Equity method investment carrying value			$ 66.7								$ 66.7
Abdullah Hashim Industrial Gases & Equipment Co., Ltd. | Industrial Gases - EMEA
Schedule of Equity Method Investments [Line Items]
Ownership interest percentage				25.00%
Jazan Gas Projects Company
Schedule of Equity Method Investments [Line Items]
Ownership interest percentage			25.00%								25.00%
Oxygen and nitrogen supply agreement, term		20 years
Obligation for future contribution to equity affiliate			$ 94.4				$ 94.4				$ 94.4	94.4
Noncash transaction, increase to investment											0	26.9	$ 67.5
Total expected investment			$ 100								100
Jazan Gas Projects Company | Industrial Gases - Global
Schedule of Equity Method Investments [Line Items]
Sales											$ 540	$ 300
[1]	We assessed the recoverability of the carrying value of our equity investment in AHG. We estimated the fair value of our investment using weighting of the results of the income and market approaches. An impairment loss was recognized for the difference between the carrying amount and the fair value of the investment as of 30 June 2017. There have been no updates to our estimates as of 30 September 2017. For additional information, see Note 8, Summarized Financial Information of Equity Affiliates.

Summarized Financial Informat71

Summarized Financial Information of Equity Affiliates (Investment Listing) (Details)	Sep. 30, 2017
Abdullah Hashim Industrial Gases & Equipment Co., Ltd.
Schedule of Equity Method Investments [Line Items]
Ownership interest percentage	25.00%
Air Products South Africa (Proprietary) Limited
Schedule of Equity Method Investments [Line Items]
Ownership interest percentage	50.00%
Bangkok Cogeneration Company Limited
Schedule of Equity Method Investments [Line Items]
Ownership interest percentage	49.00%
Bangkok Industrial Gases Co., Ltd.
Schedule of Equity Method Investments [Line Items]
Ownership interest percentage	49.00%
Chengdu Air & Gas Products Ltd.
Schedule of Equity Method Investments [Line Items]
Ownership interest percentage	50.00%
Helios S.p.A.
Schedule of Equity Method Investments [Line Items]
Ownership interest percentage	49.00%
High-Tech Gases (Beijing) Co., Ltd.
Schedule of Equity Method Investments [Line Items]
Ownership interest percentage	50.00%
INFRA Group
Schedule of Equity Method Investments [Line Items]
Ownership interest percentage	40.00%
INOX Air Products Limited
Schedule of Equity Method Investments [Line Items]
Ownership interest percentage	50.00%
Jazan Gas Projects Company
Schedule of Equity Method Investments [Line Items]
Ownership interest percentage	25.00%
Kulim Industrial Gases Sdn. Bhd.
Schedule of Equity Method Investments [Line Items]
Ownership interest percentage	50.00%
Sapio Produzione Idrogeno Ossigeno S.r.l.
Schedule of Equity Method Investments [Line Items]
Ownership interest percentage	49.00%
Tecnologia en Nitrogeno S. de R.L. de C.V.
Schedule of Equity Method Investments [Line Items]
Ownership interest percentage	50.00%
Tyczka Industrie-Gases GmbH
Schedule of Equity Method Investments [Line Items]
Ownership interest percentage	50.00%
WuXi Hi-Tech Gas Co., Ltd.
Schedule of Equity Method Investments [Line Items]
Ownership interest percentage	50.00%

Summarized Financial Informat72

Summarized Financial Information of Equity Affiliates (Table of Summarized Financial Information of Equity Affiliates) (Details) - USD ($) $ in Millions	12 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2015
Summarized Financial Information, Balance Sheet
Current assets	$ 1,333.2	$ 1,436.7
Noncurrent assets	4,026.9	3,063.3
Current liabilities	666.8	694.8
Noncurrent liabilities	2,194.3	1,540.4
Summarized Financial Information, Income Statement
Net sales	2,343.3	2,271.6	$ 2,460.5
Sales less cost of sales	878.6	871.5	922.7
Operating income	509.5	482.1	512.4
Net income	$ 343.5	$ 334.1	$ 343.5

Plant and Equipment, Net (Major

Plant and Equipment, Net (Major Classes of Plant and Equipment) (Details) - USD ($) $ in Millions		12 Months Ended
		Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2015
Property, Plant and Equipment [Line Items]
Plant and equipment, at cost		$ 19,547.8	$ 18,660.2
Less: accumulated depreciation		11,107.6	10,400.5
Plant and equipment, net	[1]	8,440.2	8,259.7	$ 8,237.3
Land
Property, Plant and Equipment [Line Items]
Plant and equipment, at cost		231	202.9
Buildings
Property, Plant and Equipment [Line Items]
Plant and equipment, at cost		$ 977.8	918.6
Useful life (in years)		30 years
Production facilities
Property, Plant and Equipment [Line Items]
Plant and equipment, at cost	[2]	$ 13,577.1	12,391.9
Production facilities | Minimum
Property, Plant and Equipment [Line Items]
Useful life (in years)	[2]	10 years
Production facilities | Maximum
Property, Plant and Equipment [Line Items]
Useful life (in years)	[2]	20 years
Distribution and other machinery and equipment
Property, Plant and Equipment [Line Items]
Plant and equipment, at cost	[3]	$ 3,944	3,821
Distribution and other machinery and equipment | Minimum
Property, Plant and Equipment [Line Items]
Useful life (in years)	[3]	5 years
Distribution and other machinery and equipment | Maximum
Property, Plant and Equipment [Line Items]
Useful life (in years)	[3]	25 years
Cylinders | Minimum
Property, Plant and Equipment [Line Items]
Useful life (in years)		10 years
Cylinders | Maximum
Property, Plant and Equipment [Line Items]
Useful life (in years)		25 years
Tanks
Property, Plant and Equipment [Line Items]
Useful life (in years)		20 years
Customer Stations
Property, Plant and Equipment [Line Items]
Useful life (in years)		7 years 6 months
Tractors and Trailers | Minimum
Property, Plant and Equipment [Line Items]
Useful life (in years)		5 years
Tractors and Trailers | Maximum
Property, Plant and Equipment [Line Items]
Useful life (in years)		15 years
Construction in progress
Property, Plant and Equipment [Line Items]
Plant and equipment, at cost		$ 817.9	$ 1,325.8
[1]	Long-lived assets include plant and equipment, net.
[2]	Depreciable lives of production facilities related to long-term customer supply contracts are matched to the contract lives.
[3]	The depreciable lives for various types of distribution equipment are 10 to 25 years for cylinders, depending on the nature and properties of the product; 20 years for tanks; 7.5 years for customer stations; and 5 to 15 years for tractors and trailers.

Plant and Equipment, Net (Narra

Plant and Equipment, Net (Narrative) (Details) - USD ($) $ in Millions	12 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2015
Property, Plant and Equipment [Abstract]
Depreciation expense	$ 843.2	$ 832.3	$ 834.5

Goodwill (Schedule of Goodwill

Goodwill (Schedule of Goodwill by Segment) (Details) - USD ($) $ in Millions	9 Months Ended	12 Months Ended
	Jun. 30, 2017	Sep. 30, 2017	Sep. 30, 2016
Goodwill [Roll Forward]
Goodwill, net, beginning balance	$ 845.1	$ 845.1	$ 837.1
Impairment loss	(145.3)	(145.3)
Acquisitions		3.5
Currency translation		18.2	8
Goodwill, net, ending balance		721.5	845.1
Industrial Gases - Americas
Goodwill [Roll Forward]
Goodwill, net, beginning balance	309.1	309.1	297.6
Impairment loss		(145.3)
Acquisitions		0
Currency translation		(0.1)	11.5
Goodwill, net, ending balance		163.7	309.1
Industrial Gases - EMEA
Goodwill [Roll Forward]
Goodwill, net, beginning balance	380.6	380.6	386.5
Impairment loss		0
Acquisitions		3.5
Currency translation		18.3	(5.9)
Goodwill, net, ending balance		402.4	380.6
Industrial Gases - Asia
Goodwill [Roll Forward]
Goodwill, net, beginning balance	135.2	135.2	133.1
Impairment loss		0
Acquisitions		0
Currency translation		0	2.1
Goodwill, net, ending balance		135.2	135.2
Industrial Gases - Global
Goodwill [Roll Forward]
Goodwill, net, beginning balance	$ 20.2	20.2	19.9
Impairment loss		0
Acquisitions		0
Currency translation		0	0.3
Goodwill, net, ending balance		$ 20.2	$ 20.2

Goodwill (Schedule of Accumulat

Goodwill (Schedule of Accumulated Impairment Losses) (Details) - USD ($) $ in Millions	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2015
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill, gross	$ 1,138.7	$ 1,103.7	$ 1,080.8
Accumulated impairment losses	(417.2)	(258.6)	(243.7)
Goodwill, net	$ 721.5	$ 845.1	$ 837.1

Goodwill (Narrative) (Details)

Goodwill (Narrative) (Details) - USD ($) $ in Millions	9 Months Ended	12 Months Ended
	Jun. 30, 2017	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2015
Goodwill [Line Items]
Goodwill impairment charge	$ 145.3	$ 145.3
Goodwill accumulated impairment losses		417.2	$ 258.6	$ 243.7
Industrial Gases - Americas
Goodwill [Line Items]
Goodwill impairment charge		145.3
Goodwill accumulated impairment losses		$ 417.2

Intangible Assets (Narrative) (

Intangible Assets (Narrative) (Details) - USD ($) $ in Millions	9 Months Ended	12 Months Ended
	Jun. 30, 2017	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2015
Goodwill and Intangible Assets Disclosure [Abstract]
Amortization expense for intangible assets		$ 22.6	$ 22.3	$ 24
Intangible asset impairment charge	$ 16.8

Intangible Assets (Acquired Int

Intangible Assets (Acquired Intangible Assets) (Details) - USD ($) $ in Millions	Sep. 30, 2017	Sep. 30, 2016
Goodwill and Intangible Assets Disclosure [Abstract]
Intangible assets, gross	$ 578.7	$ 553.4
Accumulated amortization and impairment	(210.4)	(165.5)
Intangible assets, net	368.3	387.9
Acquired Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible assets, gross	510.9	487.2
Accumulated amortization	(189.5)	(162)
Finite-lived intangible assets, net	321.4	325.2
Trade Names and Trademarks
Acquired Indefinite-lived Intangible Assets [Line Items]
Indefinite-lived intangible assets, gross	67.8	66.2
Accumulated impairment	(20.9)	(3.5)
Indefinite-lived intangible assets, net	46.9	62.7
Customer Relationships
Acquired Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible assets, gross	424.1	400.6
Accumulated amortization	(142.3)	(118.2)
Finite-lived intangible assets, net	281.8	282.4
Patents and Technology
Acquired Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible assets, gross	13.4	13.6
Accumulated amortization	(10.6)	(10.1)
Finite-lived intangible assets, net	2.8	3.5
Other
Acquired Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible assets, gross	73.4	73
Accumulated amortization	(36.6)	(33.7)
Finite-lived intangible assets, net	$ 36.8	$ 39.3

Intangible Assets (Projected An

Intangible Assets (Projected Annual Amortization Expense for Intangible Assets) (Details) - USD ($) $ in Millions	Sep. 30, 2017	Sep. 30, 2016
Goodwill and Intangible Assets Disclosure [Abstract]
2,018	$ 22.1
2,019	21.8
2,020	21.6
2,021	20.1
2,022	17.4
Thereafter	218.4
Total future amortization expense	$ 321.4	$ 325.2

Leases (Narrative) (Details)

Leases (Narrative) (Details) - USD ($) $ in Millions	12 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2015
Leases [Abstract]
Capital leases, plant and equipment	$ 22.3	$ 22.4
Capital leases, accumulated depreciation	5.3	4.5
Operating leases, rent expense	65.8	67.6	$ 70.4
Future capital lease payment present value	10.8
Lessor, total lease payments collected	183.6	186	146.6
Lessor, collection of lease receivables	$ 92.2	$ 85.5	$ 68.8

Leases (Energy-from-Waste Narra

Leases (Energy-from-Waste Narrative) (Details) $ in Millions	Sep. 30, 2017USD ($)
Operating Leases
2,018	$ 56.6
2,019	45.8
2,020	35.2
2,021	27.1
2,022	22.9
Thereafter	126.6
Total	314.2
Energy-from-Waste (EfW)
Operating Leases
2,018	2
2,019	2
2,020	2
2,021	2
2,022	2
Thereafter	40
Total	$ 50

Leases (Minimum Payments Due) (

Leases (Minimum Payments Due) (Details) $ in Millions	Sep. 30, 2017USD ($)
Capital Leases
2,018	$ 2.2
2,019	1.8
2,020	1.6
2,021	3
2,022	1.5
Thereafter	19.9
Total	30
Operating Leases
2,018	56.6
2,019	45.8
2,020	35.2
2,021	27.1
2,022	22.9
Thereafter	126.6
Total	$ 314.2

Leases (Lease Receivables) (Det

Leases (Lease Receivables) (Details) - USD ($) $ in Millions	Sep. 30, 2017	Sep. 30, 2016
Leases [Abstract]
Gross minimum lease payments receivable	$ 1,897	$ 2,072.6
Unearned interest income	(671.9)	(762.7)
Lease Receivables, net	$ 1,225.1	$ 1,309.9

Leases (Minimum Lease Payments

Leases (Minimum Lease Payments Receivable) (Details) $ in Millions	Sep. 30, 2017USD ($)
Minimum Lease Payments Receivable
2,018	$ 182
2,019	176.4
2,020	171.4
2,021	165.5
2,022	154.1
Thereafter	1,047.6
Total	$ 1,897

Financial Instruments (Narrativ

Financial Instruments (Narrative) (Details) € in Millions	12 Months Ended
	Sep. 30, 2017USD ($)	Sep. 30, 2017EUR (€)	Sep. 30, 2016USD ($)	Sep. 30, 2016EUR (€)
Derivative [Line Items]
Net liability position of derivatives with credit risk-related contingent features	$ 34,600,000		$ 11,200,000
Collateral posted on liability positions with credit risk-related features	0
Collateral amount that counterparties would be required to post	$ 138,500,000		267,600,000
Forward Exchange Contracts | Cash Flow Hedges
Derivative [Line Items]
Maximum remaining maturity of foreign currency derivatives	1 year 10 months	1 year 10 months
Foreign Currency Debt | Euro Denominated
Derivative [Line Items]
Notional amount included in designated foreign currency denominated debt	$ 1,077,700,000	€ 912.2	$ 1,034,400,000	€ 920.7

Financial Instruments (Schedule

Financial Instruments (Schedule of Outstanding Currency Price Risk Management Instruments) (Details) - Forward Exchange Contracts - USD ($) $ in Millions	12 Months Ended
	Sep. 30, 2017	Sep. 30, 2016
Derivative [Line Items]
US$ Notional	$ 4,099.5	$ 7,746.8
Years Average Maturity	10 months	8 months
Designated as Hedging Instrument | Cash Flow Hedges
Derivative [Line Items]
US$ Notional	$ 3,150.2	$ 4,130.3
Years Average Maturity	5 months	6 months
Designated as Hedging Instrument | Net Investment Hedges
Derivative [Line Items]
US$ Notional	$ 675.5	$ 968.2
Years Average Maturity	3 years	2 years 8 months
Not Designated as Hedging Instrument
Derivative [Line Items]
US$ Notional	$ 273.8	$ 2,648.3
Years Average Maturity	1 month	5 months

