Incentive Plans - Summary of Activity Relating to PIPRs, including PRPUs (Parenthetical) (Detail)	9 Months Ended
Sep. 30, 2020 $ / shares shares
PRPUs [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Units, Granted \| shares	486,611
Weighted average grant date fair value \| $ / shares	$ 40.61
PRPUs [Member] \| Target Of P R P U S
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Units, Granted \| shares	1,050,778
Other Profits Interest Participation Rights
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted average grant date fair value \| $ / shares	$ 40.30

The number of grants made during the period on other than stock (or unit) option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, performance target plan).

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)(2)(iii)(1)
-URI http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901

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- Definition

Per share or unit weighted-average fair value of nonvested award under share-based payment arrangement. Excludes share and unit options.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)(2)(i)-(ii)
-URI http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901

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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.

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