Income Taxes - Schedule of Significant Components of Deferred Income Tax Assets and Liabilities (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Assets
Pension Plans	$ 71	$ 79
Other Employee Benefit Plans	127	146
Other	426	529
Total	624	754
Liabilities
Accelerated Depreciation	7,020	6,799
Other	565	645
Total	7,585	7,444
Net Deferred Income Tax Liabilities	$ 6,961	$ 6,690