Derivative Financial Instruments (Derivatives And Hedging-Overall-Subsequent Measurement) (Details) - Not Designated as Hedging Instrument [Member] - USD ($) $ in Thousands |
3 Months Ended | |
|---|---|---|
Mar. 31, 2019 |
Mar. 31, 2018 |
|
| Derivative Instruments, Gain (Loss) [Line Items] | ||
| Derivative, Gain (Loss) on Derivative, Net | $ (52,238) | $ (11,319) |
| Commodity Contract [Member] | Sales [Member] | ||
| Derivative Instruments, Gain (Loss) [Line Items] | ||
| Derivative, Gain (Loss) on Derivative, Net | (54,511) | (7,375) |
| Commodity Contract [Member] | Cost of Sales [Member] | ||
| Derivative Instruments, Gain (Loss) [Line Items] | ||
| Derivative, Gain (Loss) on Derivative, Net | $ 2,273 | $ (3,944) |