The Company and Significant Accounting Policies - Fair Value Assets and Liabilities Measured on Recurring Basis and Nonrecurring Basis (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Sep. 30, 2022
Fair Value, Measurements, Recurring | Contingent Consideration
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Fair Value and Carrying Value on Liabilities	$ 114.9	$ 56.4
Fair Value, Measurements, Recurring | Corporate Bonds and Notes
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Fair Value and Carrying Value on Assets		42.5
Fair Value, Measurements, Recurring | Asset-Backed Securities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Fair Value and Carrying Value on Assets		0.7
Fair Value, Measurements, Recurring | Money Market Account
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Fair Value and Carrying Value on Assets	88.3	2.0
Fair Value, Measurements, Recurring | Level 1 | Money Market Account
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Fair Value and Carrying Value on Assets	88.3	2.0
Fair Value, Measurements, Recurring | Level 2 | Corporate Bonds and Notes
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Fair Value and Carrying Value on Assets		42.5
Fair Value, Measurements, Recurring | Level 2 | Asset-Backed Securities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Fair Value and Carrying Value on Assets		0.7
Fair Value, Measurements, Recurring | Level 3 | Contingent Consideration
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Fair Value and Carrying Value on Liabilities	114.9	$ 56.4
Fair Value, Measurements, Nonrecurring | FCC Licenses
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Fair Value and Carrying Value on Assets	0.7
Total Gains (Losses)	(0.1)
Fair Value, Measurements, Nonrecurring | Level 3 | FCC Licenses
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Fair Value and Carrying Value on Assets	$ 0.7