Derivative Instruments - Fair Value of Derivative Instruments Balance Sheet Classification (Details) - Not Designated as Hedging Instrument - USD ($) $ in Thousands |
Dec. 31, 2019 |
Dec. 31, 2018 |
|---|---|---|
| Current assets - Derivative instruments | ||
| Derivative Asset, Fair Value, Amount Not Offset Against Collateral [Abstract] | ||
| Gross Fair Value Asset/Liability Amounts | $ 7,708 | |
| Gross Amounts Offset | (6,076) | |
| Net Recognized Fair Value Assets/Liabilities | 1,632 | |
| Current liabilities - Derivative instruments | ||
| Derivative Liability, Fair Value, Amount Not Offset Against Collateral [Abstract] | ||
| Gross Fair Value Asset/Liability Amounts | $ 325 | 12,127 |
| Gross Amounts Offset | 0 | (6,076) |
| Net Recognized Fair Value Assets/Liabilities | $ 325 | $ 6,051 |