Consolidated Statements of Comprehensive Income (Parenthetical) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Statement Of Comprehensive Income [Abstract]
Net unrealized (loss) income on hedging derivatives, tax	$ 400	$ (3,100)	$ (300)
Reclassification adjustment for (gain) loss on settlement of hedging derivatives included in net earnings, tax effect	2,500	700	0
Foreign currency translation (loss) gain tax	0	0	0
Adjustment to early retiree medical plan, tax effect	(339)	(485)	514
Reclassification adjustment for gain on early retiree medical plan included in net earnings, tax effect	17	$ 49	$ (108)
Liquidation of equity method investment in foreign joint venture, tax	$ 0

Statement Of Comprehensive Income [Abstract]

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Amount of tax expense (benefit), before reclassification adjustments of gain (loss) on foreign currency translation adjustments, foreign currency transactions designated and effective as economic hedges of a net investment in a foreign entity and intra-entity foreign currency transactions that are of a long-term-investment nature.

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Amount of tax expense (benefit) of reclassification adjustment from accumulated other comprehensive income for translation gain (loss) realized upon the sale or liquidation of an investment in a foreign entity and foreign currency hedges that are designated and qualified as hedging instruments for hedges of the foreign currency exposure of a net investment in a foreign operation.

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Amount, after reclassification adjustment, of tax (expense) benefit for (increase) decrease in accumulated other comprehensive income of defined benefit plan.

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Amount of tax expense (benefit) of reclassification adjustment from accumulated other comprehensive income of accumulated gain (loss) realized from derivative instruments designated and qualifying as the effective portion of cash flow hedges and an entity's share of an equity investee's deferred hedging gain (loss).

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Amount of tax expense (benefit), before reclassification adjustments, related to increase (decrease) in accumulated gain (loss) from derivative instruments designated and qualifying as the effective portion of cash flow hedges and an entity's share of an equity investee's increase (decrease) in deferred hedging gain (loss).

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