Commitments and Contingent Liabilities Commitments and Contingent Liabilities (Maximum Potential Obligation) (Details) $ in Millions	Jun. 30, 2015 USD ($)
Commitment Period Two Thousand Twenty Three [Member]
Other Commitments [Line Items]
Guarantor Obligations, Maximum Exposure, Undiscounted	$ 500
Commitment Period Two Thousand Thirty Three [Member]
Other Commitments [Line Items]
Guarantor Obligations, Maximum Exposure, Undiscounted	950
Commitment Period Two Thousand Thirty Four [Member]
Other Commitments [Line Items]
Guarantor Obligations, Maximum Exposure, Undiscounted	3,000
Commitment Period Two Thousand Thirty Five [Member]
Other Commitments [Line Items]
Guarantor Obligations, Maximum Exposure, Undiscounted	500
Commitment Period Two Thousand Thirty Six [Member]
Other Commitments [Line Items]
Guarantor Obligations, Maximum Exposure, Undiscounted	$ 1,432