CONSOLIDATED STATEMENT OF SHAREHOLDERS EQUITY (Parenthetical) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Statement of Stockholders' Equity [Abstract]
Tax effect of gain (losses) on derivatives qualifying as hedges	$ 709	$ (348)	$ 1,007	$ 39
Tax effect of pension liability and postretirement adjustment	$ (1,031)	$ (1,937)	$ (3,218)	$ (3,038)
Cash dividends declared, per share	$ 0.77	$ 0.75	$ 2.27	$ 2.21

Aggregate dividends declared during the period for each share of common stock outstanding.

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

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