Goodwill and Identifiable Intangible Assets - Significant Assumptions Used to Estimate the Fair Value of Tradename Impaired (Parenthetical) (Detail)	12 Months Ended
Dec. 31, 2020
Tradename [Member] \| Long-term Revenue Growth Rate [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Long-term revenue growth rate projection period	10 years

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