Financial Instruments (Schedu88

Financial Instruments (Schedule of Interest Rate Swaps and Cross Currency Interest Rate Swaps) (Details) - USD ($) $ in Millions	12 Months Ended
	Sep. 30, 2017	Sep. 30, 2016
Interest Rate Swaps Contracts | Designated as Hedging Instrument | Fair Value Hedges
Derivative [Line Items]
US$ Notional	$ 600	$ 600
Average Pay %	LIBOR	LIBOR
Average Receive %	2.28%	2.28%
Years Average Maturity	1 year 4 months	2 years 4 months
Cross Currency Interest Rate Swaps | Designated as Hedging Instrument | Net Investment Hedges
Derivative [Line Items]
US$ Notional	$ 539.7	$ 517.7
Average Pay %	3.27%	3.24%
Average Receive %	2.59%	2.43%
Years Average Maturity	1 year 11 months	2 years 7 months
Cross Currency Interest Rate Swaps | Designated as Hedging Instrument | Cash Flow Hedges
Derivative [Line Items]
US$ Notional	$ 1,095.7	$ 1,088.9
Average Pay %	4.96%	4.77%
Average Receive %	2.78%	2.72%
Years Average Maturity	2 years 5 months	3 years 4 months
Cross Currency Interest Rate Swaps | Not Designated as Hedging Instrument
Derivative [Line Items]
US$ Notional	$ 41.6	$ 27.4
Average Pay %	3.28%	3.62%
Average Receive %	2.32%	0.81%
Years Average Maturity	1 year 8 months	1 year 10 months

Financial Instruments (Fair Val

Financial Instruments (Fair Value of Derivative Instruments) (Details) - USD ($) $ in Millions	Sep. 30, 2017	Sep. 30, 2016
Derivative [Line Items]
Total Derivatives, Assets	$ 227.8	$ 373.7
Total Derivatives, Liabilities	131.9	95.3
Designated as Hedging Instrument
Derivative [Line Items]
Total Derivatives, Assets	222.5	296.6
Total Derivatives, Liabilities	128.7	65.1
Not Designated as Hedging Instrument
Derivative [Line Items]
Total Derivatives, Assets	5.3	77.1
Total Derivatives, Liabilities	3.2	30.2
Forward Exchange Contracts | Designated as Hedging Instrument | Other Receivables
Derivative [Line Items]
Total Derivatives, Assets	81.7	72.3
Forward Exchange Contracts | Designated as Hedging Instrument | Other Noncurrent Assets
Derivative [Line Items]
Total Derivatives, Assets	27.1	44.4
Forward Exchange Contracts | Designated as Hedging Instrument | Accrued Liabilities
Derivative [Line Items]
Total Derivatives, Liabilities	82	44
Forward Exchange Contracts | Designated as Hedging Instrument | Other Noncurrent Liabilities
Derivative [Line Items]
Total Derivatives, Liabilities	13.8	9.1
Forward Exchange Contracts | Not Designated as Hedging Instrument | Other Receivables
Derivative [Line Items]
Total Derivatives, Assets	1.1	77.1
Forward Exchange Contracts | Not Designated as Hedging Instrument | Accrued Liabilities
Derivative [Line Items]
Total Derivatives, Liabilities	2.2	29.5
Interest Rate Management Contract | Designated as Hedging Instrument | Other Receivables
Derivative [Line Items]
Total Derivatives, Assets	11.1	19.9
Interest Rate Management Contract | Designated as Hedging Instrument | Other Noncurrent Assets
Derivative [Line Items]
Total Derivatives, Assets	102.6	160
Interest Rate Management Contract | Designated as Hedging Instrument | Accrued Liabilities
Derivative [Line Items]
Total Derivatives, Liabilities	10.7	0
Interest Rate Management Contract | Designated as Hedging Instrument | Other Noncurrent Liabilities
Derivative [Line Items]
Total Derivatives, Liabilities	22.2	12
Interest Rate Management Contract | Not Designated as Hedging Instrument | Other Receivables
Derivative [Line Items]
Total Derivatives, Assets	0	0
Interest Rate Management Contract | Not Designated as Hedging Instrument | Other Noncurrent Assets
Derivative [Line Items]
Total Derivatives, Assets	4.2	0
Interest Rate Management Contract | Not Designated as Hedging Instrument | Accrued Liabilities
Derivative [Line Items]
Total Derivatives, Liabilities	1	0
Interest Rate Management Contract | Not Designated as Hedging Instrument | Other Noncurrent Liabilities
Derivative [Line Items]
Total Derivatives, Liabilities	$ 0	$ 0.7

Financial Instruments (Schedu90

Financial Instruments (Schedule of Gain/Loss Related to Derivative Instruments) (Details) - USD ($) $ in Millions		12 Months Ended
		Sep. 30, 2017	Sep. 30, 2016
Designated as Hedging Instrument | Cash Flow Hedges
Derivative [Line Items]
Net gain (loss) recognized in OCI (effective portion)		$ (12.6)	$ 13.7
Net (gain) loss reclassified from OCI to sales/cost of sales (effective portion)		18.3	0.2
Net (gain) loss reclassified from OCI to other income (expense), net (effective portion)		6.7	(46)
Net (gain) loss reclassified from OCI to interest expense (effective portion)		0.8	10
Net (gain) loss reclassified from OCI to other income (expense), net (ineffective portion)		(1.6)	(0.2)
Designated as Hedging Instrument | Fair Value Hedges
Derivative [Line Items]
Net (gain) loss recognized in interest expense	[1]	(14.7)	(8.8)
Designated as Hedging Instrument | Net Investment Hedges
Derivative [Line Items]
Net gain (loss) recognized in OCI		(59.5)	42.8
Not Designated as Hedging Instrument
Derivative [Line Items]
Net gain (loss) recognized in other income (expense)	[2]	1.7	(3.4)
Forward Exchange Contracts | Designated as Hedging Instrument | Cash Flow Hedges
Derivative [Line Items]
Net gain (loss) recognized in OCI (effective portion)		0.3	10.5
Net (gain) loss reclassified from OCI to sales/cost of sales (effective portion)		18.3	0.2
Net (gain) loss reclassified from OCI to other income (expense), net (effective portion)		(3.8)	(25.7)
Net (gain) loss reclassified from OCI to interest expense (effective portion)		(2.1)	6.7
Net (gain) loss reclassified from OCI to other income (expense), net (ineffective portion)		(1.6)	(0.2)
Forward Exchange Contracts | Designated as Hedging Instrument | Fair Value Hedges
Derivative [Line Items]
Net (gain) loss recognized in interest expense	[1]	0	0
Forward Exchange Contracts | Designated as Hedging Instrument | Net Investment Hedges
Derivative [Line Items]
Net gain (loss) recognized in OCI		(11.1)	17.4
Forward Exchange Contracts | Not Designated as Hedging Instrument
Derivative [Line Items]
Net gain (loss) recognized in other income (expense)	[2]	4.1	(1.8)
Foreign Currency Debt | Designated as Hedging Instrument | Net Investment Hedges
Derivative [Line Items]
Net gain (loss) recognized in OCI		(32.8)	(9.6)
Other Contracts | Designated as Hedging Instrument | Cash Flow Hedges
Derivative [Line Items]
Net gain (loss) recognized in OCI (effective portion)	[3]	(12.9)	3.2
Net (gain) loss reclassified from OCI to sales/cost of sales (effective portion)	[3]	0	0
Net (gain) loss reclassified from OCI to other income (expense), net (effective portion)	[3]	10.5	(20.3)
Net (gain) loss reclassified from OCI to interest expense (effective portion)	[3]	2.9	3.3
Net (gain) loss reclassified from OCI to other income (expense), net (ineffective portion)	[3]	0	0
Other Contracts | Designated as Hedging Instrument | Fair Value Hedges
Derivative [Line Items]
Net (gain) loss recognized in interest expense	[1],[3]	(14.7)	(8.8)
Other Contracts | Designated as Hedging Instrument | Net Investment Hedges
Derivative [Line Items]
Net gain (loss) recognized in OCI	[3]	(15.6)	35
Other Contracts | Not Designated as Hedging Instrument
Derivative [Line Items]
Net gain (loss) recognized in other income (expense)	[2],[3]	$ (2.4)	$ (1.6)
[1]	The impact of fair value hedges noted above was largely offset by recognized gains and losses resulting from the impact of changes in related interest rates on outstanding debt.
[2]	The impact of the non-designated hedges noted above was largely offset by recognized gains and losses resulting from the impact of changes in exchange rates on assets and liabilities denominated in nonfunctional currencies.
[3]	Other includes the impact on other comprehensive income (OCI) and earnings primarily related to interest rate and cross currency interest rate swaps.

Fair Value Measurements (Schedu

Fair Value Measurements (Schedule of the Carrying Values and Fair Values of Financial Instruments) (Details) - USD ($) $ in Millions	Sep. 30, 2017	Sep. 30, 2016
Carrying Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt, including current portion carrying value	$ 3,818.8	$ 4,275.1
Fair Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt, including current portion fair value	3,928.2	4,474
Forward Exchange Contracts | Carrying Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative assets	109.9	193.8
Derivative liabilities	98	82.6
Forward Exchange Contracts | Fair Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative assets	109.9	193.8
Derivative liabilities	98	82.6
Interest Rate Management Contract | Carrying Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative assets	117.9	179.9
Derivative liabilities	33.9	12.7
Interest Rate Management Contract | Fair Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative assets	117.9	179.9
Derivative liabilities	$ 33.9	$ 12.7

Fair Value Measurements (Sche92

Fair Value Measurements (Schedule of Recurring Fair Value Measurements) (Details) - Fair Value, Measurements, Recurring - USD ($) $ in Millions	Sep. 30, 2017	Sep. 30, 2016
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total Assets at Fair Value	$ 227.8	$ 373.7
Total Liabilities at Fair Value	131.9	95.3
Level 1
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total Assets at Fair Value	0	0
Total Liabilities at Fair Value	0	0
Level 2
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total Assets at Fair Value	227.8	373.7
Total Liabilities at Fair Value	131.9	95.3
Level 3
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total Assets at Fair Value	0	0
Total Liabilities at Fair Value	0	0
Forward Exchange Contracts
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative assets	109.9	193.8
Derivative liabilities	98	82.6
Forward Exchange Contracts | Level 1
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative assets	0	0
Derivative liabilities	0	0
Forward Exchange Contracts | Level 2
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative assets	109.9	193.8
Derivative liabilities	98	82.6
Forward Exchange Contracts | Level 3
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative assets	0	0
Derivative liabilities	0	0
Interest Rate Management Contract
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative assets	117.9	179.9
Derivative liabilities	33.9	12.7
Interest Rate Management Contract | Level 1
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative assets	0	0
Derivative liabilities	0	0
Interest Rate Management Contract | Level 2
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative assets	117.9	179.9
Derivative liabilities	33.9	12.7
Interest Rate Management Contract | Level 3
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative assets	0	0
Derivative liabilities	$ 0	$ 0

Fair Value Measurements (Sche93

Fair Value Measurements (Schedule of Nonrecurring Fair Value Measurements) (Details) - USD ($) $ in Millions		3 Months Ended	12 Months Ended
		Jun. 30, 2017	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2015	Dec. 31, 2016
Long Lived Assets Held-for-sale [Line Items]
Write-down of long-lived assets associated with restructuring			$ 69.2	$ 0	$ 40.2
Equity method investment impairment charge		$ 79.5	79.5	0	$ 0
Continuing Operations
Long Lived Assets Held-for-sale [Line Items]
Write-down of long-lived assets associated with restructuring	[1]		45.7	0
Discontinued Operations
Long Lived Assets Held-for-sale [Line Items]
Write-down of long-lived assets held for sale	[1]		6.3	$ 913.5
Fair Value, Measurements, Nonrecurring | Continuing Operations
Long Lived Assets Held-for-sale [Line Items]
Plant and Equipment – Continuing operations	[1]					$ 1.4
Fair Value, Measurements, Nonrecurring | Discontinued Operations
Long Lived Assets Held-for-sale [Line Items]
Plant and Equipment – Discontinued operations	[1]					11
Level 1 | Fair Value, Measurements, Nonrecurring | Continuing Operations
Long Lived Assets Held-for-sale [Line Items]
Plant and Equipment – Continuing operations	[1]					0
Level 1 | Fair Value, Measurements, Nonrecurring | Discontinued Operations
Long Lived Assets Held-for-sale [Line Items]
Plant and Equipment – Discontinued operations	[1]					0
Level 2 | Fair Value, Measurements, Nonrecurring | Continuing Operations
Long Lived Assets Held-for-sale [Line Items]
Plant and Equipment – Continuing operations	[1]					0
Level 2 | Fair Value, Measurements, Nonrecurring | Discontinued Operations
Long Lived Assets Held-for-sale [Line Items]
Plant and Equipment – Discontinued operations	[1]					0
Level 3 | Fair Value, Measurements, Nonrecurring | Continuing Operations
Long Lived Assets Held-for-sale [Line Items]
Plant and Equipment – Continuing operations	[1]					1.4
Level 3 | Fair Value, Measurements, Nonrecurring | Discontinued Operations
Long Lived Assets Held-for-sale [Line Items]
Plant and Equipment – Discontinued operations	[1]					$ 11
Abdullah Hashim Industrial Gases & Equipment Co., Ltd.
Long Lived Assets Held-for-sale [Line Items]
Equity method investment impairment charge	[2]		$ 79.5
Abdullah Hashim Industrial Gases & Equipment Co., Ltd. | Fair Value, Measurements, Nonrecurring
Long Lived Assets Held-for-sale [Line Items]
Investment in Equity Affiliate	[2]	68.5
Abdullah Hashim Industrial Gases & Equipment Co., Ltd. | Level 1 | Fair Value, Measurements, Nonrecurring
Long Lived Assets Held-for-sale [Line Items]
Investment in Equity Affiliate	[2]	0
Abdullah Hashim Industrial Gases & Equipment Co., Ltd. | Level 2 | Fair Value, Measurements, Nonrecurring
Long Lived Assets Held-for-sale [Line Items]
Investment in Equity Affiliate	[2]	0
Abdullah Hashim Industrial Gases & Equipment Co., Ltd. | Level 3 | Fair Value, Measurements, Nonrecurring
Long Lived Assets Held-for-sale [Line Items]
Investment in Equity Affiliate	[2]	$ 68.5
[1]	We assessed the recoverability of the carrying value of assets associated with the EfW discontinued operation, including the air separation unit within continuing operations of our Industrial Gases – EMEA segment. We based our estimates primarily on an orderly liquidation valuation which resulted in losses for the difference between the orderly liquidation value and net book value of the assets as of 31 December 2016 during fiscal year 2017. There have been no significant updates to our estimates as of 30 September 2017. For additional information, see Note 3, Discontinued Operations, and Note 5, Business Restructuring and Cost Reduction Actions.
[2]	We assessed the recoverability of the carrying value of our equity investment in AHG. We estimated the fair value of our investment using weighting of the results of the income and market approaches. An impairment loss was recognized for the difference between the carrying amount and the fair value of the investment as of 30 June 2017. There have been no updates to our estimates as of 30 September 2017. For additional information, see Note 8, Summarized Financial Information of Equity Affiliates.

