Derivative Financial Instruments (Derivatives And Hedging-Overall-Subsequent Measurement) (Details) - Not Designated as Hedging Instrument [Member] - USD ($) $ in Thousands |
3 Months Ended | 6 Months Ended | ||
|---|---|---|---|---|
Jun. 30, 2020 |
Jun. 30, 2019 |
Jun. 30, 2020 |
Jun. 30, 2019 |
|
| Derivative Instruments, Gain (Loss) [Line Items] | ||||
| Derivative, Gain (Loss) on Derivative, Net | $ (23,772) | $ (17,254) | $ 93,171 | $ (67,964) |
| Commodity Contract [Member] | Sales [Member] | ||||
| Derivative Instruments, Gain (Loss) [Line Items] | ||||
| Derivative, Gain (Loss) on Derivative, Net | (26,755) | (4,619) | 97,014 | (59,130) |
| Commodity Contract [Member] | Cost of Sales [Member] | ||||
| Derivative Instruments, Gain (Loss) [Line Items] | ||||
| Derivative, Gain (Loss) on Derivative, Net | (417) | (6,148) | (4,344) | (3,875) |
| Energy Related Derivative [Member] | Other Operating Income (Expense) [Member] | ||||
| Derivative Instruments, Gain (Loss) [Line Items] | ||||
| Derivative, Gain (Loss) on Derivative, Net | $ 3,400 | $ (6,487) | $ 501 | $ (4,959) |