Long-term Financing and Sales of Receivables (Narrative) (Details) - USD ($) $ in Millions	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Accounts, Notes, Loans and Financing Receivable [Line Items]
Interest income recognized on long-term receivables	$ 2	$ 2	$ 1
Commitments to provide long-term financing	125	112
Servicing obligations for long-term receivables	774	668
Financing receivables over 90 days past due	2	1
Commercial loans and leases secured
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivables over 90 days past due	$ 2	$ 1