Contingencies (Impact of Legal Expenses Paid or Incurred to Date and Settlements Paid or Deemed Final) (Details) $ in Millions	6 Months Ended
	Jun. 30, 2017 USD ($)
Loss Contingencies [Line Items]
Beginning Balance	$ 62
Settlements paid
Legal expenses incurred and/or paid	1
Ending Balance	63
Deductible [Member]
Loss Contingencies [Line Items]
Beginning Balance	18
Settlements paid
Legal expenses incurred and/or paid
Ending Balance	18
Company's Responsibility at 10% [Member]
Loss Contingencies [Line Items]
Beginning Balance	4
Settlements paid
Legal expenses incurred and/or paid
Ending Balance	4
Reduction to Amount Owed to CVR Holders at 90% [Member]
Loss Contingencies [Line Items]
Beginning Balance	40
Settlements paid
Legal expenses incurred and/or paid	1
Ending Balance	$ 41