Fair Value Measurements (Narrat

Fair Value Measurements (Narrative) (Details) - USD ($) $ in Millions	3 Months Ended	9 Months Ended	12 Months Ended
	Jun. 30, 2017	Jun. 30, 2017	Sep. 30, 2017
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Goodwill impairment charge		$ 145.3	$ 145.3
Intangible asset impairment charge		$ 16.8
Fair Value | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Goodwill impairment charge	$ 145.3
Intangible asset impairment charge	$ 16.8

Debt (Narrative) (Details)

Debt (Narrative) (Details)

Mar. 31, 2017USD ($)

Sep. 30, 2016USD ($)

Sep. 30, 2015USD ($)

Sep. 30, 2015CLF

Sep. 30, 2016USD ($)

Jun. 30, 2016USD ($)

[1]

Mar. 31, 2016USD ($)

[1]

Dec. 31, 2015USD ($)

[1]

Sep. 30, 2017USD ($)

Sep. 30, 2016USD ($)

Sep. 30, 2015USD ($)

Mar. 30, 2017USD ($)

Debt Disclosure [Abstract]

Short-term debt, weighted average interest rate

1.10%

1.10%

4.60%

1.10%

Cash paid for interest, net of amounts capitalized

$ 125,900,000

$ 120,600,000

$ 96,800,000

Debt Instrument [Line Items]

Loss on extinguishment of debt

$ 6,900,000

[1]

$ 0

$ 0

$ 0

0

6,900,000

[1]

16,600,000

Payments on long-term debt

483,900,000

480,400,000

$ 699,400,000

Versum Financing

Debt Instrument [Line Items]

Loss on extinguishment of debt

$ 6,900,000

6,900,000

Extinguishment of debt amount

$ 418,300,000

Foreign Line of Credit | Foreign Subsidiary Facility

Debt Instrument [Line Items]

Credit facility, amount borrowed and outstanding

23,400,000

Revolving Credit Facility | 2017 Credit Agreement

Debt Instrument [Line Items]

Credit facility, amount borrowed and outstanding

$ 0

Debt instrument, term

5 years

Maximum borrowing capacity

$ 2,500,000,000

Revolving Credit Facility | 2017 Credit Agreement | Maximum

Debt Instrument [Line Items]

Covenant, ratio of total debt to total capitalization

70.00%

Revolving Credit Facility | 2013 Credit Agreement

Debt Instrument [Line Items]

Credit facility, amount borrowed and outstanding

$ 0

Maximum borrowing capacity

$ 2,690,000,000

Early termination penalties

$ 0

Long-term Debt | CLP Series E bonds 6.3%

Debt Instrument [Line Items]

Loss on extinguishment of debt

$ 16,600,000

Payments on long-term debt

146,600,000

Extinguishment of debt amount

$ 130,000,000

CLF 3,000,000

Interest rate, stated percentage

6.30%

6.30%

6.30%

[1]

For additional information, see Note 15, Debt.

Debt (Summary of Outstanding De

Debt (Summary of Outstanding Debt) (Details) - USD ($) $ in Millions	Sep. 30, 2017	Sep. 30, 2016
Debt Disclosure [Abstract]
Short-term borrowings	$ 144	$ 935.8
Current portion of long-term debt	416.4	365.4
Long-term debt	3,402.4	3,909.7
Total Debt	$ 3,962.8	$ 5,210.9

Debt (Short-term Borrowings) (D

Debt (Short-term Borrowings) (Details) - USD ($) $ in Millions	Sep. 30, 2017	Sep. 30, 2016
Short-term Debt [Line Items]
Short-term borrowings	$ 144	$ 935.8
Bank Obligations
Short-term Debt [Line Items]
Short-term borrowings	144	133.1
Commercial Paper
Short-term Debt [Line Items]
Short-term borrowings	$ 0	$ 802.7

Debt (Long-term Debt) (Details)

Debt (Long-term Debt) (Details) - USD ($) $ in Millions	Sep. 30, 2017	Sep. 30, 2016
Debt Instrument [Line Items]
Long-term Debt, gross	$ 3,837.3	$ 4,298.5
Less: Unamortized Discount and Debt Issuance Costs	(18.5)	(23.4)
Total Long-term Debt	3,818.8	4,275.1
Less: Current portion of long-term debt	(416.4)	(365.4)
Long-term Debt	3,402.4	3,909.7
Debentures | Debenture 8.75% due 2021
Debt Instrument [Line Items]
Long-term Debt, gross	$ 18.4	18.4
Interest rate, stated percentage	8.75%
Medium-term Notes | Series E 7.6% due 2026
Debt Instrument [Line Items]
Long-term Debt, gross	$ 17.2	17.2
Interest rate, weighted average	7.60%
Senior Notes | Note 1.2% due 2018
Debt Instrument [Line Items]
Long-term Debt, gross	$ 400	400
Interest rate, stated percentage	1.20%
Senior Notes | Note 4.375% due 2019
Debt Instrument [Line Items]
Long-term Debt, gross	$ 400	400
Interest rate, stated percentage	4.375%
Senior Notes | Note 3.0% due 2022
Debt Instrument [Line Items]
Long-term Debt, gross	$ 400	400
Interest rate, stated percentage	3.00%
Senior Notes | Note 2.75% due 2023
Debt Instrument [Line Items]
Long-term Debt, gross	$ 400	400
Interest rate, stated percentage	2.75%
Senior Notes | Note 3.35% due 2024
Debt Instrument [Line Items]
Long-term Debt, gross	$ 400	400
Interest rate, stated percentage	3.35%
Bonds | Variable-rate industrial revenue bonds .87% due 2035 to 2050
Debt Instrument [Line Items]
Long-term Debt, gross	$ 631.9	769.9
Interest rate, weighted average	0.87%
Bonds | Other .89% due 2018 to 2019
Debt Instrument [Line Items]
Long-term Debt, gross	$ 10.9	25.7
Interest rate, weighted average	0.89%
Bonds | Eurobonds 4.625% due 2017
Debt Instrument [Line Items]
Long-term Debt, gross	$ 0	337
Interest rate, stated percentage	4.625%
Bonds | Eurobonds 2.0% due 2020
Debt Instrument [Line Items]
Long-term Debt, gross	$ 354.4	337
Interest rate, stated percentage	2.00%
Bonds | Eurobonds 1.0% due 2025
Debt Instrument [Line Items]
Long-term Debt, gross	$ 354.4	337
Interest rate, stated percentage	1.00%
Bonds | Eurobonds .375% due 2021
Debt Instrument [Line Items]
Long-term Debt, gross	$ 413.5	393.2
Interest rate, stated percentage	0.375%
Bonds | Other Foreign 4.3% due 2018 to 2022
Debt Instrument [Line Items]
Long-term Debt, gross	$ 25.8	52.9
Interest rate, stated percentage	4.30%
Capital Lease Obligations | United States 5.0% due 2018
Debt Instrument [Line Items]
Long-term Debt, gross	$ 0.2	0.5
Interest rate, stated percentage	5.00%
Capital Lease Obligations | Foreign 10.7% due 2018 to 2036
Debt Instrument [Line Items]
Long-term Debt, gross	$ 10.6	$ 9.7
Interest rate, stated percentage	10.70%

Debt (Maturities of Long-term D

Debt (Maturities of Long-term Debt) (Details) - USD ($) $ in Millions	Sep. 30, 2017	Sep. 30, 2016
Debt Disclosure [Abstract]
2,018	$ 416.4
2,019	409
2,020	356.1
2,021	433.3
2,022	401
Thereafter	1,821.5
Total	$ 3,837.3	$ 4,298.5

Retirement Benefits (Narrative)

Retirement Benefits (Narrative) (Details) - USD ($) $ in Millions		Jan. 03, 2017	Oct. 01, 2016	Sep. 30, 2017		Jun. 30, 2017	[1]	Mar. 31, 2017	[1]	Dec. 31, 2016	[1]	Sep. 30, 2016		Jun. 30, 2016	[1]	Mar. 31, 2016	[1]	Dec. 31, 2015	[1]	Sep. 30, 2017		Sep. 30, 2016		Sep. 30, 2015
Defined Benefit Plan Disclosure [Line Items]
Pension settlement loss				$ 0.9	[1]	$ 5.5		$ 4.1		$ 0		$ 2.1	[1]	$ 1		$ 2		$ 0		$ 10.5	[1]	$ 5.1	[1]	$ 19.3
Shares of common stock in ESOP				2,483,225																2,483,225
Defined contribution plan, cost recognized																				$ 33.7		34.6		36.8
Materials Technologies
Defined Benefit Plan Disclosure [Line Items]
Periodic benefit costs including settlement, curtailment, and special termination benefits																				6
Materials Technologies | Business Separation Costs
Defined Benefit Plan Disclosure [Line Items]
Periodic benefit costs including settlement, curtailment, and special termination benefits																				2.5
Materials Technologies | Discontinued Operations
Defined Benefit Plan Disclosure [Line Items]
Periodic benefit costs including settlement, curtailment, and special termination benefits																				$ 3.5
U.S.
Defined Benefit Plan Disclosure [Line Items]
Expected return on plan assets																				8.00%
U.S. | Equity Securities
Defined Benefit Plan Disclosure [Line Items]
Expected return on plan assets																				8.20%
U.S. | Debt Securities
Defined Benefit Plan Disclosure [Line Items]
Expected return on plan assets																				5.00%
U.S. | Real Estate/Other
Defined Benefit Plan Disclosure [Line Items]
Expected return on plan assets																				7.00%
International
Defined Benefit Plan Disclosure [Line Items]
Expected return on plan assets																				6.10%
U.K.
Defined Benefit Plan Disclosure [Line Items]
Expected return on plan assets																				6.60%
U.K. | Equity Securities
Defined Benefit Plan Disclosure [Line Items]
Expected return on plan assets																				7.30%
U.K. | Debt Securities
Defined Benefit Plan Disclosure [Line Items]
Expected return on plan assets																				3.50%
Defined Benefit Pension Plan
Defined Benefit Plan Disclosure [Line Items]
Pension settlement loss																				$ 10.5		5.1		19.3
Approximate average remaining service period																				9 years
ABO for all defined benefit pension plans				$ 4,842.8								4,954.9								$ 4,842.8		4,954.9
Company contributions																				64.1
Defined Benefit Pension Plan | Electronic Materials Division (EMD)
Defined Benefit Plan Disclosure [Line Items]
Decrease in underfunded status of pension plan due to transfer of pension assets and obligations			$ 24
Decrease in accumulated other comprehensive loss, net of tax, due to transfer pension unrecognized losses			5
Defined Benefit Pension Plan | Performance Materials Division (PMD)
Defined Benefit Plan Disclosure [Line Items]
Decrease in underfunded status of pension plan due to transfer of pension assets and obligations		$ 7
Defined Benefit Pension Plan | Minimum
Defined Benefit Plan Disclosure [Line Items]
Total expected contributions for next fiscal year				50																50
Defined Benefit Pension Plan | Maximum
Defined Benefit Plan Disclosure [Line Items]
Total expected contributions for next fiscal year				70																70
Defined Benefit Pension Plan | Unfunded Plan
Defined Benefit Plan Disclosure [Line Items]
ABO for plans with obligation in excess plan assets				99																99
PBO for plans with obligation in excess plan assets				107.8																107.8
Defined Benefit Pension Plan | U.S.
Defined Benefit Plan Disclosure [Line Items]
Pension settlement loss																				10.5		5.1		$ 18.9
Component of benefits paid related to lump sum payment to terminated participants																						52.9
ABO for plans with obligation in excess plan assets				2,951								3,242.5								2,951		3,242.5
PBO for plans with obligation in excess plan assets				$ 3,116.7								$ 3,477.7								$ 3,116.7		$ 3,477.7
Expected return on plan assets																				8.00%		8.00%		8.30%
Company contributions																				$ 27.2		$ 13.9
Net periodic postretirement cost discount rate	[2]																			3.50%		4.30%		4.30%
Accumulated postretirement benefit obligation discount rate				3.80%								3.50%								3.80%		3.50%
Net actuarial loss				$ 980.5								$ 1,273.6								$ 980.5		$ 1,273.6
Actuarial loss estimated				88.5																88.5
Periodic benefit costs including settlement, curtailment, and special termination benefits																				37.4		40.1		$ 79
Defined Benefit Pension Plan | International
Defined Benefit Plan Disclosure [Line Items]
Pension settlement loss																				1.7		1.3		$ 2.3
ABO for plans with obligation in excess plan assets				365.6								1,673.6								365.6		1,673.6
PBO for plans with obligation in excess plan assets				$ 465.7								$ 1,849.6								$ 465.7		$ 1,849.6
Expected return on plan assets																				6.10%		6.30%		6.10%
Company contributions																				$ 42.2		$ 65.4
Net periodic postretirement cost discount rate	[2]																			2.00%		3.30%		3.60%
Accumulated postretirement benefit obligation discount rate				2.40%								2.00%								2.40%		2.00%
Net actuarial loss				$ 551.9								$ 769.6								$ 551.9		$ 769.6
Actuarial loss estimated				$ 39.9																39.9
Periodic benefit costs including settlement, curtailment, and special termination benefits																				$ 39.4		$ 28		$ 56.6
Defined Benefit Pension Plan | International | Electronic Materials Division (EMD)
Defined Benefit Plan Disclosure [Line Items]
Decrease in underfunded status of pension plan due to transfer of pension assets and obligations			$ 3
Other Postretirement Benefits Plan
Defined Benefit Plan Disclosure [Line Items]
Net periodic postretirement cost discount rate																				1.90%		2.40%		2.60%
Accumulated postretirement benefit obligation discount rate				2.40%								1.90%								2.40%		1.90%
Net actuarial loss				$ 7.8								$ 18.7								$ 7.8		$ 18.7
Actuarial loss estimated				$ 0.3																0.3
Periodic benefit costs including settlement, curtailment, and special termination benefits																				$ 2.9		$ 4.9		$ 5.8
[1]	For additional information, see Note 16, Retirement Benefits.
[2]	Effective in 2016, the Company began to measure the service cost and interest cost components of pension expense by applying spot rates along the yield curve to the relevant projected cash flows, as we believe this provides a better measurement of these costs. The Company accounted for this in 2016 as a change in accounting estimate and, accordingly, accounted for it on a prospective basis. This change did not affect the measurement of the total benefit obligation. The 2017 discount rates used to measure the service cost and interest cost of our U.S. pension plans were 3.6% and 3.0%, respectively. The rates used to measure the service cost and interest cost of our major International pension plans were 2.1% and 1.8%, respectively. The previous method would have used a single discount rate for both service and interest costs.

Retirement Benefits (Schedule o

Retirement Benefits (Schedule of Net Periodic Benefit Cost) (Details) - USD ($) $ in Millions	3 Months Ended																12 Months Ended
	Sep. 30, 2017	[1]	Jun. 30, 2017	[1]	Mar. 31, 2017	[1]	Dec. 31, 2016	[1]	Sep. 30, 2016	[1]	Jun. 30, 2016	[1]	Mar. 31, 2016	[1]	Dec. 31, 2015	[1]	Sep. 30, 2017		Sep. 30, 2016		Sep. 30, 2015
Defined Benefit Plan Disclosure [Line Items]
Settlements	$ 0.9		$ 5.5		$ 4.1		$ 0		$ 2.1		$ 1		$ 2		$ 0		$ 10.5	[1]	$ 5.1	[1]	$ 19.3
Defined Benefit Pension Plan
Defined Benefit Plan Disclosure [Line Items]
Settlements																	10.5		5.1		19.3
Defined Benefit Pension Plan | U.S.
Defined Benefit Plan Disclosure [Line Items]
Service cost																	29		36.5		42.2
Interest cost																	107.5		110.7		124.7
Expected return on plan assets																	(207.7)		(202)		(202)
Net actuarial loss amortization																	88.7		85.3		78.9
Prior service cost amortization																	2.3		2.8		2.8
Settlements																	10.5		5.1		18.9
Curtailments																	4.3		0		5.3
Special termination benefits																	2.8		2		7.2
Other																	0		(0.3)		1
Net periodic benefit cost																	37.4		40.1		79
Defined Benefit Pension Plan | U.S. | Discontinued Operations
Defined Benefit Plan Disclosure [Line Items]
Net periodic benefit cost																	(0.7)		(7.9)		(12.9)
Defined Benefit Pension Plan | U.S. | Continuing Operations
Defined Benefit Plan Disclosure [Line Items]
Net periodic benefit cost																	36.7		32.2		66.1
Defined Benefit Pension Plan | International
Defined Benefit Plan Disclosure [Line Items]
Service cost																	25.9		24.3		31.3
Interest cost																	32.2		44.3		57.8
Expected return on plan assets																	(75.2)		(78.3)		(79.8)
Net actuarial loss amortization																	54.7		35.6		41.4
Prior service cost amortization																	(0.1)		(0.2)		0
Settlements																	1.7		1.3		2.3
Curtailments																	(1.3)		(1.1)		0
Special termination benefits																	0.4		0		1.5
Other																	1.1		2.1		2.1
Net periodic benefit cost																	39.4		28		56.6
Defined Benefit Pension Plan | International | Discontinued Operations
Defined Benefit Plan Disclosure [Line Items]
Net periodic benefit cost																	(4.1)		(4.4)		(7.7)
Defined Benefit Pension Plan | International | Continuing Operations
Defined Benefit Plan Disclosure [Line Items]
Net periodic benefit cost																	$ 35.3		$ 23.6		$ 48.9
[1]	For additional information, see Note 16, Retirement Benefits.

