Capitalized Servicing Assets - Changes in Capitalized Servicing Assets (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Residential Mortgage Loans [Member]
Servicing Asset at Amortized Cost [Line Items]
Amortized value, Beginning balance	$ 241,053	$ 231,204	$ 244,411
Originations	6,998	65,723	45,101
Acquired in business combination	12,133
Amortization	(65,849)	(55,874)	(58,308)
Amortized value, ending balance	194,335	241,053	231,204
Valuation allowance		(24,000)	(30,000)
Ending balance, net	194,335	217,053	201,204
Commercial Mortgage Loans [Member]
Servicing Asset at Amortized Cost [Line Items]
Amortized value, Beginning balance	132,604	133,429	130,636
Originations	24,401	33,068	29,306
Amortization	(30,614)	(33,893)	(26,513)
Amortized value, ending balance	126,391	132,604	133,429
Ending balance, net	$ 126,391	$ 132,604	$ 133,429