Employee Benefit Plans - Schedule of Effect of Twenty Five Basis-Point Change in Discount Rates (Details) $ in Thousands	12 Months Ended
	Mar. 31, 2021 USD ($)
Pension Plan [Member]
Defined Benefit Plans And Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined benefit plan, effect of a 25 basis point increase in discount rate, obligation	$ (52,031)	[1]
Defined benefit plan, effect of a 25 basis point increase in discount rate, net periodic benefit cost	586
Defined benefit plan, effect of a 25 basis point decrease in discount rate, obligation	54,288	[1]
Defined benefit plan, effect of a 25 basis point decrease in discount rate, net periodic benefit cost	(707)
Other postretirement [Member]
Defined Benefit Plans And Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined benefit plan, effect of a 25 basis point increase in discount rate, obligation	(33)
Defined benefit plan, effect of a 25 basis point increase in discount rate, net periodic benefit cost	4
Defined benefit plan, effect of a 25 basis point decrease in discount rate, obligation	34
Defined benefit plan, effect of a 25 basis point decrease in discount rate, net periodic benefit cost	$ 4

[1] Excludes impact to plan assets due to the LDI investment approach discussed above under "Plan Assets, Investment Policy and Strategy."