Acquisitions	12 Months Ended
Sep. 30, 2021
Business Combination and Asset Acquisition [Abstract]
Acquisitions	ACQUISITIONS Fiscal Year 2021 Gain on Exchange With Joint Venture Partner As of 30 September 2020, we held a 50% ownership interest in Tyczka Industrie-Gases GmbH ("TIG"), a joint venture in Germany with the Tyczka Group that is primarily a merchant gases business. We accounted for this arrangement as an equity method investment in our Industrial Gases – EMEA segment. Effective 23 February 2021 (the "acquisition date"), we agreed with our joint venture partner to separate TIG into two separate businesses. On the acquisition date, we acquired a portion of the business on a 100% basis, and our partner paid us $10.8 to acquire the rest of the business. The exchange resulted in a gain of $36.8 ($27.3 after-tax), which is reflected as “Gain on exchange with joint venture partner” on our consolidated income statements for the fiscal year ended 30 September 2021. The gain included $12.7 from the revaluation of our previously held equity interest in the portion of the business that we retained and $24.1 from the sale of our equity interest in the remaining business. The gain was not recorded in segment results. We estimated an acquisition date fair value of $15.4 for our previously held equity interest in the acquired portion of the business using a market approach, which considered historical earnings and the application of a market-based multiple derived from comparable transactions. We accounted for the acquisition as a business combination within our Industrial Gases – EMEA segment. As a result of the acquisition, we recognized intangible assets of $16.7 for customer relationships, goodwill of $14.5, and plant and equipment of $10.3. The customer relationships have a weighted-average useful life of approximately 15 years. The acquired assets were recorded at their estimated fair values based primarily on a preliminary purchase price allocation. We may record adjustments to these assets during the preliminary purchase price allocation period, which could be up to one year from the acquisition date. We expect the acquisition to allow us to have more control over the business we retained and to serve customers more effectively. The results of this business did not materially impact our consolidated income statements for the periods presented. Fiscal Year 2020 Asset Acquisition On 17 April 2020, we acquired five operating hydrogen production plants from PBF Energy Inc. ("PBF") and commenced contractual long-term supply of hydrogen from those plants to PBF's refineries. We accounted for the transaction as an asset acquisition and recorded the aggregate purchase price of $580 to plant and equipment on our consolidated balance sheets. Business Combinations We completed three acquisitions on 1 July 2020 that were accounted for as business combinations. These acquisitions had an aggregate purchase price, net of cash acquired, of $185.4. The largest of these acquisitions was the purchase of Oxygen & Argon Works Ltd., the leading manufacturer and marketer of industrial gases in Israel, primarily offering merchant gas products. The results of this business are consolidated within our Industrial Gases – EMEA segment. Fiscal Year 2019 As further discussed below, we completed three business combinations in fiscal year 2019. Exchange of Equity Affiliate Investments We previously held 50% ownership interests in High-Tech Gases (Beijing) Co., Ltd. ("High-Tech Gases") and WuXi Hi-Tech Gas Co., Ltd. ("WuXi"), both of which were joint ventures with another industrial gas company in China. We accounted for these arrangements as equity method investments in our Industrial Gases – Asia segment through 30 April 2019. On 1 May 2019, we acquired our partner's 50% interest in WuXi in exchange for our 50% interest in High-Tech Gases. The exchange resulted in a net gain of $29.1, of which $15.0 resulted from the revaluation of our previously held equity interest in WuXi to its acquisition date fair value and $14.1 resulted from the disposition of our interest in High-Tech Gases. The net gain is reflected as "Gain on exchange with joint venture partner" on our consolidated income statements in fiscal year 2019 and was not recorded in results of the Industrial Gases – Asia segment. We revalued our previously held 50% equity interest in WuXi based on an estimated acquisition date fair value of $27.0. We calculated this fair value using a discounted cash flow analysis under the income approach, which required estimates and assumptions regarding projected revenue growth, customer attrition rates, profit margin, and discount rate. The acquisition of the remaining interest in WuXi was accounted for as a business combination. The results of this business are consolidated within our Industrial Gases – Asia segment. Other Fiscal Year 2019 Business Combinations The remaining business combinations completed in fiscal year 2019 had total consideration, net of cash acquired, of $126.6. The largest of these business combinations was the acquisition of ACP Europe SA ("ACP"), the largest independent carbon dioxide business in Continental Europe. The results of this business are consolidated within our Industrial Gases – EMEA segment.
