Goodwill and Other Intangible Assets - Summary of Gross Amounts and Accumulated Amortization of Identifiable Intangible Assets (Parenthetical) (Detail)	12 Months Ended
	Dec. 31, 2017
Trademarks [Member]
Finite-Lived Intangible Assets [Line Items]
Amortizable intangible assets, useful life	15 years
Minimum [Member] | Customer Relationships [Member]
Finite-Lived Intangible Assets [Line Items]
Amortizable intangible assets, useful life	6 years
Minimum [Member] | Covenants not-to-Compete [Member]
Finite-Lived Intangible Assets [Line Items]
Amortizable intangible assets, useful life	4 years
Maximum [Member] | Customer Relationships [Member]
Finite-Lived Intangible Assets [Line Items]
Amortizable intangible assets, useful life	15 years
Maximum [Member] | Covenants not-to-Compete [Member]
Finite-Lived Intangible Assets [Line Items]
Amortizable intangible assets, useful life	6 years