Investments (Collectively Significant Equity Method Investments - Narrative) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Schedule of Equity Method Investments [Line Items]
Equity Method Investments	$ 23,500
Unfunded Commitments For Investments Accounted For Under Equity Method	7,600
Total Assets	759,708	$ 795,146
Total Liabilities	691,959	720,329
Net income (loss)	6,575	5,418	$ 5,909
Equity Method Investment, Nonconsolidated Investee or Group of Investees [Member]
Schedule of Equity Method Investments [Line Items]
Total Assets	1,100,000	704,500
Total Liabilities	149,400	99,400
Net income (loss)	$ 231,000	$ 41,600	$ 47,000