Income Taxes - Additional Information (Detail) - USD ($) $ in Thousands, shares in Millions			3 Months Ended
	Jul. 31, 2019	Jun. 14, 2019	Jun. 30, 2020	Jun. 30, 2019
Income Taxes [Line Items]
Effective income tax rate			27.80%	(10.90%)
Discrete income tax expense				$ 60,700
Additional stock-based compensation expense			$ 5,599	$ 1,841
IWT [Member]
Income Taxes [Line Items]
Total purchase price	$ 132,400
Purchase price related to step up of GAAP basis for fair market valuations	82,300
Deferred tax liabilities acquired	50,100
Business combination, acquired federal net operating loss	24,000
IWT [Member] | Intangible Assets [Member]
Income Taxes [Line Items]
Purchase price related to step up of GAAP basis for fair market valuations	$ 80,200
Employee Stock Ownership Plan (ESOP) [Member]
Income Taxes [Line Items]
Non-deductible stock appreciation and deductible dividends			$ 242,900
Effective tax rate reduced by discrete event			29.60%
Employee Stock Ownership Plan (ESOP) [Member] | Special Dividend [Member]
Income Taxes [Line Items]
Shares allocated from the ESOP from discrete event		11.6
Additional stock-based compensation expense		$ 246,800