Investments (Collectively Significant Equity Method Investments - Narrative) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Schedule of Equity Method Investments [Line Items]
Equity Method Investments	$ 25,700
Unfunded Commitments For Investments Accounted For Under Equity Method	7,800
Total Assets	666,611	$ 759,708
Total Liabilities	639,324	691,959
Net income (loss)	2,558	6,575	$ 5,418
Equity Method Investment, Nonconsolidated Investee or Group of Investees [Member]
Schedule of Equity Method Investments [Line Items]
Total Assets	1,200,000	1,100,000
Total Liabilities	148,900	149,400
Net income (loss)	$ (11,800)	$ 231,000	$ 41,600