Derivative Instruments - Fair Value of Derivative Instruments Balance Sheet Classification (Details) - Not Designated as Hedging Instrument - USD ($)
$ in Thousands |
Dec. 31, 2018 |
Dec. 31, 2017 |
| Derivative Asset, Fair Value, Amount Not Offset Against Collateral [Abstract] |
|
|
| Gross Fair Value Asset/Liability Amounts |
|
$ 1,382
|
| Gross Amounts Offset |
|
(287)
|
| Net Recognized Fair Value Assets/Liabilities |
|
1,095
|
| Current assets - Derivative instruments |
|
|
| Derivative Asset, Fair Value, Amount Not Offset Against Collateral [Abstract] |
|
|
| Gross Fair Value Asset/Liability Amounts |
$ 7,708
|
720
|
| Gross Amounts Offset |
(6,076)
|
(287)
|
| Net Recognized Fair Value Assets/Liabilities |
1,632
|
433
|
| Noncurrent assets - Derivative instruments |
|
|
| Derivative Asset, Fair Value, Amount Not Offset Against Collateral [Abstract] |
|
|
| Gross Fair Value Asset/Liability Amounts |
|
662
|
| Gross Amounts Offset |
|
0
|
| Net Recognized Fair Value Assets/Liabilities |
|
662
|
| Current liabilities - Derivative instruments |
|
|
| Derivative Liability, Fair Value, Amount Not Offset Against Collateral [Abstract] |
|
|
| Gross Fair Value Asset/Liability Amounts |
12,127
|
527
|
| Gross Amounts Offset |
(6,076)
|
(287)
|
| Net Recognized Fair Value Assets/Liabilities |
$ 6,051
|
$ 240
|