Leases And Commitments (Narrative) (Details) - USD ($) $ in Millions |
12 Months Ended | ||
---|---|---|---|
Dec. 31, 2017 |
Dec. 31, 2016 |
Dec. 31, 2015 |
|
Rent expense for operating leases | $ 249 | $ 220 | $ 209 |
Maximum | |||
Lessee leasing arrangements, operating leases, term of contract (in years) | 20 years | ||
Minimum | |||
Warranty period terms minimum | 90 days |