Sales of Businesses - Narrative (Details) - USD ($) $ in Millions	3 Months Ended			6 Months Ended
	Jun. 30, 2021	Dec. 31, 2020	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Proceeds from sale of businesses				$ 3,547	$ 0
Realized gain on subsidiary	$ 4		$ 0	$ 4	$ 0
Neon Capital Limited
Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Proceeds from sale of businesses		$ 6