Retirement Benefits (Assumption

Retirement Benefits (Assumptions in Calculating Net Periodic Benefit Cost) (Details)		12 Months Ended
		Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2015
U.S.
Defined Benefit Plan Disclosure [Line Items]
Expected return on plan assets		8.00%
International
Defined Benefit Plan Disclosure [Line Items]
Expected return on plan assets		6.10%
Defined Benefit Pension Plan | U.S.
Defined Benefit Plan Disclosure [Line Items]
Discount rate	[1]	3.50%	4.30%	4.30%
Expected return on plan assets		8.00%	8.00%	8.30%
Rate of compensation increase		3.50%	3.50%	3.50%
Discount rate used to measure service cost		3.60%
Discount rate used to measure interest cost		3.00%
Defined Benefit Pension Plan | International
Defined Benefit Plan Disclosure [Line Items]
Discount rate	[1]	2.00%	3.30%	3.60%
Expected return on plan assets		6.10%	6.30%	6.10%
Rate of compensation increase		3.50%	3.50%	3.60%
Discount rate used to measure service cost		2.10%
Discount rate used to measure interest cost		1.80%
[1]	Effective in 2016, the Company began to measure the service cost and interest cost components of pension expense by applying spot rates along the yield curve to the relevant projected cash flows, as we believe this provides a better measurement of these costs. The Company accounted for this in 2016 as a change in accounting estimate and, accordingly, accounted for it on a prospective basis. This change did not affect the measurement of the total benefit obligation. The 2017 discount rates used to measure the service cost and interest cost of our U.S. pension plans were 3.6% and 3.0%, respectively. The rates used to measure the service cost and interest cost of our major International pension plans were 2.1% and 1.8%, respectively. The previous method would have used a single discount rate for both service and interest costs.

Retirement Benefits (Assumpt103

Retirement Benefits (Assumptions in Calculating Projected Benefit Obligation) (Details) - Defined Benefit Pension Plan	Sep. 30, 2017	Sep. 30, 2016
U.S.
Defined Benefit Plan Disclosure [Line Items]
Discount rate	3.80%	3.50%
Rate of compensation increase	3.50%	3.50%
International
Defined Benefit Plan Disclosure [Line Items]
Discount rate	2.40%	2.00%
Rate of compensation increase	3.60%	3.50%

Retirement Benefits (Change in

Retirement Benefits (Change in Projected Benefit Obligation) (Details) - Defined Benefit Pension Plan - USD ($) $ in Millions	12 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2015
U.S.
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Obligation at beginning of year	$ 3,477.7	$ 3,139.9
Service cost	29	36.5	$ 42.2
Interest cost	107.5	110.7	124.7
Amendments	1.9	1.2
Actuarial (gain) loss	(68)	380.2
Divestitures	0	0
Curtailments	(17.3)	(0.4)
Settlement (gain) loss	7	5.4
Special termination benefits	2.8	2
Participant contributions	0	0
Benefits paid	(182.9)	(197.4)
Other	0	(0.4)
Obligation at end of year	3,357.7	3,477.7	3,139.9
International
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Obligation at beginning of year	1,849.6	1,647.9
Service cost	25.9	24.3	31.3
Interest cost	32.2	44.3	57.8
Amendments	0	0
Actuarial (gain) loss	(132.4)	376.4
Divestitures	(34.1)	0
Curtailments	(4.2)	(1.2)
Settlement (gain) loss	0	(3.4)
Special termination benefits	0	0
Participant contributions	1.4	1.6
Benefits paid	(46.5)	(46.6)
Currency translation/other	57.6	(193.7)
Obligation at end of year	$ 1,749.5	$ 1,849.6	$ 1,647.9

Retirement Benefits (Change 105

Retirement Benefits (Change in Plan Assets) (Details) - Defined Benefit Pension Plan - USD ($) $ in Millions	12 Months Ended
	Sep. 30, 2017	Sep. 30, 2016
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Company contributions	$ 64.1
U.S.
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value at beginning of year	2,705.3	$ 2,613.6
Actual return on plan assets	319.6	275.2
Company contributions	27.2	13.9
Participant contributions	0	0
Divestitures	0	0
Benefits paid	(182.9)	(197.4)
Settlements	0	0
Currency translation/other	0	0
Fair value at end of year	2,869.2	2,705.3
Funded Status at End of Year	(488.5)	(772.4)
International
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value at beginning of year	1,411.1	1,302.8
Actual return on plan assets	87.9	273.2
Company contributions	42.2	65.4
Participant contributions	1.4	1.6
Divestitures	(3)	0
Benefits paid	(46.5)	(46.6)
Settlements	(5.3)	(3.4)
Currency translation/other	52.2	(181.9)
Fair value at end of year	1,540	1,411.1
Funded Status at End of Year	$ (209.5)	$ (438.5)

Retirement Benefits (Amounts Re

Retirement Benefits (Amounts Recognized on Balance Sheet) (Details) - USD ($) $ in Millions	Sep. 30, 2017	Sep. 30, 2016
Defined Benefit Plan Disclosure [Line Items]
Noncurrent assets	$ 18.4	$ 0
Accrued liabilities	(22.6)	(35.5)
Defined Benefit Pension Plan | U.S.
Defined Benefit Plan Disclosure [Line Items]
Noncurrent assets	5.3	0
Accrued liabilities	(12.6)	(24.1)
Noncurrent liabilities	(481.2)	(748.3)
Net Amount Recognized	(488.5)	(772.4)
Defined Benefit Pension Plan | International
Defined Benefit Plan Disclosure [Line Items]
Noncurrent assets	13.1	0
Accrued liabilities	0	0
Noncurrent liabilities	(222.6)	(438.5)
Net Amount Recognized	$ (209.5)	$ (438.5)

Retirement Benefits (Changes Re

Retirement Benefits (Changes Recognized in Other Comprehensive Income on Pretax Basis) (Details) - Defined Benefit Pension Plan - USD ($) $ in Millions	12 Months Ended
	Sep. 30, 2017	Sep. 30, 2016
U.S.
Defined Benefit Plan Disclosure [Line Items]
Net actuarial (gain) loss arising during the period	$ (189.8)	$ 311.8
Amortization of net actuarial loss	(103.3)	(90.4)
Prior service cost (credit) arising during the period	1.9	1.2
Amortization of prior service cost	(2.3)	(2.8)
Total	(293.5)	219.8
International
Defined Benefit Plan Disclosure [Line Items]
Net actuarial (gain) loss arising during the period	(162)	172.1
Amortization of net actuarial loss	(55.7)	(36.5)
Prior service cost (credit) arising during the period	0	(0.1)
Amortization of prior service cost	0.1	0.2
Total	$ (217.6)	$ 135.7

Retirement Benefits (Components

Retirement Benefits (Components Recognized in Accumulated Other Comprehensive Income on Pretax Basis) (Details) - Defined Benefit Pension Plan - USD ($) $ in Millions	Sep. 30, 2017	Sep. 30, 2016
U.S.
Defined Benefit Plan Disclosure [Line Items]
Net actuarial loss	$ 980.5	$ 1,273.6
Prior service cost (credit)	8.1	8.5
Net transition liability	0	0
Total	988.6	1,282.1
International
Defined Benefit Plan Disclosure [Line Items]
Net actuarial loss	551.9	769.6
Prior service cost (credit)	(1.8)	(1.9)
Net transition liability	0.4	0.4
Total	$ 550.5	$ 768.1

Retirement Benefits (Amount of

Retirement Benefits (Amount of Accumulated Other Comprehensive Income Expected to be Recognized in Next Fiscal Year) (Details) - Defined Benefit Pension Plan $ in Millions	Sep. 30, 2017USD ($)
U.S.
Defined Benefit Plan Disclosure [Line Items]
Net actuarial loss	$ 88.5
Prior service cost (credit)	1.5
International
Defined Benefit Plan Disclosure [Line Items]
Net actuarial loss	39.9
Prior service cost (credit)	$ (0.1)

Retirement Benefits (Benefit Li

Retirement Benefits (Benefit Liability Exceeds Value of Plan Assets) (Details) - Defined Benefit Pension Plan - USD ($) $ in Millions	Sep. 30, 2017	Sep. 30, 2016
U.S.
Pension Plans with PBO in Excess of Plan Assets:
PBO	$ 3,116.7	$ 3,477.7
Fair value of Plan assets	2,623	2,705.3
Pension Plans with ABO in Excess of Plan Assets:
ABO	2,951	3,242.5
Fair value of plan assets	2,623	2,705.3
International
Pension Plans with PBO in Excess of Plan Assets:
PBO	465.7	1,849.6
Fair value of Plan assets	243.1	1,411.1
Pension Plans with ABO in Excess of Plan Assets:
ABO	365.6	1,673.6
Fair value of plan assets	$ 197.1	$ 1,370.1

Retirement Benefits (Plan Asset

Retirement Benefits (Plan Assets Target Allocation) (Details) - Defined Benefit Pension Plan	Sep. 30, 2017	Sep. 30, 2016
U.S.
Defined Benefit Plan Disclosure [Line Items]
Actual allocation, percentage	100.00%	100.00%
U.S. | Equity Securities
Defined Benefit Plan Disclosure [Line Items]
Actual allocation, percentage	58.00%	65.00%
U.S. | Debt Securities
Defined Benefit Plan Disclosure [Line Items]
Actual allocation, percentage	34.00%	28.00%
U.S. | Real Estate/Other
Defined Benefit Plan Disclosure [Line Items]
Actual allocation, percentage	7.00%	7.00%
U.S. | Cash
Defined Benefit Plan Disclosure [Line Items]
Actual allocation, percentage	1.00%	0.00%
U.S. | Minimum | Equity Securities
Defined Benefit Plan Disclosure [Line Items]
Target allocation, percentage	46.00%
U.S. | Minimum | Debt Securities
Defined Benefit Plan Disclosure [Line Items]
Target allocation, percentage	32.00%
U.S. | Minimum | Real Estate/Other
Defined Benefit Plan Disclosure [Line Items]
Target allocation, percentage	0.00%
U.S. | Minimum | Cash
Defined Benefit Plan Disclosure [Line Items]
Target allocation, percentage	0.00%
U.S. | Maximum | Equity Securities
Defined Benefit Plan Disclosure [Line Items]
Target allocation, percentage	66.00%
U.S. | Maximum | Debt Securities
Defined Benefit Plan Disclosure [Line Items]
Target allocation, percentage	42.00%
U.S. | Maximum | Real Estate/Other
Defined Benefit Plan Disclosure [Line Items]
Target allocation, percentage	10.00%
U.S. | Maximum | Cash
Defined Benefit Plan Disclosure [Line Items]
Target allocation, percentage	0.00%
International
Defined Benefit Plan Disclosure [Line Items]
Actual allocation, percentage	100.00%	100.00%
International | Equity Securities
Defined Benefit Plan Disclosure [Line Items]
Actual allocation, percentage	53.00%	60.00%
International | Debt Securities
Defined Benefit Plan Disclosure [Line Items]
Actual allocation, percentage	46.00%	38.00%
International | Real Estate/Other
Defined Benefit Plan Disclosure [Line Items]
Actual allocation, percentage	1.00%	1.00%
International | Cash
Defined Benefit Plan Disclosure [Line Items]
Actual allocation, percentage	0.00%	1.00%
International | Minimum | Equity Securities
Defined Benefit Plan Disclosure [Line Items]
Target allocation, percentage	46.00%
International | Minimum | Debt Securities
Defined Benefit Plan Disclosure [Line Items]
Target allocation, percentage	41.00%
International | Minimum | Real Estate/Other
Defined Benefit Plan Disclosure [Line Items]
Target allocation, percentage	0.00%
International | Minimum | Cash
Defined Benefit Plan Disclosure [Line Items]
Target allocation, percentage	0.00%
International | Maximum | Equity Securities
Defined Benefit Plan Disclosure [Line Items]
Target allocation, percentage	57.00%
International | Maximum | Debt Securities
Defined Benefit Plan Disclosure [Line Items]
Target allocation, percentage	53.00%
International | Maximum | Real Estate/Other
Defined Benefit Plan Disclosure [Line Items]
Target allocation, percentage	2.00%
International | Maximum | Cash
Defined Benefit Plan Disclosure [Line Items]
Target allocation, percentage	0.00%

Retirement Benefits (Pension Pl

Retirement Benefits (Pension Plan Assets at Fair Value by Asset Class) (Details) - Defined Benefit Pension Plan - USD ($) $ in Millions	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2015
Level 3
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	$ 257	$ 245.2	$ 226.1
Level 3 | Real Estate Pooled Funds
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	207.8	192.1	174.2
Level 3 | Other Pooled Funds
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	7.8	7.3	6.6
Level 3 | Insurance Contracts
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	41.4	45.8	45.3
U.S.
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	2,869.2	2,705.3	2,613.6
U.S. | Cash and Cash Equivalents
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	13.6	12.7
U.S. | Equity Securities
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	598.6	637
U.S. | Equity Mutual Funds
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	276.5	300.2
U.S. | Equity Pooled Funds
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	787	815.5
U.S. | Debt Securities
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	985.7	747.8
U.S. | Real Estate Pooled Funds
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	207.8	192.1
U.S. | Level 1
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	888.7	949.9
U.S. | Level 1 | Cash and Cash Equivalents
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	13.6	12.7
U.S. | Level 1 | Equity Securities
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	598.6	637
U.S. | Level 1 | Equity Mutual Funds
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	276.5	300.2
U.S. | Level 1 | Equity Pooled Funds
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
U.S. | Level 1 | Debt Securities
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
U.S. | Level 1 | Real Estate Pooled Funds
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
U.S. | Level 2
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	1,772.7	1,563.3
U.S. | Level 2 | Cash and Cash Equivalents
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
U.S. | Level 2 | Equity Securities
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
U.S. | Level 2 | Equity Mutual Funds
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
U.S. | Level 2 | Equity Pooled Funds
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	787	815.5
U.S. | Level 2 | Debt Securities
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	985.7	747.8
U.S. | Level 2 | Real Estate Pooled Funds
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
U.S. | Level 3
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	207.8	192.1
U.S. | Level 3 | Cash and Cash Equivalents
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
U.S. | Level 3 | Equity Securities
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
U.S. | Level 3 | Equity Mutual Funds
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
U.S. | Level 3 | Equity Pooled Funds
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
U.S. | Level 3 | Debt Securities
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
U.S. | Level 3 | Real Estate Pooled Funds
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	207.8	192.1
International
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	1,540	1,411.1	$ 1,302.8
International | Cash and Cash Equivalents
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	7.3	6.6
International | Equity Pooled Funds
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	821.4	854.8
International | Fixed Income Funds
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	651.3	486.9
International | Other Pooled Funds
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	18.6	17
International | Insurance Contracts
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	41.4	45.8
International | Level 1
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	7.3	6.6
International | Level 1 | Cash and Cash Equivalents
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	7.3	6.6
International | Level 1 | Equity Pooled Funds
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
International | Level 1 | Fixed Income Funds
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
International | Level 1 | Other Pooled Funds
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
International | Level 1 | Insurance Contracts
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
International | Level 2
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	1,483.5	1,351.4
International | Level 2 | Cash and Cash Equivalents
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
International | Level 2 | Equity Pooled Funds
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	821.4	854.8
International | Level 2 | Fixed Income Funds
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	651.3	486.9
International | Level 2 | Other Pooled Funds
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	10.8	9.7
International | Level 2 | Insurance Contracts
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
International | Level 3
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	49.2	53.1
International | Level 3 | Cash and Cash Equivalents
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
International | Level 3 | Equity Pooled Funds
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
International | Level 3 | Fixed Income Funds
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
International | Level 3 | Other Pooled Funds
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	7.8	7.3
International | Level 3 | Insurance Contracts
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	$ 41.4	$ 45.8

