v3.26.1
Fair Value Hierarchy - Fair Value of Loans Held for Investment by Level (Detail) - USD ($)
$ in Millions
Jun. 30, 2026
Mar. 31, 2026
Dec. 31, 2025
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]      
Fair Value $ 4,640   $ 4,905
Level 1      
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]      
Fair Value 0   0
Level 2      
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]      
Fair Value 4,088   4,359
Level 3      
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]      
Fair Value 552 $ 591 546
Corporate      
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]      
Fair Value 615   326
Corporate | Level 1      
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]      
Fair Value 0   0
Corporate | Level 2      
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]      
Fair Value 313   36
Corporate | Level 3      
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]      
Fair Value 302   290
Commercial real estate      
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]      
Fair Value 408   420
Commercial real estate | Level 1      
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]      
Fair Value 0   0
Commercial real estate | Level 2      
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]      
Fair Value 346   356
Commercial real estate | Level 3      
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]      
Fair Value 62   64
Residential real estate      
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]      
Fair Value 3,104   3,257
Residential real estate | Level 1      
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]      
Fair Value 0   0
Residential real estate | Level 2      
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]      
Fair Value 3,073   3,222
Residential real estate | Level 3      
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]      
Fair Value 31   35
Other collateralized      
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]      
Fair Value 487   855
Other collateralized | Level 1      
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]      
Fair Value 0   0
Other collateralized | Level 2      
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]      
Fair Value 356   717
Other collateralized | Level 3      
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]      
Fair Value 131   138
Other      
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]      
Fair Value 26   47
Other | Level 1      
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]      
Fair Value 0   0
Other | Level 2      
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]      
Fair Value 0   28
Other | Level 3      
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]      
Fair Value $ 26   $ 19