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]
Carrying value of investments accounted for under the equity method	$ 4,800
Total assets	216,151	$ 247,255
Total liabilities	209,287	231,144
Net income (loss)	(64)	66	$ (1,306)
Nonconsolidated Equity Method Investment
Schedule of Equity Method Investments [Line Items]
Unfunded commitments	1,600
Total assets	879,800	811,700
Total liabilities	109,200	103,200
Net income (loss)	$ (12,800)	$ 22,600	$ 37,700