Summary of Assets for Segments and Corporate and Other Activities (Detail) - USD ($) $ in Millions	Jun. 30, 2022	Dec. 31, 2021
Segment Reporting Information [Line Items]
Total assets	$ 89,068	$ 99,171
Enact | Segment, Continuing Operations
Segment Reporting Information [Line Items]
Total assets	5,763	5,850
U.S. Life Insurance | Segment, Continuing Operations
Segment Reporting Information [Line Items]
Total assets	73,288	81,210
Runoff | Segment, Continuing Operations
Segment Reporting Information [Line Items]
Total assets	8,264	9,460
Corporate and Other | Segment, Continuing Operations
Segment Reporting Information [Line Items]
Total assets	$ 1,753	$ 2,651