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, 2015 USD ($)
General Business Tax Credit Carryforward
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	2
Federal
Operating Loss Carryforwards and Tax Credit Carryforwards [Line Items]
Net operating loss carryforwards	5,138
State
Operating Loss Carryforwards and Tax Credit Carryforwards [Line Items]
Net operating loss carryforwards	6,014
Foreign
Operating Loss Carryforwards and Tax Credit Carryforwards [Line Items]
Net operating loss carryforwards	2,874
Tax credit carryforwards	248
Operating loss carryforwards	64
Operating loss carryforwards with an indefinite life	$ 2,800