Investments - Schedule of Increase (Decrease) in Payables for Collateral on Investments (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Investments [Abstract]
Collateral payable for derivative investments	$ 1,966	$ (2,291)	$ 2,599
Securities pledged under securities lending agreements	(93)	57	125
Investments pledged for FHLBI	(480)	0	0
Total increase (decrease) in payables for collateral on investments	$ 1,393	$ (2,234)	$ 2,724