Commitments and Guarantees (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Unrecorded Unconditional Purchase Obligation [Line Items]
Other Commitment	$ 33
Long-term Contract for Purchase of Electric Power, Estimated Annual Cost	15
Other Commitment, Due in Second Year	11
Other Commitment, Due in Third Year	7
Operating Leases, Future Minimum Payments, Due in Three Years	$ 3
percentage of output	25.00%
Contractual Obligation	$ 2
Operating Leases, Rent Expense	10	$ 11	$ 9
Operating Leases, Future Minimum Payments Receivable, Current	4
Operating Leases, Future Minimum Payments Receivable, in Two Years	3
Future Minimum Sublease Rentals, Sale Leaseback Transactions, within Five Years	3
Operating Leases, Rent Expense, Sublease Rentals	3	$ 3	$ 3
Future Minimum Sublease Rentals, Sale Leaseback Transactions, within Three Years	$ 3