Business Combinations	ACQUISITIONS Fiscal Year 2021 Gain on Exchange With Joint Venture Partner As of 30 September 2020, we held a 50% ownership interest in Tyczka Industrie-Gases GmbH ("TIG"), a joint venture in Germany with the Tyczka Group that is primarily a merchant gases business. We accounted for this arrangement as an equity method investment in our Industrial Gases – EMEA segment. Effective 23 February 2021 (the "acquisition date"), we agreed with our joint venture partner to separate TIG into two separate businesses. On the acquisition date, we acquired a portion of the business on a 100% basis, and our partner paid us $10.8 to acquire the rest of the business. The exchange resulted in a gain of $36.8 ($27.3 after-tax), which is reflected as “Gain on exchange with joint venture partner” on our consolidated income statements for the fiscal year ended 30 September 2021. The gain included $12.7 from the revaluation of our previously held equity interest in the portion of the business that we retained and $24.1 from the sale of our equity interest in the remaining business. The gain was not recorded in segment results. We estimated an acquisition date fair value of $15.4 for our previously held equity interest in the acquired portion of the business using a market approach, which considered historical earnings and the application of a market-based multiple derived from comparable transactions. We accounted for the acquisition as a business combination within our Industrial Gases – EMEA segment. As a result of the acquisition, we recognized intangible assets of $16.7 for customer relationships, goodwill of $14.5, and plant and equipment of $10.3. The customer relationships have a weighted-average useful life of approximately 15 years. The acquired assets were recorded at their estimated fair values based primarily on a preliminary purchase price allocation. We may record adjustments to these assets during the preliminary purchase price allocation period, which could be up to one year from the acquisition date. We expect the acquisition to allow us to have more control over the business we retained and to serve customers more effectively. The results of this business did not materially impact our consolidated income statements for the periods presented. Fiscal Year 2020 Asset Acquisition On 17 April 2020, we acquired five operating hydrogen production plants from PBF Energy Inc. ("PBF") and commenced contractual long-term supply of hydrogen from those plants to PBF's refineries. We accounted for the transaction as an asset acquisition and recorded the aggregate purchase price of $580 to plant and equipment on our consolidated balance sheets. Business Combinations We completed three acquisitions on 1 July 2020 that were accounted for as business combinations. These acquisitions had an aggregate purchase price, net of cash acquired, of $185.4. The largest of these acquisitions was the purchase of Oxygen & Argon Works Ltd., the leading manufacturer and marketer of industrial gases in Israel, primarily offering merchant gas products. The results of this business are consolidated within our Industrial Gases – EMEA segment. Fiscal Year 2019 As further discussed below, we completed three business combinations in fiscal year 2019. Exchange of Equity Affiliate Investments We previously held 50% ownership interests in High-Tech Gases (Beijing) Co., Ltd. ("High-Tech Gases") and WuXi Hi-Tech Gas Co., Ltd. ("WuXi"), both of which were joint ventures with another industrial gas company in China. We accounted for these arrangements as equity method investments in our Industrial Gases – Asia segment through 30 April 2019. On 1 May 2019, we acquired our partner's 50% interest in WuXi in exchange for our 50% interest in High-Tech Gases. The exchange resulted in a net gain of $29.1, of which $15.0 resulted from the revaluation of our previously held equity interest in WuXi to its acquisition date fair value and $14.1 resulted from the disposition of our interest in High-Tech Gases. The net gain is reflected as "Gain on exchange with joint venture partner" on our consolidated income statements in fiscal year 2019 and was not recorded in results of the Industrial Gases – Asia segment. We revalued our previously held 50% equity interest in WuXi based on an estimated acquisition date fair value of $27.0. We calculated this fair value using a discounted cash flow analysis under the income approach, which required estimates and assumptions regarding projected revenue growth, customer attrition rates, profit margin, and discount rate. The acquisition of the remaining interest in WuXi was accounted for as a business combination. The results of this business are consolidated within our Industrial Gases – Asia segment. Other Fiscal Year 2019 Business Combinations The remaining business combinations completed in fiscal year 2019 had total consideration, net of cash acquired, of $126.6. The largest of these business combinations was the acquisition of ACP Europe SA ("ACP"), the largest independent carbon dioxide business in Continental Europe. The results of this business are consolidated within our Industrial Gases – EMEA segment.

