Derivative Financial Instruments - Hedges (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Fair values of derivative financial instruments
Cash flow hedge, Gain (loss) recognized in other comprehensive income	$ 5,400		$ 5,400
Cash flow hedge, Gain (loss) reclassified from other comprehensive income	200		200
Cash flow hedge, Gain (loss) to be reclassified			3,400
Fair Value Hedge \| Futures contracts \| Cost of sales
Fair values of derivative financial instruments
Fair value hedge, Amount of Gain (Loss) Recognized in Income on Derivatives	(46,637)	$ 5,899	1,698	$ 1,238
Fair Value Hedge \| Inventories \| Cost of sales
Fair values of derivative financial instruments
Fair value hedge, Amount of Gain (Loss) Recognized in Income on Hedged Items	$ 44,025	$ (8,036)	$ (6,157)	$ (2,985)

The estimated net amount of existing gains or losses on cash flow hedges at the reporting date expected to be reclassified to earnings within the next 12 months.

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Amount of gain (loss) from the increase (decrease) in fair value of derivative and nonderivative instruments designated as fair value hedging instruments recognized in the income statement.

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Amount of the increase (decrease) in fair value of the hedged item in a fair value hedge recognized in the income statement.

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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Amount, after tax and before reclassification, of gain (loss) from derivative instrument designated and qualifying as cash flow hedge included in assessment of hedge effectiveness.

+ References

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Amount, after tax, of reclassification of gain (loss) from accumulated other comprehensive income (AOCI) for derivative instrument designated and qualifying as cash flow hedge included in assessment of hedge effectiveness.

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