Segment Information - Schedule of Revenue from External Customers by Products and Services (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Segment Reporting Information [Line Items]
Total revenues	$ 4,117	$ 4,122	$ 4,282
Corporate and Other
Segment Reporting Information [Line Items]
Total revenues	12	11	7
Enact segment | Operating Segments
Segment Reporting Information [Line Items]
Total revenues	985	984	959
Closed Block | Operating Segments
Segment Reporting Information [Line Items]
Total revenues	3,120	3,127	3,316
Closed Block | Operating Segments | Long-term care insurance
Segment Reporting Information [Line Items]
Total revenues	2,345	2,310	2,463
Closed Block | Operating Segments | Life insurance
Segment Reporting Information [Line Items]
Total revenues	669	704	738
Closed Block | Operating Segments | Annuities
Segment Reporting Information [Line Items]
Total revenues	$ 106	$ 113	$ 115