Workers' Compensation Claims - Summarizes Aggregate Workers' Compensation Reserve Activity (Parenthetical) (Detail) $ in Millions	6 Months Ended
Jun. 30, 2021 USD ($)
Third-party Insurance Carrier [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Claim payments related to prior period includes amount payable	$ 47.4

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.

No definition available.

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Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration