Fair Value - Separate Accounts Fair Value (Details) - USD ($) $ in Millions	Mar. 31, 2022	Dec. 31, 2021
Fair Value, Separate Account Investment [Line Items]
Separate accounts assets	$ 4,670	$ 5,087
Recurring
Fair Value, Separate Account Investment [Line Items]
Separate accounts assets	4,585	5,017
Recurring | Other Receivables
Fair Value, Separate Account Investment [Line Items]
Separate accounts assets	85	70
Recurring | Cash and cash equivalents
Fair Value, Separate Account Investment [Line Items]
Separate accounts assets	196	188
Recurring | Debt securities
Fair Value, Separate Account Investment [Line Items]
Separate accounts assets	3,888	4,281
Recurring | Equity securities
Fair Value, Separate Account Investment [Line Items]
Separate accounts assets	1	1
Recurring | Common/collective trusts
Fair Value, Separate Account Investment [Line Items]
Separate accounts assets	500	547
Recurring | Level 1
Fair Value, Separate Account Investment [Line Items]
Separate accounts assets	1,098	1,235
Recurring | Level 1 | Cash and cash equivalents
Fair Value, Separate Account Investment [Line Items]
Separate accounts assets	3	2
Recurring | Level 1 | Debt securities
Fair Value, Separate Account Investment [Line Items]
Separate accounts assets	1,095	1,233
Recurring | Level 1 | Equity securities
Fair Value, Separate Account Investment [Line Items]
Separate accounts assets	0	0
Recurring | Level 1 | Common/collective trusts
Fair Value, Separate Account Investment [Line Items]
Separate accounts assets	0	0
Recurring | Level 2
Fair Value, Separate Account Investment [Line Items]
Separate accounts assets	3,487	3,782
Recurring | Level 2 | Cash and cash equivalents
Fair Value, Separate Account Investment [Line Items]
Separate accounts assets	193	186
Recurring | Level 2 | Debt securities
Fair Value, Separate Account Investment [Line Items]
Separate accounts assets	2,793	3,048
Recurring | Level 2 | Equity securities
Fair Value, Separate Account Investment [Line Items]
Separate accounts assets	1	1
Recurring | Level 2 | Common/collective trusts
Fair Value, Separate Account Investment [Line Items]
Separate accounts assets	500	547
Recurring | Level 3
Fair Value, Separate Account Investment [Line Items]
Separate accounts assets	0	0
Recurring | Level 3 | Cash and cash equivalents
Fair Value, Separate Account Investment [Line Items]
Separate accounts assets	0	0
Recurring | Level 3 | Debt securities
Fair Value, Separate Account Investment [Line Items]
Separate accounts assets	0	0
Recurring | Level 3 | Equity securities
Fair Value, Separate Account Investment [Line Items]
Separate accounts assets	0	0
Recurring | Level 3 | Common/collective trusts
Fair Value, Separate Account Investment [Line Items]
Separate accounts assets	$ 0	$ 0