Consolidated Statements of Changes in Stockholders' Equity (Parenthetical) - USD ($) $ in Thousands	12 Months Ended
Mar. 31, 2020	Mar. 31, 2019	Mar. 31, 2018
Statement of Stockholders' Equity [Abstract]
Dividends per common share	$ 0.70	$ 0.70	$ 0.70
Pension funded status adjustment, tax benefit (expense)	$ 468	$ (120)	$ (2,071)
Net unrealized gain (loss) on derivative instruments, tax (benefit) expense	$ (1,793)	$ 1,006	$ 808

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

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

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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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