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Supplemental Cash Flow Information - Schedule of Noncash Investing and Financing Activities (Detail) - USD ($) $ in Millions | 9 Months Ended
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Sep. 30, 2021 | Sep. 30, 2020
Supplemental Cash Flow Elements [Abstract] |  |
Right-of-use assets obtained in exchange for new finance lease liabilities | $ 177.8 | $ 15.0
Right-of-use assets obtained in exchange for new operating lease liabilities | 17.3 | 29.3
Accrued liabilities for purchases of property, plant and equipment | 28.6 | 30.5
Remeasurement of operating lease right-of-use assets | $ (12.4) | $ 1.9

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- Definition Future cash outflow to pay for purchases of fixed assets that have occurred. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 50 -Paragraph 5 -URI http://asc.fasb.org/extlink&oid=123431023&loc=d3e4332-108586 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 50 -Paragraph 4 -URI http://asc.fasb.org/extlink&oid=123431023&loc=d3e4313-108586 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 50 -Paragraph 3 -URI http://asc.fasb.org/extlink&oid=123431023&loc=d3e4304-108586 + Details
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