Separate Accounts - Summary of Balances and Changes in Separate Account Liabilities (Details) - USD ($) $ in Millions	Mar. 31, 2024	Dec. 31, 2023	Mar. 31, 2023	Dec. 31, 2022
Fair Value, Separate Account Investment [Line Items]
Separate account liabilities	$ 166,225	$ 158,257
Reinsurance Agreement | Protective
Fair Value, Separate Account Investment [Line Items]
Separate account liabilities	48	46
Variable Annuities
Fair Value, Separate Account Investment [Line Items]
Separate account liabilities	118,176	113,356	$ 108,334	$ 105,573
UL and Other
Fair Value, Separate Account Investment [Line Items]
Separate account liabilities	27,007	25,150	22,162	20,920
Retirement Plan Services
Fair Value, Separate Account Investment [Line Items]
Separate account liabilities	20,986	19,699	$ 17,876	$ 16,996
Other
Fair Value, Separate Account Investment [Line Items]
Separate account liabilities	$ 56	$ 52