Employee Benefit Plans - Schedule of Allocation of Plan Assets (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Defined Benefit Plan Disclosure [Line Items]
Amount	$ 2,825	$ 2,431
Percent of Total Assets	100.00%	100.00%
Equity
Defined Benefit Plan Disclosure [Line Items]
Amount	$ 1,770	$ 1,698
Percent of Total Assets	63.00%	70.00%
Fixed Income
Defined Benefit Plan Disclosure [Line Items]
Amount	$ 818	$ 704
Percent of Total Assets	29.00%	29.00%
Cash and Cash Equivalents
Defined Benefit Plan Disclosure [Line Items]
Amount	$ 237	$ 29
Percent of Total Assets	8.00%	1.00%