Derivatives (Details 5) (USD $) In Millions, unless otherwise specified	Jun. 30, 2014	Dec. 31, 2013
Offsetting of Financial Assets under Master Netting Agreements with Derivative Counterparties
Gross Amounts of Derivative Assets Presented in the Consolidated Balance Sheet	$ 70	$ 84
Net Amounts of Derivative Assets	37	33
Derivatives Subject to Master Netting Agreements
Offsetting of Financial Assets under Master Netting Agreements with Derivative Counterparties
Gross Amounts of Derivative Assets Presented in the Consolidated Balance Sheet	69	83
Gross Amount of Eligible Offsetting Recognized Derivative Liabilities	33	51
Cash Collateral Received	0	0
Net Amounts of Derivative Assets	36	32
Derivatives Not Subject to Master Netting Agreements
Offsetting of Financial Assets under Master Netting Agreements with Derivative Counterparties
Gross Amounts of Derivative Assets Presented in the Consolidated Balance Sheet	1	1
Net Amounts of Derivative Assets	$ 1	$ 1