Consolidated Statements of Comprehensive Income (Loss) (Parenthetical) - USD ($) $ in Thousands	12 Months Ended
Mar. 31, 2020	Mar. 31, 2019	Mar. 31, 2018
Change in pension liability and postretirement obligations, tax	$ 8,010	$ 2,097	$ (5,205)
Change in derivatives qualifying as hedges, tax	(565)	469	(1,519)
Unrealized holding gain arising during the period, tax	0	0	(124)
Pension Plans
Change in pension liability and postretirement obligations, tax	8,062	2,242	(4,981)
Postretirement Benefit Plans
Change in pension liability and postretirement obligations, tax	(35)	(126)	(153)
Defined Benefit Postretirement Life Insurance
Change in pension liability and postretirement obligations, tax	$ (17)	$ (18)	$ (70)

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).

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section 45
-Paragraph 10A
-Subparagraph (d)
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-Name Accounting Standards Codification
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Amount, after reclassification adjustment, of tax (expense) benefit for (increase) decrease in accumulated other comprehensive income of defined benefit plan.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section 45
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Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
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-URI http://asc.fasb.org/extlink&oid=118930883&loc=SL7669646-108580

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-Publisher FASB
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-SubTopic 10
-Section 45
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