Retirement Benefits (Summary of

Retirement Benefits (Summary of Changes in Pension Plan Assets Fair Value Classified as Level 3) (Details) - Defined Benefit Pension Plan - Level 3 - USD ($) $ in Millions	12 Months Ended
	Sep. 30, 2017	Sep. 30, 2016
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value at beginning of year	$ 245.2	$ 226.1
Actual return on plan assets:
Assets held at end of year	15.9	21.2
Assets sold during the period	0.3	0.3
Purchases, sales, and settlements, net	(4.4)	(2.4)
Fair value at end of year	257	245.2
Real Estate Pooled Funds
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value at beginning of year	192.1	174.2
Actual return on plan assets:
Assets held at end of year	15.7	17.9
Assets sold during the period	0	0
Purchases, sales, and settlements, net	0	0
Fair value at end of year	207.8	192.1
Other Pooled Funds
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value at beginning of year	7.3	6.6
Actual return on plan assets:
Assets held at end of year	1.2	0.1
Assets sold during the period	0.3	0.3
Purchases, sales, and settlements, net	(1)	0.3
Fair value at end of year	7.8	7.3
Insurance Contracts
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value at beginning of year	45.8	45.3
Actual return on plan assets:
Assets held at end of year	(1)	3.2
Assets sold during the period	0	0
Purchases, sales, and settlements, net	(3.4)	(2.7)
Fair value at end of year	$ 41.4	$ 45.8

Retirement Benefits (Projected

Retirement Benefits (Projected Benefit Payments) (Details) - Defined Benefit Pension Plan $ in Millions	Sep. 30, 2017USD ($)
U.S.
Defined Benefit Plan Disclosure [Line Items]
2,018	$ 158.5
2,019	163.4
2,020	167.3
2,021	171.4
2,022	177.2
2023-2027	938.5
International
Defined Benefit Plan Disclosure [Line Items]
2,018	50.9
2,019	53.4
2,020	53.8
2,021	56.8
2,022	59.3
2023-2027	$ 333.3

Retirement Benefits (Other Post

Retirement Benefits (Other Postretirement Benefit Plan Components) (Details) - Other Postretirement Benefits Plan - USD ($) $ in Millions	12 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2015
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Service cost	$ 1.1	$ 2.2	$ 2.8
Interest cost	1.6	2	2.2
Net actuarial loss amortization	0.2	0.7	0.8
Net periodic benefit cost	2.9	4.9	5.8
Discontinued Operations
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Net periodic benefit cost	0	(0.4)	(0.7)
Continuing Operations
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Net periodic benefit cost	$ 2.9	$ 4.5	$ 5.1

Retirement Benefits (Other P116

Retirement Benefits (Other Postretirement Benefit Plan Accumulated Benefit Obligation) (Details) - Other Postretirement Benefits Plan - USD ($) $ in Millions	12 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2015
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Obligation at beginning of year	$ 86.3	$ 86.9
Service cost	1.1	2.2	$ 2.8
Interest cost	1.6	2	2.2
Actuarial (gain) loss	(7.2)	7.5
Curtailment gain	(3.5)	0
Benefits paid	(11.3)	(12.3)
Obligation at end of year	$ 67	$ 86.3	$ 86.9

Retirement Benefits (Other P117

Retirement Benefits (Other Postretirement Benefit Plans Amounts Recognized on Balance Sheet) (Details) - USD ($) $ in Millions	Sep. 30, 2017	Sep. 30, 2016
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Accrued liabilities	$ 22.6	$ 35.5
Other Postretirement Benefits Plan
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Accrued liabilities	10	11.4
Noncurrent liabilities	$ 57	$ 74.9

Retirement Benefits (Other P118

Retirement Benefits (Other Postretirement Benefit Plans Changes Recognized in Other Comprehensive Income on Pretax Basis) (Details) - Other Postretirement Benefits Plan - USD ($) $ in Millions	12 Months Ended
	Sep. 30, 2017	Sep. 30, 2016
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Net actuarial (gain) loss arising during the period	$ (10.7)	$ 7.5
Amortization of net actuarial loss	(0.2)	(0.7)
Total	$ (10.9)	$ 6.8

Retirement Benefits (Other P119

Retirement Benefits (Other Postretirement Benefit Plans Projected Benefit Payments) (Details) - Other Postretirement Benefits Plan $ in Millions	Sep. 30, 2017USD ($)
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
2,018	$ 10.1
2,019	9.5
2,020	9
2,021	8.4
2,022	7.7
2023-2027	$ 24.2

Commitments and Contingencie120

Commitments and Contingencies (Litigation and Environmental Narrative) (Details) BRL in Millions	1 Months Ended	12 Months Ended
	Sep. 30, 2010BRL	Sep. 30, 2017USD ($)site	Sep. 30, 2017BRLsite	Sep. 30, 2016USD ($)
Alleged Anticompete Litigation
Loss Contingencies [Line Items]
Civil fines imposed	BRL 179.2	$ 57,000,000
Provision for litigation		0
Maximum of loss contingency range subject to interest		$ 57,000,000	BRL 179.2
Environmental
Loss Contingencies [Line Items]
Approximate number of sites on which settlement has not been reached | site		32	32
Accrual for environmental loss contingencies		$ 83,600,000		$ 81,400,000
Accrual for environmental loss contingencies, maximum payout period		30 years
Environmental | Minimum
Loss Contingencies [Line Items]
Estimate of possible exposure from environment loss contingencies		$ 83,000,000
Environmental | Maximum
Loss Contingencies [Line Items]
Estimate of possible exposure from environment loss contingencies		$ 97,000,000

Commitments and Contingencie121

Commitments and Contingencies (Pace, Piedmont, Pasadena Narrative) (Details) - USD ($)	12 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2012	Sep. 30, 2008	Sep. 30, 2006
Loss Contingencies [Line Items]
Pretax environmental expense	$ 11,400,000	$ 12,200,000	$ 11,800,000
Pace, Florida
Loss Contingencies [Line Items]
Accrual for environmental loss contingencies	28,900,000					$ 42,000,000
Change in estimated exposure	0
Pace, Florida | Discontinued Operations
Loss Contingencies [Line Items]
Pretax environmental expense						42,000,000
Pace, Florida | Minimum
Loss Contingencies [Line Items]
Estimate of possible exposure from environment loss contingencies						42,000,000
Pace, Florida | Maximum
Loss Contingencies [Line Items]
Estimate of possible exposure from environment loss contingencies						$ 52,000,000
Piedmont, South Carolina
Loss Contingencies [Line Items]
Accrual for environmental loss contingencies	16,700,000				$ 24,000,000
Piedmont, South Carolina | Discontinued Operations
Loss Contingencies [Line Items]
Pretax environmental expense					$ 24,000,000
Pasadena, Texas
Loss Contingencies [Line Items]
Accrual for environmental loss contingencies	$ 12,100,000
Total anticipated exposure				$ 13,000,000

Commitments and Contingencie122

Commitments and Contingencies (Asset Retirement Obligations) (Details) - USD ($) $ in Millions	12 Months Ended
	Sep. 30, 2017	Sep. 30, 2016
Asset Retirement Obligation [Roll Forward]
Asset retirement obligations, beginning of period	$ 119.9	$ 109.4
Additional accruals	22.7	10.4
Liabilities settled	(4.1)	(4.4)
Accretion expense	5.8	5.4
Currency translation adjustment	0.4	(0.9)
Asset retirement obligations, end of period	$ 144.7	$ 119.9

Commitments and Contingencie123

Commitments and Contingencies (Guarantees and Other Narrative) (Details) £ in Millions, $ in Millions	Sep. 30, 2017USD ($)	Sep. 30, 2017GBP (£)	Sep. 30, 2016USD ($)	Apr. 30, 2015
Guarantor Obligations [Line Items]
Obligation for future contribution to equity affiliate	$ 94.4		$ 94.4
Equity contributions or payments required	0
Unrecorded Unconditional Purchase Obligation [Line Items]
Unconditional purchase obligation	6,533
Purchase obligations in 2018	822
Jazan Gas Projects Company
Guarantor Obligations [Line Items]
Obligation for future contribution to equity affiliate	94.4		$ 94.4
Jazan Gas Projects Company | Financial Guarantee
Guarantor Obligations [Line Items]
Percentage guaranteed share of loan				25.00%
Maximum potential payment under guarantees	100
Jazan Gas Projects Company | Performance Guarantee
Guarantor Obligations [Line Items]
Maximum potential payment under guarantees	262
Helium Purchases
Unrecorded Unconditional Purchase Obligation [Line Items]
Unconditional purchase obligation	5,600
HyCO Feedstock Supply
Unrecorded Unconditional Purchase Obligation [Line Items]
Unconditional purchase obligation	280
Purchase Commitments for Plant and Equipment
Unrecorded Unconditional Purchase Obligation [Line Items]
Purchase obligations in 2018	300
Jazan Gas Projects Company
Unrecorded Unconditional Purchase Obligation [Line Items]
Purchase obligations in 2018	$ 180
Trinidad Facility | Performance Guarantee
Guarantor Obligations [Line Items]
Percentage guaranteed share of loan	50.00%	50.00%
Maximum potential payment under guarantees	$ 28
U.K. and Ireland Homecare Business | Performance Guarantee
Guarantor Obligations [Line Items]
Maximum potential payment under guarantees	$ 25	£ 20

Commitments and Contingencie124

Commitments and Contingencies (Purchase Obligations) (Details) $ in Millions	Sep. 30, 2017USD ($)
Commitments and Contingencies Disclosure [Abstract]
2,018	$ 822
2,019	234
2,020	275
2,021	309
2,022	285
Thereafter	4,608
Total	$ 6,533

Capital Stock (Common Stock Nar

Capital Stock (Common Stock Narrative) (Details) - USD ($)	12 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2014	Sep. 15, 2011
Equity [Abstract]
Common stock, authorized shares	300,000,000
Common stock, par value (in dollars per share)	$ 1	$ 1
Common stock, shares issued	249,455,584	249,455,584
Common stock, shares outstanding	218,346,074	217,350,825	215,359,113	213,538,144
Share repurchase program authorized amount					$ 1,000,000,000
Shares repurchased during period (shares)	0
Share repurchase authorization remaining amount	$ 485,300,000

Capital Stock (Changes in Commo

Capital Stock (Changes in Common Shares) (Details) - shares	12 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2015
Changes in Common Shares [Roll Forward]
Balance, beginning of year (shares)	217,350,825	215,359,113	213,538,144
Issuance of treasury shares for stock option and award plans (shares)	995,249	1,991,712	1,820,969
Balance, end of year (shares)	218,346,074	217,350,825	215,359,113

Capital Stock (Preferred Stock

Capital Stock (Preferred Stock Narrative) (Details) - $ / shares	Sep. 30, 2017	Sep. 30, 2016
Class of Stock [Line Items]
Preferred stock, shares authorized	25,000,000
Perferred stock, par value (in dollars per share)	$ 1
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Series A Junior Participating Preferred Stock
Class of Stock [Line Items]
Preferred stock, shares authorized	2,500,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0

Share-Based Compensation (Narra

Share-Based Compensation (Narrative) (Details) $ / shares in Units, $ in Millions	12 Months Ended
	Sep. 30, 2017USD ($)$ / sharesshares	Sep. 30, 2016USD ($)$ / sharesshares	Sep. 30, 2015USD ($)$ / shares	Oct. 03, 2016$ / shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares available for future grant | shares	4,922,382
Closing stock price (in dollars per share) | $ / shares	$ 151.22	$ 150.35		$ 140.38
Conversion ratio for separation adjustments	1.071
Cash received from option exercises	$ 68.4	$ 141.3	$ 121.3
Deferred Stock Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of units/shares granted | shares	283,000
Weighted-average grant date fair value (in dollars per share) | $ / shares	$ 148.89
Cash payments made for deferred stock units	$ 2.1	2.9	9.6
Unrecognized compensation costs	$ 39
Unrecognized compensation costs, period for recognition, years	2 years
Fair value of deferred stock units paid	$ 36.6	$ 41.6	$ 35.5
Deferred Stock Units | Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting or deferral Period	2 years
Deferred Stock Units | Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting or deferral Period	5 years
Director Deferred Stock Units | Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Period after service in which to elect payment	10 years
Market-Based Deferred Stock Unit
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting or deferral Period	3 years
Number of units/shares granted | shares	117,692	130,167
Weighted-average grant date fair value (in dollars per share) | $ / shares	$ 156.87	$ 135.49
Time-Based Deferred Stock Unit
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of units/shares granted | shares	165,120.792160577
Weighted-average grant date fair value (in dollars per share) | $ / shares	$ 143.75
Stock Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting or deferral Period	3 years
Unrecognized compensation costs	$ 0.1
Unrecognized compensation costs, period for recognition, years	2 months
Exercisable period from grant date	10 years
Weighted-average grant date fair value of stock option (in dollars per share) | $ / shares			$ 37.19
Intrinsic value of stock options exercised	$ 57.3	$ 115.3	$ 115.5
Cash received from option exercises	68.4
Tax benefit realized from stock option exericses	19.9
Excess tax benefit	13.9
Restricted Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation costs	$ 0.4
Unrecognized compensation costs, period for recognition, years	1 year 5 months
Fair value of vested restricted stock	$ 4.1	$ 4.3	$ 1.4
Restricted Stock | Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting or deferral Period	1 year
Restricted Stock | Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting or deferral Period	4 years

Share-Based Compensation (Compe

Share-Based Compensation (Compensation Cost Recognized in Income Statement) (Details) - USD ($) $ in Millions	12 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2015
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Before-Tax Share-Based Compensation	$ 40.7	$ 37.6	$ 45.7
Discontinued Operations
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Before-Tax Share-Based Compensation	0.8	6.6	6.2
Continuing Operations
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Before-Tax Share-Based Compensation	39.9	31	39.5
Income Tax Benefit	(14)	(10.8)	(13.8)
After-Tax Share-Based Compensation	$ 25.9	$ 20.2	$ 25.7

Share-Based Compensation (Total

Share-Based Compensation (Total Before-Tax Share-Based Compensation Cost by Type of Program) (Details) - USD ($) $ in Millions	12 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2015
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Before-Tax Share-Based Compensation	$ 40.7	$ 37.6	$ 45.7
Deferred Stock Units
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Before-Tax Share-Based Compensation	34.5	29.9	28.8
Stock Options
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Before-Tax Share-Based Compensation	1.4	4.2	12.6
Restricted Stock
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Before-Tax Share-Based Compensation	$ 4.8	$ 3.5	$ 4.3

Share-Based Compensation (Marke

Share-Based Compensation (Market-Based Deferred Stock Unit Valuation Assumptions)(Details) - Market-Based Deferred Stock Unit	12 Months Ended
	Sep. 30, 2017	Sep. 30, 2016
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected volatility	20.60%	20.50%
Risk-free interest rate	1.40%	1.20%
Expected dividend yield	2.50%	2.20%