Acquisitions

12 Months Ended

Sep. 30, 2021

Business Combination and Asset Acquisition [Abstract]

ACQUISITIONS

Fiscal Year 2021

Gain on Exchange With Joint Venture Partner

As of 30 September 2020, we held a 50% ownership interest in Tyczka Industrie-Gases GmbH ("TIG"), a joint venture in Germany with the Tyczka Group that is primarily a merchant gases business. We accounted for this arrangement as an equity method investment in our Industrial Gases – EMEA segment.

Effective 23 February 2021 (the "acquisition date"), we agreed with our joint venture partner to separate TIG into two separate businesses. On the acquisition date, we acquired a portion of the business on a 100% basis, and our partner paid us $10.8 to acquire the rest of the business. The exchange resulted in a gain of $36.8 ($27.3 after-tax), which is reflected as “Gain on exchange with joint venture partner” on our consolidated income statements for the fiscal year ended 30 September 2021. The gain included $12.7 from the revaluation of our previously held equity interest in the portion of the business that we retained and $24.1 from the sale of our equity interest in the remaining business. The gain was not recorded in segment results.

We estimated an acquisition date fair value of $15.4 for our previously held equity interest in the acquired portion of the business using a market approach, which considered historical earnings and the application of a market-based multiple derived from comparable transactions.

We accounted for the acquisition as a business combination within our Industrial Gases – EMEA segment. As a result of the acquisition, we recognized intangible assets of $16.7 for customer relationships, goodwill of $14.5, and plant and equipment of $10.3. The customer relationships have a weighted-average useful life of approximately 15 years.

The acquired assets were recorded at their estimated fair values based primarily on a preliminary purchase price allocation. We may record adjustments to these assets during the preliminary purchase price allocation period, which could be up to one year from the acquisition date.

We expect the acquisition to allow us to have more control over the business we retained and to serve customers more effectively. The results of this business did not materially impact our consolidated income statements for the periods presented.

Fiscal Year 2020

Asset Acquisition

On 17 April 2020, we acquired five operating hydrogen production plants from PBF Energy Inc. ("PBF") and commenced contractual long-term supply of hydrogen from those plants to PBF's refineries. We accounted for the transaction as an asset acquisition and recorded the aggregate purchase price of $580 to plant and equipment on our consolidated balance sheets.

Business Combinations

We completed three acquisitions on 1 July 2020 that were accounted for as business combinations. These acquisitions had an aggregate purchase price, net of cash acquired, of $185.4. The largest of these acquisitions was the purchase of Oxygen & Argon Works Ltd., the leading manufacturer and marketer of industrial gases in Israel, primarily offering merchant gas products. The results of this business are consolidated within our Industrial Gases – EMEA segment.

Fiscal Year 2019

As further discussed below, we completed three business combinations in fiscal year 2019.

Exchange of Equity Affiliate Investments

We previously held 50% ownership interests in High-Tech Gases (Beijing) Co., Ltd. ("High-Tech Gases") and WuXi Hi-Tech Gas Co., Ltd. ("WuXi"), both of which were joint ventures with another industrial gas company in China. We accounted for these arrangements as equity method investments in our Industrial Gases – Asia segment through 30 April 2019.

On 1 May 2019, we acquired our partner's 50% interest in WuXi in exchange for our 50% interest in High-Tech Gases. The exchange resulted in a net gain of $29.1, of which $15.0 resulted from the revaluation of our previously held equity interest in WuXi to its acquisition date fair value and $14.1 resulted from the disposition of our interest in High-Tech Gases. The net gain is reflected as "Gain on exchange with joint venture partner" on our consolidated income statements in fiscal year 2019 and was not recorded in results of the Industrial Gases – Asia segment.

We revalued our previously held 50% equity interest in WuXi based on an estimated acquisition date fair value of $27.0. We calculated this fair value using a discounted cash flow analysis under the income approach, which required estimates and assumptions regarding projected revenue growth, customer attrition rates, profit margin, and discount rate.

The acquisition of the remaining interest in WuXi was accounted for as a business combination. The results of this business are consolidated within our Industrial Gases – Asia segment.

Other Fiscal Year 2019 Business Combinations

The remaining business combinations completed in fiscal year 2019 had total consideration, net of cash acquired, of $126.6. The largest of these business combinations was the acquisition of ACP Europe SA ("ACP"), the largest independent carbon dioxide business in Continental Europe. The results of this business are consolidated within our Industrial Gases – EMEA segment.

Business Combinations

ACQUISITIONS

Fiscal Year 2021

Gain on Exchange With Joint Venture Partner

Fiscal Year 2020

Asset Acquisition

Business Combinations

Fiscal Year 2019

As further discussed below, we completed three business combinations in fiscal year 2019.

Exchange of Equity Affiliate Investments

The acquisition of the remaining interest in WuXi was accounted for as a business combination. The results of this business are consolidated within our Industrial Gases – Asia segment.

Other Fiscal Year 2019 Business Combinations