Investments and Cash - Summarized Financial Information (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Schedule of Equity Method Investments [Line Items]
Total assets	$ 18,208	$ 15,334
Total liabilities	11,708	8,629
Total equity	6,478	6,684	$ 6,645	$ 6,555
Total revenues	848	1,115	963
Total expenses	465	729	503
Net income (loss)	419	368	401
Equity Method Investment
Schedule of Equity Method Investments [Line Items]
Total assets	1,543	1,150
Total liabilities	412	499
Total equity	1,131	651
Total revenues	548	225	94
Total expenses	64	84	67
Net income (loss)	$ 484	$ 141	$ 26