Business Segments Information - Schedule of Reconciliation of Segment Adjusted EBITDA to Net Income (Parenthetical) (Detail) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended
	Jun. 30, 2019	Jun. 30, 2018
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Common stock dividend per share	$ 1.09	$ 0.08
Additional stock-based compensation expense	$ 1,841	$ 1,559
Cost of Goods Sold - ESOP special dividend compensation and Selling, General and Administrative Expenses [Member]
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Additional stock-based compensation expense	$ 246,800
Special Dividend [Member]
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Common stock dividend per share	$ 1.00
Quarterly Dividend [Member]
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Common stock dividend per share	$ 0.09