Fair value of financial instruments - Assets, Liabilities and Temporary Equity Measured at Fair Value on Recurring Basis (Detail) - USD ($) $ in Thousands	Jun. 30, 2024	Dec. 31, 2023
Assets
Investments in equity securities	$ 37,179	$ 37,391
Fair Value, Measurements, Recurring
Assets
Investments in equity securities	37,179
Liabilities
Contingent earn-out obligations	17,898
Temporary equity
Noncontrolling interests subject to put provisions	1,574,840
Fair Value, Measurements, Recurring | Interest rate cap agreements
Assets
Interest rate cap agreements	51,223
Fair Value, Measurements, Recurring | Quoted prices in active markets for identical assets (Level 1)
Assets
Investments in equity securities	37,179
Liabilities
Contingent earn-out obligations
Temporary equity
Noncontrolling interests subject to put provisions
Fair Value, Measurements, Recurring | Quoted prices in active markets for identical assets (Level 1) | Interest rate cap agreements
Assets
Interest rate cap agreements
Fair Value, Measurements, Recurring | Significant other observable inputs (Level 2)
Assets
Investments in equity securities
Liabilities
Contingent earn-out obligations
Temporary equity
Noncontrolling interests subject to put provisions
Fair Value, Measurements, Recurring | Significant other observable inputs (Level 2) | Interest rate cap agreements
Assets
Interest rate cap agreements	51,223
Fair Value, Measurements, Recurring | Significant unobservable inputs (Level 3)
Assets
Investments in equity securities
Liabilities
Contingent earn-out obligations	17,898
Temporary equity
Noncontrolling interests subject to put provisions	1,574,840
Fair Value, Measurements, Recurring | Significant unobservable inputs (Level 3) | Interest rate cap agreements
Assets
Interest rate cap agreements