TAX EFFECT ALLOCATED TO EACH COMPONENT OF OTHER COMPREHENSIVE INCOME (LOSS) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Statement of Income and Comprehensive Income
Amortization of net losses of pension and postretirement benefit plans	$ (2,011)	$ (2,204)	$ (4,022)	$ (4,407)
Unrealized holding gains on debt securities arising during the period	1,524	(12,989)	(63,817)	(21,449)
Unrealized net losses on cash flow hedges	187	427	1,300	672
Reclassification adjustment for net losses included in net income	(736)	(334)	(1,222)	(720)
Income tax expenses	$ (1,036)	$ (15,100)	$ (67,761)	$ (25,904)

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) of reclassification adjustment from accumulated other comprehensive income (loss) for gain (loss) of defined benefit plan.

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Amount of tax expense (benefit) allocated to other comprehensive income (loss) attributable to parent entity.

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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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Amount of tax expense (benefit) before reclassification adjustments of unrealized holding gain (loss) on available-for-sale securities.

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