Share-Based Compensation (Summa

Share-Based Compensation (Summary of Deferred Stock Units Activity) (Details) - Deferred Stock Units shares in Thousands	12 Months Ended
	Sep. 30, 2017$ / sharesshares
Shares
Outstanding, beginning (shares) | shares	1,001
Equitable adjustment upon separation (shares) | shares	65
Surrender upon separation (shares) | shares	(89)
Granted (shares) | shares	283
Paid out (shares) | shares	(235)
Forfeited/adjustments (shares) | shares	(50)
Outstanding, ending (shares) | shares	975
Weighted Average Grant Date Fair Value
Outstanding, beginning (in dollars per share) | $ / shares	$ 119.44
Equitable adjustment upon separation (in dollars per share) | $ / shares	0
Surrender upon separation (in dollars per share) | $ / shares	132.88
Granted (in dollars per share) | $ / shares	148.89
Paid out (in dollars per share) | $ / shares	83.65
Forfeited/adjustments (in dollars per share) | $ / shares	121.99
Outstanding, ending (in dollars per share) | $ / shares	$ 127.29

Share-Based Compensation (Stock

Share-Based Compensation (Stock Option Valuation Assumptions) (Details) - Stock Options	12 Months Ended
	Sep. 30, 2015
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected volatility	30.30%
Expected dividend yield	2.60%
Expected life (in years)	7 years 6 months
Risk-free interest rate	2.20%

Share-Based Compensation (Su134

Share-Based Compensation (Summary of Stock Option Activity) (Details) shares in Thousands	12 Months Ended
	Sep. 30, 2017$ / sharesshares
Shares
Outstanding, beginning (shares) | shares	3,916
Equitable adjustment upon separation (shares) | shares	277	[1]
Surrender upon separation (shares) | shares	(102)	[2]
Exercised (shares) | shares	(886)
Forfeited (shares) | shares	(3)
Outstanding, ending (shares) | shares	3,202
Exercisable (shares) | shares	3,149
Weighted Average Exercise Price
Outstanding, beginning (in dollars per share) | $ / shares	$ 90.28
Equitable adjustment upon separation (in dollars per share) | $ / shares	0	[1]
Surrender upon separation (in dollars per share) | $ / shares	97.63	[2]
Exercised (in dollars per share) | $ / shares	80.76
Forfeited (in dollars per share) | $ / shares	105.28
Outstanding, ending (in dollars per share) | $ / shares	84.85
Exercisable (in dollars per share) | $ / shares	$ 84
[1]	Applicable deferred stock units have been adjusted by the conversion ratio of 1.071 to preserve the intrinsic value immediately before and after the spin-off of Versum.
[2]	In connection with the spin-off of Versum, EMD employees surrendered their outstanding Air Products equity awards, which were converted into Versum equity awards of equivalent fair value.

Share-Based Compensation (Su135

Share-Based Compensation (Summary of Stock Option Contract Term and Intrinsic Value) (Details) $ in Millions	12 Months Ended
	Sep. 30, 2017USD ($)
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Weighted Average Remaining Contractual Terms, Outstanding	4 years 3 months
Aggregated Intrinsic Value, Outstanding	$ 213
Weighted Average Remaining Contractual Terms, Exercisable	4 years 4 months
Aggregated Intrinsic Value, Exercisable	$ 212

Share-Based Compensation (Su136

Share-Based Compensation (Summary of Restricted Stock) (Details) - Restricted Stock shares in Thousands	12 Months Ended
	Sep. 30, 2017$ / sharesshares
Shares
Outstanding, beginning (shares) | shares	85
Vested (shares) | shares	(29)
Outstanding, ending (shares) | shares	56
Weighted Average Grant Date Fair Value
Outstanding, beginning (in dollars per share) | $ / shares	$ 128.16
Vested (in dollars per share) | $ / shares	113.50
Outstanding, ending (in dollars per share) | $ / shares	$ 135.74

Accumulated Other Comprehens137

Accumulated Other Comprehensive Loss (Rollforward) (Details) - USD ($) $ in Millions	12 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2015
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning balance	$ 7,213.4	$ 7,381.1	$ 7,521.4
Other comprehensive income (loss) before reclassifications	340.9	(311.5)	(1,012.8)
Amounts reclassified from AOCL	192.2	53.9	117.8
Total Other Comprehensive Income (Loss)	533.1	(257.6)	(895)
Spin-off of Versum	11.5
Amount attributable to noncontrolling interest	3.7	4.8	(11)
Ending Balance	10,185.5	7,213.4	7,381.1
Derivatives qualifying as hedges
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning balance	(65)	(42.9)	(28.5)
Other comprehensive income (loss) before reclassifications	(12.6)	13.7	(35)
Amounts reclassified from AOCL	24.2	(36)	20.8
Total Other Comprehensive Income (Loss)	11.6	(22.3)	(14.2)
Spin-off of Versum	0.2
Amount attributable to noncontrolling interest	(0.1)	(0.2)	0.2
Ending Balance	(53.1)	(65)	(42.9)
Foreign currency translation adjustments
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning balance	(949.3)	(956.5)	(268.7)
Other comprehensive income (loss) before reclassifications	101.9	9.9	(699.3)
Amounts reclassified from AOCL	57.3	2.7	0
Total Other Comprehensive Income (Loss)	159.2	12.6	(699.3)
Spin-off of Versum	6
Amount attributable to noncontrolling interest	3	5.4	(11.5)
Ending Balance	(787.1)	(949.3)	(956.5)
Pension and postretirement benefits
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning balance	(1,374)	(1,126.5)	(944.7)
Other comprehensive income (loss) before reclassifications	251.6	(335.1)	(278.5)
Amounts reclassified from AOCL	110.7	87.2	97
Total Other Comprehensive Income (Loss)	362.3	(247.9)	(181.5)
Spin-off of Versum	5.3
Amount attributable to noncontrolling interest	0.8	(0.4)	0.3
Ending Balance	(1,007.2)	(1,374)	(1,126.5)
AOCL attributable to Air Products
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning balance	(2,388.3)	(2,125.9)	(1,241.9)
Total Other Comprehensive Income (Loss)	529.4	(262.4)	(884)
Ending Balance	$ (1,847.4)	$ (2,388.3)	$ (2,125.9)

Accumulated Other Comprehens138

Accumulated Other Comprehensive Loss (Reclassification) (Details) - USD ($) $ in Millions		3 Months Ended																12 Months Ended
		Sep. 30, 2017		Jun. 30, 2017		Mar. 31, 2017		Dec. 31, 2016		Sep. 30, 2016		Jun. 30, 2016		Mar. 31, 2016		Dec. 31, 2015		Sep. 30, 2017		Sep. 30, 2016		Sep. 30, 2015
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Other income (expense), net																		$ (121)		$ (49.4)		$ (45.5)
Interest expense																		120.6		115.2		102.8
Business restructuring and cost reduction actions		$ 48.4	[1]	$ 42.7	[1]	$ 10.3	[1]	$ 50	[1]	$ 10.6	[1]	$ 13.2	[1]	$ 10.7	[1]	$ 0	[1]	151.4	[1]	34.5	[1]	180.1
Income (loss) from discontinued operations, net of tax																		(1,866)		460.5		(351.7)
Net income (loss) attributable to Air Products		$ (468.7)		$ (101.9)		$ (2,130)		$ (299.8)		$ (394)		$ (346.8)		$ 473.3		$ (363.6)		(3,000.4)		(631.1)		(1,277.9)
Reclassification out of Accumulated Other Comprehensive Income | (Gain) Loss on Cash Flow Hedges
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Sales/cost of sales																		18.3		0.2		0.6
Other income (expense), net																		5.1		(46.2)		16.9
Interest expense																		0.8		10		3.3
Net income (loss) attributable to Air Products																		24.2		(36)		20.8
Reclassification out of Accumulated Other Comprehensive Income | Currency Translation Adjustment
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Business restructuring and cost reduction actions	[2]																	8.2		0		0
Income (loss) from discontinued operations, net of tax	[3]																	49.1		2.7		0
Net income (loss) attributable to Air Products																		57.3		2.7		0
Reclassification out of Accumulated Other Comprehensive Income | Pension and Postretirement Benefits
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Net income (loss) attributable to Air Products	[4]																	$ 110.7		$ 87.2		$ 97
[1]	For additional information, see Note 5, Business Restructuring and Cost Reduction Actions.
[2]	The fiscal year 2017 impact relates to the planned sale of a non-industrial gas hardgoods business in the Industrial Gases – Americas segment recorded in the third quarter.
[3]	The fiscal year 2017 impact relates to the sale of PMD during the second quarter. The fiscal year 2016 impact primarily relates to the sale of an equity affiliate in the first quarter.
[4]	The components include items such as prior service cost amortization, actuarial loss amortization, and settlements and are reflected in net periodic benefit cost. Refer to Note 16, Retirement Benefits.

Earnings per Share (Schedule of

Earnings per Share (Schedule of Earnings per Share) (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended									12 Months Ended
	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017		Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2017		Sep. 30, 2016	Sep. 30, 2015
Earnings Per Share [Abstract]
Income from continuing operations	$ 474.2	$ 104.2	$ 304.4		$ 251.6	$ 289.4	$ 250.3	$ 278.9	$ 280.9	$ 1,134.4		$ 1,099.5	$ 933.3
Income (Loss) from discontinued operations	(5.5)	(2.3)	1,825.6	[1]	48.2	104.6	96.5	(752.2)	82.7	1,866	[1]	(468.4)	344.6
Net Income Attributable to Air Products	$ 468.7	$ 101.9	$ 2,130		$ 299.8	$ 394	$ 346.8	$ (473.3)	$ 363.6	$ 3,000.4		$ 631.1	$ 1,277.9
Weighted average common shares — Basic										218		216.4	214.9
Employee stock option and other award plans										1.8		1.9	2.4
Weighted average common shares — Diluted										219.8		218.3	217.3
Basic Earnings Per Common Share Attributable to Air Products
Income from continuing operations (in dollars per share)	$ 2.17	$ 0.48	$ 1.40		$ 1.16	$ 1.33	$ 1.16	$ 1.29	$ 1.30	$ 5.20		$ 5.08	$ 4.34
Income (Loss) from discontinued operations (in dollars per share)	(0.02)	(0.01)	8.38		0.22	0.48	0.44	(3.48)	0.38	8.56		(2.16)	1.61
Net Income Attributable to Air Products (in dollars per share)	2.15	0.47	9.78		1.38	1.81	1.60	(2.19)	1.68	13.76		2.92	5.95
Diluted Earnings Per Common Share Attributable to Air Products
Income from continuing operations (in dollars per share)	2.15	0.47	1.39		1.15	1.32	1.15	1.28	1.29	5.16		5.04	4.29
Income (Loss) from discontinued operations (in dollars per share)	(0.02)	(0.01)	8.31		0.22	0.48	0.44	(3.45)	0.38	8.49		(2.15)	1.59
Net Income Attributable to Air Products (in dollars per share)	$ 2.13	$ 0.46	$ 9.70		$ 1.37	$ 1.80	$ 1.59	$ (2.17)	$ 1.67	$ 13.65		$ 2.89	$ 5.88
[1]	Includes the after-tax gain on the sale of PMD. For additional information, see Note 3, Discontinued Operations.

Earnings per Share (Narrative)

Earnings per Share (Narrative) (Details) - shares	12 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2015
Earnings Per Share [Abstract]
Antidilutive options excluded from computation of diluted earnings per share	0	200,000	200,000

Income Taxes (Narrative) (Detai

Income Taxes (Narrative) (Details) $ in Millions	9 Months Ended	12 Months Ended
	Jun. 30, 2017USD ($)	Sep. 30, 2017USD ($)	Sep. 30, 2016USD ($)	Sep. 30, 2015USD ($)	Sep. 30, 2017EUR (€)	Sep. 30, 2014USD ($)
Income Taxes [Line Items]
Cash paid for taxes (net of cash refunds)		$ 1,348.8	$ 440.8	$ 392.9
U.S. federal statutory tax rate		35.00%	35.00%	35.00%
Percentage of the undistributed earnings in countries with a statutory tax rate of 24% or higher		80.00%			80.00%
Statutory tax rate percentage or higher		24.00%			24.00%
Income tax benefit on tax losses from foreign holding company		$ 111.4
Goodwill impairment charge	$ 145.3	145.3
Goodwill impairment charge deductible for tax purposes		0
Excess tax benefits recognized under new accounting standard		17.6
Business separation additional income tax expense			$ 51.8
Foreign earnings repatriated			443.8
Deferred tax assets, valuation allowance		107.7	165.1
Debt instrument, face amount		317.2			€ 300,000,000
Cumulative undistributed earnings		6,032.5
US Income and foreign withholding taxes estimate		1,443.9
Unrecognized tax benefits		146.4	90.2	$ 83.8		$ 93.1
Unrecognized tax benefits that would impact effective tax rate		73.8	46.5
Interest and penalties related to unrecognized tax benefits		3.7	1.8	$ (1.9)
Accrued interest and penalties		12.1	$ 8.4
Federal
Income Taxes [Line Items]
Tax credit carryforwards		53.9
State
Income Taxes [Line Items]
Tax credit carryforwards		1.2
Operating loss carryforwards		75.2
Foreign
Income Taxes [Line Items]
Tax credit carryforwards		21
Operating loss carryforwards		247.3
Unused carryforwards and credits that have an expiration period		221.7
Deferred tax assets operating loss carryforwards, foreign		52.4
Energy-from-Waste (EfW)
Income Taxes [Line Items]
Deferred tax assets capital loss carryforwards		$ 49.1

Income Taxes (Income of U.S and

Income Taxes (Income of U.S and Foreign Operations Before Taxes) (Details) - USD ($) $ in Millions	3 Months Ended									12 Months Ended
	Sep. 30, 2017	Jun. 30, 2017	[1]	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2017		Sep. 30, 2016	Sep. 30, 2015
Income from Continuing Operations before Taxes
United States										$ 669.8		$ 631.7	$ 507.5
Foreign										666.2		775.9	606.3
Equity affiliates' income	$ 44.8	$ (36.9)		$ 34.2	$ 38	$ 39.3	$ 42.1	$ 32.3	$ 33.3	80.1	[1]	147	152.3
Income From Continuing Operations Before Taxes										$ 1,416.1		$ 1,554.6	$ 1,266.1
[1]	Includes the impact of an other-than-temporary impairment of an investment in an equity affiliate. For additional information, see Note 8, Summarized Financial Information of Equity Affiliates.

Income Taxes (Components of the

Income Taxes (Components of the Income Taxes Provision) (Details) - USD ($) $ in Millions	3 Months Ended												12 Months Ended
	Sep. 30, 2017	[1]	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	[2]	Jun. 30, 2016	[2]	Mar. 31, 2016	[2]	Dec. 31, 2015	Sep. 30, 2017		Sep. 30, 2016		Sep. 30, 2015
Current Tax Provision
Federal													$ 62.8		$ 171		$ 117
State													7		21.2		8.1
Foreign													229.1		178.6		165.7
Current Tax Provision													298.9		370.8		290.8
Deferred Tax Provision
Federal													1.4		45		1.5
State													6		2.8		17.8
Foreign													(45.4)		14		(9.9)
Deferred Tax Provision													(38)		61.8		9.4
Income tax provision	$ (1.3)		$ 89.3	$ 94.5	$ 78.4	$ 96.8		$ 145.9		$ 93.5		$ 96.4	$ 260.9	[1]	$ 432.6	[2]	$ 300.2
[1]	Includes the impact of a tax election benefit related to a non-U.S. subsidiary. For additional information, see Note 22, Income Taxes.
[2]	Includes income tax expense for tax costs associated with business separation. For additional information, see Note 4, Materials Technologies Separation.

