Stock-Based Incentive Plans - Additional Information (Detail) $ in Millions	9 Months Ended
Sep. 30, 2023 USD ($) plan shares	Dec. 31, 2022 shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of current benefit plans \| plan	2
Number of benefit plans \| plan	9
Number of expired benefit plans \| plan	7
Restricted Class A Common Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted shares, vesting period (in years)	3 years
Number of shares of restricted class A common stock outstanding (in shares)	1,539,475	1,883,784
Unrecognized compensation cost relating to nonvested share-based compensation \| $	$ 38.4
Unrecognized compensation cost expected to be recognized over weighted average period (in years)	1 year
Expired Plans
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares available under plan (in shares)	0
Vest in 2023 \| Restricted Class A Common Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares of restricted class A common stock outstanding (in shares)	271,668
Vest in 2024 \| Restricted Class A Common Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares of restricted class A common stock outstanding (in shares)	844,109
Vest in 2025 \| Restricted Class A Common Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares of restricted class A common stock outstanding (in shares)	423,698
Class A Common Stock \| Stock Incentive Current Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Maximum number of shares available under plan (in shares)	10,400,000
Number of shares available under plan (in shares)	8,677,254

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