|
Derivatives (Effects Of Derivatives On Measures Of Financial Performance) (Details) (USD $)
In Thousands, unless otherwise specified
|
3 Months Ended |
|
Mar. 31, 2015
|
Mar. 31, 2014
|
| Designated as Hedging Instrument [Member] |
|
|
| Derivative Instruments, Gain (Loss) [Line Items] |
|
|
| Gain (Loss) Recognized in Other Comprehensive Income(Effective Portion) |
$ 5,527 |
$ 74 |
| Gains (Losses) Reclassified from Other Comprehensive Income into Income (Effective Portion) |
481 |
302 |
| Designated as Hedging Instrument [Member] | Coal Contract [Member] | Coal sales [Member] |
|
|
| Derivative Instruments, Gain (Loss) [Line Items] |
|
|
| Gain (Loss) Recognized in Other Comprehensive Income(Effective Portion) |
10,265 |
(515) |
| Designated as Hedging Instrument [Member] | Coal Contract [Member] | Coal sales [Member] | Sales Revenue, Net [Member] |
|
|
| Derivative Instruments, Gain (Loss) [Line Items] |
|
|
| Gains (Losses) Reclassified from Other Comprehensive Income into Income (Effective Portion) |
882 |
706 |
| Designated as Hedging Instrument [Member] | Coal Contract [Member] | Coal purchases [Member] |
|
|
| Derivative Instruments, Gain (Loss) [Line Items] |
|
|
| Gain (Loss) Recognized in Other Comprehensive Income(Effective Portion) |
(4,738) |
589 |
| Designated as Hedging Instrument [Member] | Coal Contract [Member] | Coal purchases [Member] | Cost of Sales [Member] |
|
|
| Derivative Instruments, Gain (Loss) [Line Items] |
|
|
| Gains (Losses) Reclassified from Other Comprehensive Income into Income (Effective Portion) |
(401) |
(404) |
| Not Designated as Hedging Instrument [Member] | Coal Contract [Member] | Change in Fair Value of Coal Derivatives and Coal Trading Activity, Net [Member] |
|
|
| Derivative Instruments, Gain (Loss) [Line Items] |
|
|
| Unrealized Gain (Loss) on Derivatives |
(411) |
(1,302) |
| Not Designated as Hedging Instrument [Member] | Coal Contract [Member] | Other Operating Income (Expense) [Member] |
|
|
| Derivative Instruments, Gain (Loss) [Line Items] |
|
|
| Realized Gain (Loss) on Derivatives |
1,091 |
2,879 |
| Not Designated as Hedging Instrument [Member] | Natural Gas [Member] | Change in Fair Value of Coal Derivatives and Coal Trading Activity, Net [Member] |
|
|
| Derivative Instruments, Gain (Loss) [Line Items] |
|
|
| Unrealized Gain (Loss) on Derivatives |
159 |
8 |
| Not Designated as Hedging Instrument [Member] | Heating Oil-Diesel Purchases [Member] | Other Operating Income (Expense) [Member] |
|
|
| Derivative Instruments, Gain (Loss) [Line Items] |
|
|
| Heating oil realized and unrealized gains and losses |
(2,365) |
(2,963) |
| Not Designated as Hedging Instrument [Member] | Heating Oil-Fuel Surcharges [Member] | Other Operating Income (Expense) [Member] |
|
|
| Derivative Instruments, Gain (Loss) [Line Items] |
|
|
| Heating oil realized and unrealized gains and losses |
$ 0 |
$ (254) |