Fair Value Measurements (Commercial Aerospace Financing Commitments) (Details) - USD ($) $ in Billions |
Sep. 30, 2016 |
Dec. 31, 2015 |
|---|---|---|
| Commercial Aerospace [Member] | ||
| Accounts, Notes, Loans and Financing Receivable [Line Items] | ||
| Financing and other contractual commitments | $ 14.5 | $ 14.6 |