FAIR VALUE MEASUREMENTS - Schedule of Carrying Amounts and the Fair Values of the Company's Financial Instruments (Detail) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022	Sep. 30, 2022	Dec. 31, 2021
Financial assets:
Cash and cash equivalents	$ 236,321	$ 225,949	$ 152,188	$ 305,635
Restricted cash	17,768	17,676	$ 40,246	$ 42,812
Pledged securities	177,509	157,282
Loans held for sale	758,926	396,344
Derivative assets	33,617	17,636
Financial liabilities:
Derivative liabilities	2,065	2,076
Warehouse notes payable	790,742	537,531
Notes payable	774,677	704,103
Carrying Amount
Financial assets:
Cash and cash equivalents	236,321	225,949
Restricted cash	17,768	17,676
Pledged securities	177,509	157,282
Loans held for sale	758,926	396,344
Loans held for investment, net	39,891	200,247
Derivative assets	33,617	17,636
Total financial assets	1,264,032	1,015,134
Financial liabilities:
Derivative liabilities	2,065	2,076
Contingent consideration liabilities	161,183	200,346
Warehouse notes payable	790,742	537,531
Notes payable	774,677	704,103
Total financial liabilities	1,728,667	1,444,056
Fair Value
Financial assets:
Cash and cash equivalents	236,321	225,949
Restricted cash	17,768	17,676
Pledged securities	177,509	157,282
Loans held for sale	758,926	396,344
Loans held for investment, net	40,000	200,900
Derivative assets	33,617	17,636
Total financial assets	1,264,141	1,015,787
Financial liabilities:
Derivative liabilities	2,065	2,076
Contingent consideration liabilities	161,183	200,346
Warehouse notes payable	791,178	538,134
Notes payable	788,500	708,546
Total financial liabilities	$ 1,742,926	$ 1,449,102