Fair Value - Separate Accounts Fair Value (Details) - USD ($) $ in Millions	Jun. 30, 2026	Dec. 31, 2025
Balance Sheet Location [Axis]: us-gaap:OtherAssetsNoncurrent
Fair Value, Separate Account Investment [Line Items]
Separate Account Asset	$ 40
Total
Fair Value, Separate Account Investment [Line Items]
Separate Account Asset	1,974	$ 1,994
Cash and cash equivalents
Fair Value, Separate Account Investment [Line Items]
Separate Account Asset	146	156
Debt securities:
Fair Value, Separate Account Investment [Line Items]
Separate Account Asset	380	393
Common/collective trusts
Fair Value, Separate Account Investment [Line Items]
Separate Account Asset	1,448	1,445
Level 1 \| Total
Fair Value, Separate Account Investment [Line Items]
Separate Account Asset	12	31
Level 1 \| Cash and cash equivalents
Fair Value, Separate Account Investment [Line Items]
Separate Account Asset	1	1
Level 1 \| Debt securities:
Fair Value, Separate Account Investment [Line Items]
Separate Account Asset	11	30
Level 1 \| Common/collective trusts
Fair Value, Separate Account Investment [Line Items]
Separate Account Asset	0	0
Level 2 \| Total
Fair Value, Separate Account Investment [Line Items]
Separate Account Asset	1,961	1,961
Level 2 \| Cash and cash equivalents
Fair Value, Separate Account Investment [Line Items]
Separate Account Asset	145	155
Level 2 \| Debt securities:
Fair Value, Separate Account Investment [Line Items]
Separate Account Asset	368	361
Level 2 \| Common/collective trusts
Fair Value, Separate Account Investment [Line Items]
Separate Account Asset	1,448	1,445
Level 3 \| Total
Fair Value, Separate Account Investment [Line Items]
Separate Account Asset	1	2
Level 3 \| Cash and cash equivalents
Fair Value, Separate Account Investment [Line Items]
Separate Account Asset	0	0
Level 3 \| Debt securities:
Fair Value, Separate Account Investment [Line Items]
Separate Account Asset	1	2
Level 3 \| Common/collective trusts
Fair Value, Separate Account Investment [Line Items]
Separate Account Asset	$ 0	$ 0