Income Taxes (Operating and Capital Loss Carryforwards) (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Federal
Operating Loss Carryforwards [Line Items]
Operating loss carryforwards	$ 33	$ 0
State and local
Operating Loss Carryforwards [Line Items]
Operating loss carryforwards	2,005	2,152
Foreign operations
Operating Loss Carryforwards [Line Items]
Operating loss carryforwards	203	99
Foreign operations | Operating loss expiring between 2018 and 2035
Operating Loss Carryforwards [Line Items]
Operating loss carryforwards	124
Foreign operations | Operating loss unlimited carryforward
Operating Loss Carryforwards [Line Items]
Operating loss carryforwards	79
Federal foreign
Operating Loss Carryforwards [Line Items]
Operating loss carryforwards	$ 4	$ 0