Commitments and Contingent Liabilities Guarantee Narrative (Details) - USD ($) $ in Millions		9 Months Ended
		Sep. 30, 2018	Dec. 31, 2017
Guarantor Obligations [Line Items]
Guarantee Obligations		$ 282	$ 297
Customer Guarantee, Bank Borrowings [Member]
Guarantor Obligations [Line Items]
Guarantee Obligations	[1]	$ 75
Guarantor Obligations, Liquidation Proceeds, Percentage		22.00%

[1] Existing guarantees for select customers, as part of contractual agreements. The terms of the guarantees are equivalent to the terms of the customer loans that are primarily made to finance customer invoices. Of the total maximum future payments, $72 million