Commitments and Contingencies - Off-Balance-Sheet Originate Loans and Letters of Credit (Detail) - USD ($) $ in Millions	Dec. 31, 2022	Dec. 31, 2021
Loss Contingencies [Line Items]
Commitments	$ 22,368
Multi-family and commercial real estate
Loss Contingencies [Line Items]
Commitments	216
One-to-four family including interest rate locks
Loss Contingencies [Line Items]
Commitments	2,066
Acquisition, Development, and Construction
Loss Contingencies [Line Items]
Commitments	3,539
Warehouse loan commitments
Loss Contingencies [Line Items]
Commitments	8,042
Total loan commitments
Loss Contingencies [Line Items]
Commitments	21,827	$ 2,800
Commercial, performance stand-by, and financial stand-by letters of credit
Loss Contingencies [Line Items]
Commitments	541	$ 291
Other loan commitments
Loss Contingencies [Line Items]
Commitments	$ 7,964