Contingencies (Impact of Legal Expenses Paid or Incurred to Date and Settlements Paid or Deemed Final) (Details) $ in Millions	9 Months Ended
	Sep. 30, 2016 USD ($)
Loss Contingencies [Line Items]
As of December 31, 2015	$ 58
Settlements paid	1
Legal expenses incurred and/or paid during the nine months ended September 30, 2016	2
As of September 30, 2016	61
Deductible [Member]
Loss Contingencies [Line Items]
As of December 31, 2015	18
As of September 30, 2016	18
CHS Responsibility at 10% [Member]
Loss Contingencies [Line Items]
As of December 31, 2015	4
As of September 30, 2016	4
Reduction to Amount Owed to CVR Holders at 90% [Member]
Loss Contingencies [Line Items]
As of December 31, 2015	36
Settlements paid	1
Legal expenses incurred and/or paid during the nine months ended September 30, 2016	2
As of September 30, 2016	$ 39