Reinsurance (Effect of Reinsurance on Life Insurance In Force) (Details) - USD ($) $ in Millions	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Reinsurance Disclosures [Abstract]
Reinsurance Premiums for Insurance Companies, by Product Segment, Gross Amount	$ 924	$ 1,027	$ 1,117
Reinsurance Premiums for Insurance Companies, by Product Segment, Amount Assumed from Other Companies	3,704,061	3,400,735	3,467,054
Reinsurance Premiums for Insurance Companies, by Product Segment, Amount Ceded to Other Companies	69,242	151,569	166,842
Reinsurance Premiums for Insurance Companies, by Product Segment, Net Amount	$ 3,635,743	$ 3,250,193	$ 3,301,329
Reinsurance Premiums for Insurance Companies, by Product Segment, Percentage of Amount Assumed to Net	101.90%	104.60%	105.00%