Fair Value Measurements - Fair Value of Assets and Liabilities Measured on Recurring and Nonrecurring Basis (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
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	$ 63.8	$ 114.9
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	44.5
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	1.4	88.3
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	1.4	88.3
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	44.5
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	63.8	114.9
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	24.5	0.7
Total Gains (Losses)	(1.6)	(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	$ 24.5	$ 0.7