FAIR VALUE MEASUREMENTS - Schedule of Carrying Amounts and the Fair Values of the Company's Financial Instruments (Detail) - USD ($) $ in Thousands	Sep. 30, 2024	Dec. 31, 2023	Sep. 30, 2023	Dec. 31, 2022
Financial assets:
Cash and cash equivalents	$ 179,759	$ 328,698	$ 236,321	$ 225,949
Restricted cash	39,827	21,422	$ 17,768	$ 17,676
Pledged securities	203,945	184,081
Loans held for sale	1,024,984	594,998
Derivative assets	33,699	31,451
Financial liabilities:
Derivative liabilities	4,026	28,247
Warehouse notes payable	1,019,850	596,178
Notes payable	769,376	773,358
Carrying Amount
Financial assets:
Cash and cash equivalents	179,759	328,698
Restricted cash	39,827	21,422
Pledged securities	203,945	184,081
Loans held for sale	1,024,984	594,998
Loans held for investment, net	52,767	40,056
Derivative assets	33,699	31,451
Total financial assets	1,534,981	1,200,706
Financial liabilities:
Derivative liabilities	4,026	28,247
Contingent consideration liabilities	79,359	113,546
Warehouse notes payable	1,019,850	596,178
Notes payable	769,376	773,358
Total financial liabilities	1,872,611	1,511,329
Fair Value
Financial assets:
Cash and cash equivalents	179,759	328,698
Restricted cash	39,827	21,422
Pledged securities	203,945	184,081
Loans held for sale	1,024,984	594,998
Loans held for investment, net	52,767	40,139
Derivative assets	33,699	31,451
Total financial assets	1,534,981	1,200,789
Financial liabilities:
Derivative liabilities	4,026	28,247
Contingent consideration liabilities	79,359	113,546
Warehouse notes payable	1,020,236	596,428
Notes payable	780,487	786,500
Total financial liabilities	$ 1,884,108	$ 1,524,721