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Segments - Total Assets for Reportable Segments (Parenthetical) (Detail) - USD ($) $ in Millions | 6 Months Ended | 12 Months Ended
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Jun. 30, 2021 | Dec. 31, 2020
Processing and Storage |  |
Segment Reporting Information [Line Items] |  |
Cash contributed to acquire equity investments | $ 102.5 | $ 108.4

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- Definition The cash outflow associated with the purchase of or advances to an equity method investments, which are investments in joint ventures and entities in which the entity has an equity ownership interest normally of 20 to 50 percent and exercises significant influence. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 13 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=121586364&loc=d3e3213-108585 + Details
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Balance Type: | credit
Period Type: | duration

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- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. + References No definition available. + Details
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Period Type: | duration

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- Details
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Namespace Prefix: |
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