Income Taxes - Schedule of Approximate Amounts of Federal, State and Foreign Net Operating Loss Carryforwards and Foreign Tax Credit, General Business Credit and Minimum Tax credit Carryforwards (Details) $ in Millions	Dec. 31, 2016 USD ($)
General Business Tax Credit
Operating Loss Carryforwards and Tax Credit Carryforwards [Line Items]
Tax credit carryforwards	$ 12
Minimum Tax Credit
Operating Loss Carryforwards and Tax Credit Carryforwards [Line Items]
Tax credit carryforwards	18
Federal
Operating Loss Carryforwards and Tax Credit Carryforwards [Line Items]
Net operating loss carryforwards	4,766
State
Operating Loss Carryforwards and Tax Credit Carryforwards [Line Items]
Net operating loss carryforwards	5,893
Foreign
Operating Loss Carryforwards and Tax Credit Carryforwards [Line Items]
Net operating loss carryforwards	3,079
Tax credit carryforwards	289
Operating loss carryforwards	66
Operating loss carryforwards with an indefinite life	$ 3,000