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]
Carrying value of investments accounted for under the equity method	$ 4,300
Total assets	247,255	$ 235,288
Total liabilities	231,144	217,173
Net income (loss)	66	(1,306)	$ (809)
Nonconsolidated Equity Method Investment
Schedule of Equity Method Investments [Line Items]
Unfunded commitments	1,700
Total assets	811,700	503,700
Total liabilities	103,200	62,900
Net income (loss)	$ 22,600	$ 37,700	$ 33,300