Income Taxes (Effective Tax Rat

Income Taxes (Effective Tax Rate Reconciliation) (Details)	12 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2015
Income Tax Disclosure [Abstract]
U.S. federal statutory tax rate	35.00%	35.00%	35.00%
State taxes, net of federal benefit	1.00%	1.20%	1.10%
Income from equity affiliates	(2.00%)	(3.30%)	(4.00%)
Foreign tax differentials	(7.90%)	(6.60%)	(5.90%)
U.S. taxes on foreign earnings	(2.20%)	(3.10%)	(2.10%)
Domestic production activities	(0.80%)	(0.80%)	(1.00%)
Non-deductible goodwill impairment charge	3.60%	0.00%	0.00%
Non-U.S. subsidiary tax election	(7.70%)	0.00%	0.00%
Business separation costs	0.20%	4.20%	0.20%
Share-based compensation	(1.20%)	(0.00%)	(0.00%)
Other	0.40%	1.20%	0.40%
Effective Tax Rate	18.40%	27.80%	23.70%

Income Taxes (Significant Compo

Income Taxes (Significant Components of Deferred Tax Assets and Liabilities) (Details) - USD ($) $ in Millions	Sep. 30, 2017	Sep. 30, 2016
Gross Deferred Tax Assets
Retirement benefits and compensation accruals	$ 370.1	$ 527.6
Tax loss carryforwards	64.5	101.1
Tax credits and other tax carryforwards	76.1	56
Reserves and accruals	88.2	74.9
Partnership and other investments	0	5.8
Currency losses	20.7	0
Other	37.2	19.3
Valuation allowance	(107.7)	(165.1)
Deferred Tax Assets	549.1	619.6
Gross Deferred Tax Liabilities
Plant and equipment	1,035.6	985.1
Currency gains	0	46.8
Unremitted earnings of foreign entities	20.9	5.4
Partnership and other investments	5.4	0
Intangible assets	81.9	91
Other	9.2	16.7
Deferred Tax Liabilities	1,153	1,145
Deferred Tax Liabilities	$ 603.9	$ 525.4

Income Taxes (Deferred Tax Asse

Income Taxes (Deferred Tax Assets and Liabilities Included in Consolidated Financials) (Details) - USD ($) $ in Millions	Sep. 30, 2017	Sep. 30, 2016
Deferred Tax Assets
Other noncurrent assets	$ 174.5	$ 185
Deferred Tax Liabilities
Deferred income taxes	778.4	710.4
Deferred Tax Liabilities	$ 603.9	$ 525.4

Income Taxes (Reconciliation of

Income Taxes (Reconciliation of Unrecognized Tax Benefits) (Details) - USD ($) $ in Millions	12 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2015
Unrecognized Tax Benefits
Balance at beginning of year	$ 90.2	$ 83.8	$ 93.1
Additions for tax positions of the current year	47.5	12.5	4.7
Additions for tax positions of prior years	16.1	2.9	3
Reductions for tax positions of prior years	(4)	0	(2.2)
Settlements	(2)	(5.6)	(0.6)
Statute of limitations expiration	(3.2)	(2.9)	(8.3)
Foreign currency translation adjustment increase	1.8
Foreign currency translation adjustment decrease		(0.5)	(5.9)
Balance at End of Year	$ 146.4	$ 90.2	$ 83.8

Income Taxes (Summary of Income

Income Taxes (Summary of Income Tax Examinations) (Details)	12 Months Ended
	Sep. 30, 2017
Domestic | United States | Minimum
Income Tax Examination [Line Items]
Open tax year subject to examination	2,011
Domestic | United States | Maximum
Income Tax Examination [Line Items]
Open tax year subject to examination	2,017
Foreign | Canada | Minimum
Income Tax Examination [Line Items]
Open tax year subject to examination	2,013
Foreign | Canada | Maximum
Income Tax Examination [Line Items]
Open tax year subject to examination	2,017
Foreign | France | Minimum
Income Tax Examination [Line Items]
Open tax year subject to examination	2,014
Foreign | France | Maximum
Income Tax Examination [Line Items]
Open tax year subject to examination	2,017
Foreign | Germany | Minimum
Income Tax Examination [Line Items]
Open tax year subject to examination	2,012
Foreign | Germany | Maximum
Income Tax Examination [Line Items]
Open tax year subject to examination	2,017
Foreign | Netherlands | Minimum
Income Tax Examination [Line Items]
Open tax year subject to examination	2,012
Foreign | Netherlands | Maximum
Income Tax Examination [Line Items]
Open tax year subject to examination	2,017
Foreign | Spain | Minimum
Income Tax Examination [Line Items]
Open tax year subject to examination	2,011
Foreign | Spain | Maximum
Income Tax Examination [Line Items]
Open tax year subject to examination	2,017
Foreign | United Kingdom | Minimum
Income Tax Examination [Line Items]
Open tax year subject to examination	2,014
Foreign | United Kingdom | Maximum
Income Tax Examination [Line Items]
Open tax year subject to examination	2,017
Foreign | China | Minimum
Income Tax Examination [Line Items]
Open tax year subject to examination	2,012
Foreign | China | Maximum
Income Tax Examination [Line Items]
Open tax year subject to examination	2,017
Foreign | South Korea | Minimum
Income Tax Examination [Line Items]
Open tax year subject to examination	2,010
Foreign | South Korea | Maximum
Income Tax Examination [Line Items]
Open tax year subject to examination	2,017
Foreign | Taiwan | Minimum
Income Tax Examination [Line Items]
Open tax year subject to examination	2,012
Foreign | Taiwan | Maximum
Income Tax Examination [Line Items]
Open tax year subject to examination	2,017
Foreign | Chile | Minimum
Income Tax Examination [Line Items]
Open tax year subject to examination	2,013
Foreign | Chile | Maximum
Income Tax Examination [Line Items]
Open tax year subject to examination	2,017

Supplemental Information (Other

Supplemental Information (Other Receivables and Current Assets) (Details) - USD ($) $ in Millions	Sep. 30, 2017	Sep. 30, 2016
Supplemental Information [Abstract]
Derivative instruments	$ 93.9	$ 169.3
Other receivables	188	181.7
Current capital lease receivables	93.3	88.2
Prepaid inventory	0	92.8
Other	28.1	6.2
Other receivables and current assets	$ 403.3	$ 538.2

Supplemental Information (Ot150

Supplemental Information (Other Noncurrent Assets) (Details) - USD ($) $ in Millions	Sep. 30, 2017	Sep. 30, 2016
Supplemental Information [Abstract]
Derivative instruments	$ 133.9	$ 204.4
Other long-term receivables	82.1	16.9
Prepaid tax	5.1	37
Deferred tax assets	174.5	185
Pension benefits	18.4	0
Deposits	34.8	36.5
Other	193	191.2
Other noncurrent assets	$ 641.8	$ 671

Supplemental Information (Payab

Supplemental Information (Payables and Accrued Liabilities) (Details) - USD ($) $ in Millions	Sep. 30, 2017	Sep. 30, 2016
Supplemental Information [Abstract]
Trade creditors	$ 659.5	$ 578.8
Customer advances	438.9	371.2
Accrued payroll and employee benefits	187.1	217.1
Pension and postretirement benefits	22.6	35.5
Dividends payable	207.5	186.9
Outstanding payments in excess of certain cash balances	4.5	11.9
Accrued interest expense	42.2	47.9
Derivative instruments	95.9	73.5
Severance and other costs associated with business restructuring and cost reduction actions	41.5	15.7
Other	114.6	113.7
Payables and accrued liabilities	$ 1,814.3	$ 1,652.2

Supplemental Information (Ot152

Supplemental Information (Other Noncurrent Liabilities) (Details) - USD ($) $ in Millions	Sep. 30, 2017	Sep. 30, 2016
Supplemental Information [Abstract]
Pension benefits	$ 703.8	$ 1,155.1
Postretirement benefits	57	74.9
Other employee benefits	99.3	104.1
Contingencies related to uncertain tax positions	130.6	78
Advance payments	39	43.8
Environmental liabilities	72.3	70.3
Derivative instruments	36	21.8
Asset retirement obligations	144	116.1
Obligation for future contribution to an equity affiliate	94.4	94.4
Obligations associated with EfW	65.3	0
Other	170.2	58
Other noncurrent liabilities	$ 1,611.9	$ 1,816.5

Supplemental Information (Ot153

Supplemental Information (Other Income Expense) (Details) - USD ($) $ in Millions		12 Months Ended
		Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2015
Supplemental Information [Abstract]
Technology and royalty income		$ 20.8	$ 19	$ 22.8
Interest income	[1]	1.5	6.1	4.2
Foreign exchange		4.3	(7.2)	(22.6)
Sale of assets and investments		24.3	8.8	36.3
Contract settlements		14.3	12.6	0
Transition service agreements reimbursement	[2]	38.4	0	0
Other		17.4	10.1	4.8
Other income (expense), net		$ 121	$ 49.4	$ 45.5
[1]	Beginning in the second quarter of fiscal year 2017, interest income associated with our short-term investments is reflected on the consolidated income statements in "Other non-operating income (expense), net."
[2]	Reflects reimbursement for costs in support of transition services agreements with Versum for EMD and with Evonik for PMD. Refer to Note 4, Materials Technologies Separation, for additional information.

Supplemental Information (Redee

Supplemental Information (Redeemable Noncontrolling Interests) (Details) - USD ($) $ in Millions	1 Months Ended	12 Months Ended
	Jul. 31, 2015	Sep. 30, 2015
Redeemable Noncontrolling Interest [Roll Forward]
Redeemable noncontrolling interest, beginning balance		$ 287.2
Net income		11.5
Dividends		(2)
Purchase of noncontrolling interest	$ (277.9)	(277.9)
Currency translation adjustment		(18.8)
Redeemable noncontrolling interest, ending balance		$ 0

Supplemental Information (Narra

Supplemental Information (Narrative) (Details) - USD ($) $ in Millions

1 Months Ended

3 Months Ended

12 Months Ended

Jul. 31, 2015

Sep. 30, 2017

Jun. 30, 2017

[1]

Mar. 31, 2017

[1]

Dec. 31, 2016

[1]

Sep. 30, 2015

Sep. 30, 2017

Sep. 30, 2015

Supplemental Information [Abstract]

Gain on land sales

$ 12.2

[1]

$ 0

$ 0

$ 0

$ 33.6

$ 12.2

[1]

Business Acquisition [Line Items]

Payments for repurchase of redeemable noncontrolling interest

$ 277.9

$ 277.9

Indura S.A.

Business Acquisition [Line Items]

Percentage of equity interest purchased

30.50%

Ownership percentage

97.80%

97.80%

[1]

The gain is reflected on the consolidated income statements in "Other income (expense), net." For additional information, see Note 23, Supplemental Information.

Summary by Quarter (Unaudite156

Summary by Quarter (Unaudited) (Details) - USD ($) $ / shares in Units, $ in Millions		3 Months Ended																	12 Months Ended
		Sep. 30, 2017		Jun. 30, 2017		Mar. 31, 2017		Dec. 31, 2016		Sep. 30, 2016		Jun. 30, 2016		Mar. 31, 2016		Dec. 31, 2015		Sep. 30, 2015	Sep. 30, 2017		Sep. 30, 2016		Sep. 30, 2015
Quarterly Financial Information Disclosure [Abstract]
Sales		$ 2,203.1		$ 2,121.9		$ 1,980.1		$ 1,882.5		$ 1,945.5		$ 1,914.5		$ 1,777.4		$ 1,866.3			$ 8,187.6		$ 7,503.7		$ 7,824.3
Gross profit	[1]	657.8		635.7		576.3		564.4		598		594.3		564.4		570.4			2,434.2		2,327.1
Business separation costs		0	[2]	0	[2]	0	[2]	30.2	[2]	21.7	[2]	9.5	[2]	7.4	[2]	12	[2]		30.2	[2]	50.6	[2]	7.5
Business restructuring and cost reduction actions		48.4	[3]	42.7	[3]	10.3	[3]	50	[3]	10.6	[3]	13.2	[3]	10.7	[3]	0	[3]		151.4	[3]	34.5	[3]	180.1
Pension settlement loss		0.9	[4]	5.5	[4]	4.1	[4]	0	[4]	2.1	[4]	1	[4]	2	[4]	0	[4]		10.5	[4]	5.1	[4]	19.3
Goodwill and intangible asset impairment charge		0	[5]	162.1	[5]	0	[5]	0	[5]										162.1	[5]	0		0
Gain on land sale		12.2	[6]	0	[6]	0	[6]	0	[6]									$ 33.6	12.2	[6]
Operating income		455.7	[1]	252.6	[1]	391.2	[1]	328.1	[1]	391	[1]	394.6	[1]	371.6	[1]	372.5	[1]		1,427.6	[1]	1,529.7	[1]	1,233.2
Equity affiliates' income (loss)		44.8		(36.9)	[7]	34.2		38		39.3		42.1		32.3		33.3			80.1	[7]	147		152.3
Loss on extinguishment of debt										6.9	[8]	0	[8]	0	[8]	0	[8]		0		6.9	[8]	16.6
Income tax provision (benefit)		(1.3)	[9]	89.3		94.5		78.4		96.8	[10]	145.9	[10]	93.5	[10]	96.4			260.9	[9]	432.6	[10]	300.2
Net income (loss)		475		104.1		2,135.7		306.4		400.9		354.1		(465.5)		372			3,021.2		661.5		1,317.6
Income from continuing operations		474.2		104.2		304.4		251.6		289.4		250.3		278.9		280.9			1,134.4		1,099.5		933.3
Income (Loss) from discontinued operations		(5.5)		(2.3)		1,825.6	[11]	48.2		104.6		96.5		(752.2)		82.7			1,866	[11]	(468.4)		344.6
Net income (loss) attributable to Air Products		$ 468.7		$ 101.9		$ 2,130		$ 299.8		$ 394		$ 346.8		$ (473.3)		$ 363.6			$ 3,000.4		$ 631.1		$ 1,277.9
Basic Earnings Per Common Share Attributable to Air Products
Income from continuing operations (in dollars per share)		$ 2.17		$ 0.48		$ 1.40		$ 1.16		$ 1.33		$ 1.16		$ 1.29		$ 1.30			$ 5.20		$ 5.08		$ 4.34
Income (Loss) from discontinued operations (in dollars per share)		(0.02)		(0.01)		8.38		0.22		0.48		0.44		(3.48)		0.38			8.56		(2.16)		1.61
Net Income Attributable to Air Products (in dollars per share)		2.15		0.47		9.78		1.38		1.81		1.60		(2.19)		1.68			13.76		2.92		5.95
Diluted Earnings Per Common Share Attributable to Air Products
Income from continuing operations (in dollars per share)		2.15		0.47		1.39		1.15		1.32		1.15		1.28		1.29			5.16		5.04		4.29
Income (Loss) from discontinued operations (in dollars per share)		(0.02)		(0.01)		8.31		0.22		0.48		0.44		(3.45)		0.38			8.49		(2.15)		1.59
Net Income Attributable to Air Products (in dollars per share)		2.13		0.46		9.70		1.37		1.80		1.59		(2.17)		1.67			13.65		2.89		5.88
Dividends declared per common share		0.95		0.95		0.95		0.86		0.86		0.86		0.86		0.81			$ 3.71		$ 3.39		$ 3.20
Market price per common share - High		152.26		147.66		149.46		150.45		146.82		141.53		136.88		133.78
Market price per common share - Low		$ 141.88		$ 134.09		$ 133.63		$ 129		$ 127.72		$ 124.78		$ 106.63		$ 117.80
Change in Accounting Estimate [Line Items]
Operating income		$ 455.7	[1]	$ 252.6	[1]	$ 391.2	[1]	$ 328.1	[1]	$ 391	[1]	$ 394.6	[1]	$ 371.6	[1]	$ 372.5	[1]		$ 1,427.6	[1]	$ 1,529.7	[1]	$ 1,233.2
Contracts accounted for under percentage of completion
Quarterly Financial Information Disclosure [Abstract]
Operating income																			27		20
Change in Accounting Estimate [Line Items]
Operating income																			$ 27		$ 20
[1]	Changes in estimates on projects accounted for under the percentage of completion method favorably impacted income by approximately $27 in fiscal year 2017 and $20 in fiscal year 2016, primarily during the fourth quarter. For additional information, see Note 1, Major Accounting Policies (Revenue Recognition).
[2]	For additional information, see Note 4, Materials Technologies Separation.
[3]	For additional information, see Note 5, Business Restructuring and Cost Reduction Actions.
[4]	For additional information, see Note 16, Retirement Benefits.
[5]	For additional information, see Note 10, Goodwill, and Note 11, Intangible Assets.
[6]	The gain is reflected on the consolidated income statements in "Other income (expense), net." For additional information, see Note 23, Supplemental Information.
[7]	Includes the impact of an other-than-temporary impairment of an investment in an equity affiliate. For additional information, see Note 8, Summarized Financial Information of Equity Affiliates.
[8]	For additional information, see Note 15, Debt.
[9]	Includes the impact of a tax election benefit related to a non-U.S. subsidiary. For additional information, see Note 22, Income Taxes.
[10]	Includes income tax expense for tax costs associated with business separation. For additional information, see Note 4, Materials Technologies Separation.
[11]	Includes the after-tax gain on the sale of PMD. For additional information, see Note 3, Discontinued Operations.

