Consolidated Statements of Comprehensive Income - Parenthetical - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Reclassification adjustment for loss on derivative instruments included in net income, tax	$ 36	$ 55	$ (177)	$ 164
Amortization of postretirement liability losses included in net periodic benefit cost, tax	95	142	284	442
Foreign currency translation adjustments recognized during the period, tax	0	0	0	(14)
Reclassification of foreign currency translation adjustment	0	0	0	75
Net unrealized gain (loss) on available-for-sale investments arising during the period, tax	3	(13)	35	(52)
Reclassification adjustment for (gain) loss on available-for-sale investments included in net income, tax	$ (1)	$ 9	$ 10	$ 26

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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