Fair Value Measurement - Assets Measured at Fair Value on a Nonrecurring Basis (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Long-lived assets, impairment charge	$ 0
Total, impairment charge	25,800,000	$ 99,300,000	$ 13,900,000
Goodwill, net book value	410,600,000	404,500,000	405,900,000
Fair Value, Measurements, Nonrecurring
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Long-lived assets, impairment charge	4,500,000	600,000	13,700,000
Other intangible assets, impairment charge	700,000	200,000	200,000
Total, impairment charge	$ 5,200,000	$ 800,000	$ 13,900,000