Business Segment and Geograp157

Business Segment and Geographic Information (Narrative) (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2015
Segment Reporting Information [Line Items]
Sales	$ 2,203.1	$ 2,121.9	$ 1,980.1	$ 1,882.5	$ 1,945.5	$ 1,914.5	$ 1,777.4	$ 1,866.3	$ 8,187.6	$ 7,503.7	$ 7,824.3
Export sales to third-party customers									64.2	134.9	231.5
Industrial Gases - Global | Intersegment Eliminations
Segment Reporting Information [Line Items]
Sales									$ 239	$ 232.4	$ 242.8

Business Segment and Geograp158

Business Segment and Geographic Information (Schedule of Segment Reporting Information) (Details) - USD ($) $ in Millions	3 Months Ended																12 Months Ended
	Sep. 30, 2017		Jun. 30, 2017		Mar. 31, 2017		Dec. 31, 2016		Sep. 30, 2016		Jun. 30, 2016		Mar. 31, 2016		Dec. 31, 2015		Sep. 30, 2017		Sep. 30, 2016		Sep. 30, 2015
Segment Reporting Information [Line Items]
Sales	$ 2,203.1		$ 2,121.9		$ 1,980.1		$ 1,882.5		$ 1,945.5		$ 1,914.5		$ 1,777.4		$ 1,866.3		$ 8,187.6		$ 7,503.7		$ 7,824.3
Operating income (loss)	455.7	[1]	252.6	[1]	391.2	[1]	328.1	[1]	391	[1]	394.6	[1]	371.6	[1]	372.5	[1]	1,427.6	[1]	1,529.7	[1]	1,233.2
Depreciation and amortization																	865.8		854.6		858.5
Equity affiliates' income (loss)	44.8		$ (36.9)	[2]	$ 34.2		$ 38		39.3		$ 42.1		$ 32.3		$ 33.3		80.1	[2]	147		152.3
Expenditures for long-lived assets																	1,039.7		907.7		1,162.4
Investment in net assets of and advances to equity affiliates	1,286.9								1,283.6								1,286.9		1,283.6
Total assets	18,467.2								18,028.6								18,467.2		18,028.6		17,316.6
Operating Segments
Segment Reporting Information [Line Items]
Sales																	8,187.6		7,503.7		7,824.3
Operating income (loss)																	1,769.6		1,619.9		1,388.6
Depreciation and amortization																	865.8		854.6		858.5
Equity affiliates' income (loss)																	159.6		147		152.3
Expenditures for long-lived assets																	1,039.7		907.7		1,162.4
Investment in net assets of and advances to equity affiliates	1,286.9								1,283.6								1,286.9		1,283.6		1,249.8
Total assets	18,457								16,060.1								18,457		16,060.1		14,760
Industrial Gases - Americas | Operating Segments
Segment Reporting Information [Line Items]
Sales																	3,637		3,344.1		3,694.5
Operating income (loss)																	950.6		893.2		806.1
Depreciation and amortization																	464.4		443.6		417.5
Equity affiliates' income (loss)																	58.1		52.7		64.6
Expenditures for long-lived assets																	427.2		406.6		414.5
Investment in net assets of and advances to equity affiliates	287.5								250.6								287.5		250.6		249.7
Total assets	5,840.8								5,896.7								5,840.8		5,896.7		5,782.5
Industrial Gases - EMEA | Operating Segments
Segment Reporting Information [Line Items]
Sales																	1,780.4		1,704.4		1,866.4
Operating income (loss)																	387.1		384.6		331.3
Depreciation and amortization																	177.1		185.7		194.3
Equity affiliates' income (loss)																	47.1		36.5		42.4
Expenditures for long-lived assets																	143.2		159.5		215.6
Investment in net assets of and advances to equity affiliates	508.6								580.5								508.6		580.5		564.1
Total assets	3,276.1								3,178.6								3,276.1		3,178.6		3,324.1
Industrial Gases - Asia | Operating Segments
Segment Reporting Information [Line Items]
Sales																	1,964.7		1,720.4		1,661.3
Operating income (loss)																	531.2		451		389.3
Depreciation and amortization																	203.2		197.9		209.9
Equity affiliates' income (loss)																	53.5		57.8		46.1
Expenditures for long-lived assets																	337.8		313.3		402.5
Investment in net assets of and advances to equity affiliates	471.8								442.5								471.8		442.5		421.7
Total assets	4,412.1								4,232.7								4,412.1		4,232.7		4,159.1
Industrial Gases - Global | Operating Segments
Segment Reporting Information [Line Items]
Sales																	722.9		498.8		286.7
Operating income (loss)																	71.3		(21.3)		(51.6)
Depreciation and amortization																	8.9		7.9		16.5
Equity affiliates' income (loss)																	0.9		0		(0.8)
Expenditures for long-lived assets																	25.6		6		94.8
Investment in net assets of and advances to equity affiliates	19								10								19		10		14.3
Total assets	279.6								367.6								279.6		367.6		370.5
Corporate and Other | Operating Segments
Segment Reporting Information [Line Items]
Sales																	82.6		236		315.4
Operating income (loss)																	(170.6)		(87.6)		(86.5)
Depreciation and amortization																	12.2		19.5		20.3
Equity affiliates' income (loss)																	0		0		0
Expenditures for long-lived assets																	105.9		22.3		35
Investment in net assets of and advances to equity affiliates	0								0								0		0		0
Total assets	$ 4,648.4								$ 2,384.5								$ 4,648.4		$ 2,384.5		$ 1,123.8
[1]	Changes in estimates on projects accounted for under the percentage of completion method favorably impacted income by approximately $27 in fiscal year 2017 and $20 in fiscal year 2016, primarily during the fourth quarter. For additional information, see Note 1, Major Accounting Policies (Revenue Recognition).
[2]	Includes the impact of an other-than-temporary impairment of an investment in an equity affiliate. For additional information, see Note 8, Summarized Financial Information of Equity Affiliates.

Business Segment and Geograp159

Business Segment and Geographic Information (Reconciliation of Operating Income) (Details) - USD ($) $ in Millions		3 Months Ended																	12 Months Ended
		Sep. 30, 2017		Jun. 30, 2017		Mar. 31, 2017		Dec. 31, 2016		Sep. 30, 2016		Jun. 30, 2016		Mar. 31, 2016		Dec. 31, 2015		Sep. 30, 2015	Sep. 30, 2017		Sep. 30, 2016		Sep. 30, 2015
Segment Reporting Information [Line Items]
Business separation costs		$ 0	[1]	$ 0	[1]	$ 0	[1]	$ (30.2)	[1]	$ (21.7)	[1]	$ (9.5)	[1]	$ (7.4)	[1]	$ (12)	[1]		$ (30.2)	[1]	$ (50.6)	[1]	$ (7.5)
Business restructuring and cost reduction actions		(48.4)	[2]	(42.7)	[2]	(10.3)	[2]	(50)	[2]	(10.6)	[2]	(13.2)	[2]	(10.7)	[2]	0	[2]		(151.4)	[2]	(34.5)	[2]	(180.1)
Pension settlement loss		(0.9)	[3]	(5.5)	[3]	(4.1)	[3]	0	[3]	(2.1)	[3]	(1)	[3]	(2)	[3]	0	[3]		(10.5)	[3]	(5.1)	[3]	(19.3)
Goodwill and intangible asset impairment charge		0	[4]	(162.1)	[4]	0	[4]	0	[4]										(162.1)	[4]	0		0
Gain on previously held equity interest																			0		0		17.9
Gain on land sales		12.2	[5]	0	[5]	0	[5]	0	[5]									$ 33.6	12.2	[5]
Operating income		$ 455.7	[6]	$ 252.6	[6]	$ 391.2	[6]	$ 328.1	[6]	$ 391	[6]	$ 394.6	[6]	$ 371.6	[6]	$ 372.5	[6]		1,427.6	[6]	1,529.7	[6]	1,233.2
Segment Total
Segment Reporting Information [Line Items]
Operating income																			1,769.6		1,619.9		1,388.6
Segment Reconciling Items
Segment Reporting Information [Line Items]
Business separation costs																			(30.2)		(50.6)		(7.5)
Business restructuring and cost reduction actions																			(151.4)		(34.5)		(180.1)
Pension settlement loss																			(10.5)		(5.1)		(19.3)
Goodwill and intangible asset impairment charge																			(162.1)		0		0
Gain on previously held equity interest																			0		0		17.9
Gain on land sales	[7]																		$ 12.2		$ 0		$ 33.6
[1]	For additional information, see Note 4, Materials Technologies Separation.
[2]	For additional information, see Note 5, Business Restructuring and Cost Reduction Actions.
[3]	For additional information, see Note 16, Retirement Benefits.
[4]	For additional information, see Note 10, Goodwill, and Note 11, Intangible Assets.
[5]	The gain is reflected on the consolidated income statements in "Other income (expense), net." For additional information, see Note 23, Supplemental Information.
[6]	Changes in estimates on projects accounted for under the percentage of completion method favorably impacted income by approximately $27 in fiscal year 2017 and $20 in fiscal year 2016, primarily during the fourth quarter. For additional information, see Note 1, Major Accounting Policies (Revenue Recognition).
[7]	Reflected on the consolidated income statements in “Other income (expense), net.”

Business Segment and Geograp160

Business Segment and Geographic Information (Reconciliation of Equity Affiliates' Income) (Details) - USD ($) $ in Millions	3 Months Ended									12 Months Ended
	Sep. 30, 2017	Jun. 30, 2017		Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2017		Sep. 30, 2016	Sep. 30, 2015
Segment Reporting Information [Line Items]
Equity affiliates' income	$ 44.8	$ (36.9)	[1]	$ 34.2	$ 38	$ 39.3	$ 42.1	$ 32.3	$ 33.3	$ 80.1	[1]	$ 147	$ 152.3
Equity method investment impairment charge		$ 79.5								79.5		0	0
Segment Total
Segment Reporting Information [Line Items]
Equity affiliates' income										159.6		147	152.3
Segment Reconciling Items
Segment Reporting Information [Line Items]
Equity method investment impairment charge										$ (79.5)		$ 0	$ 0
[1]	Includes the impact of an other-than-temporary impairment of an investment in an equity affiliate. For additional information, see Note 8, Summarized Financial Information of Equity Affiliates.

Business Segment and Geograp161

Business Segment and Geographic Information (Reconciliation of Assets) (Details) - USD ($) $ in Millions	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2015
Segment Reporting Information [Line Items]
Total assets	$ 18,467.2	$ 18,028.6	$ 17,316.6
Segment Total
Segment Reporting Information [Line Items]
Total assets	18,457	16,060.1	14,760
Discontinued Operations | Segment Reconciling Items
Segment Reporting Information [Line Items]
Assets of discontinued operations	$ 10.2	$ 1,968.5	$ 2,556.6

Business Segment and Geograp162

Business Segment and Geographic Information (Schedule of Geographic Information) (Details) - USD ($) $ in Millions		3 Months Ended								12 Months Ended
		Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2015
Revenues from External Customers and Long-Lived Assets [Line Items]
Sales to External Customers		$ 2,203.1	$ 2,121.9	$ 1,980.1	$ 1,882.5	$ 1,945.5	$ 1,914.5	$ 1,777.4	$ 1,866.3	$ 8,187.6	$ 7,503.7	$ 7,824.3
Long-Lived Assets	[1]	8,440.2				8,259.7				8,440.2	8,259.7	8,237.3
United States
Revenues from External Customers and Long-Lived Assets [Line Items]
Sales to External Customers										2,886.8	2,911.7	3,369.8
Long-Lived Assets	[1]	3,407.4				3,411.4				3,407.4	3,411.4	3,502.9
Europe, including Middle East
Revenues from External Customers and Long-Lived Assets [Line Items]
Sales to External Customers										2,478.5	2,186.5	1,989.2
Long-Lived Assets	[1]	1,279				1,292.5				1,279	1,292.5	1,379.8
Asia, excluding China and India
Revenues from External Customers and Long-Lived Assets [Line Items]
Sales to External Customers										849.6	721.4	736.8
Long-Lived Assets	[1]	778.5				707				778.5	707	627.1
China
Revenues from External Customers and Long-Lived Assets [Line Items]
Sales to External Customers										1,143.4	1,020.4	957.8
Long-Lived Assets	[1]	1,737.9				1,675.8				1,737.9	1,675.8	1,682.8
Other
Revenues from External Customers and Long-Lived Assets [Line Items]
Sales to External Customers	[2]									829.3	663.7	770.7
Long-Lived Assets	[1],[2]	$ 1,237.4				$ 1,173				$ 1,237.4	$ 1,173	$ 1,044.7
[1]	Long-lived assets include plant and equipment, net.
[2]	Includes Canada, Latin America, and India.

Schedule II Valuation and Qu163

Schedule II Valuation and Qualifying Accounts Schedule II Valuation and Qualifying Accounts (Details) - USD ($) $ in Millions		12 Months Ended
		Sep. 30, 2017		Sep. 30, 2016		Sep. 30, 2015
Allowance for Doubtful Accounts
Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at Beginning of Period		$ 55		$ 48		$ 58
Additions Charged to Expense		7		9		8
Additions Charged to Other Accounts		39		13		18
Other Changes	[1]	(7)		(15)		(36)
Balance at End of Period		94		55		48
Allowance for Deferred Tax Assets
Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at Beginning of Period		165	[2],[3]	112	[3]	106
Additions Charged to Expense		6	[2]	1	[3]	0
Additions Charged to Other Accounts		7	[2]	52	[3]	9
Other Changes	[1]	(70)	[2]	0	[3]	(3)
Balance at End of Period		$ 108	[2]	$ 165	[2],[3]	$ 112	[3]
[1]	(A) Other changes related to allowance for doubtful accounts primarily includes write-offs of uncollectible trade receivables, net of recoveries. Other Changes also includes the impact of foreign currency translation adjustments.
[2]	(B) The decrease in the valuation allowance was primarily due to the utilization of federal and state loss carryforwards as a result of recognizing the gain on the sale of our PMD business. This benefit was recorded in discontinued operations. See Note 3, Discontinued Operations, for additional information.
[3]	(C) The increase in the valuation allowance was primarily due to the loss recorded on the exit from the Energy-from-Waste business. These costs were recorded in discontinued operations. See Note 3, Discontinued Operations, for additional information.