Net Income Per Share and Stockholders' Equity - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Feb. 28, 2017
Equity Class Of Treasury Stock [Line Items]
Stock repurchase program amount authorized			$ 50,000
Cash dividend declared	$ 0.09
Dividend payment	$ 81,600
Additional stock-based compensation expense	1,841	$ 1,559
Cost of Goods Sold - ESOP special dividend compensation and Selling, General and Administrative Expenses [Member]
Equity Class Of Treasury Stock [Line Items]
Additional stock-based compensation expense	$ 246,800
ESOP [Member]
Equity Class Of Treasury Stock [Line Items]
Number of redeemable convertible preferred stock allocated to ESOP participants	11,600
Amount of dividend from unallocated redeemable convertible preferred stock held in the ESOP trust to repay ESOP loan	$ 12,000
Special Dividend [Member]
Equity Class Of Treasury Stock [Line Items]
Cash dividend declared	$ 1.00
Dividend payable date	Jun. 14, 2019
Dividend payable, date of record	Jun. 03, 2019
Special Dividend [Member] | ESOP [Member]
Equity Class Of Treasury Stock [Line Items]
Dividend payable date	Jun. 14, 2019
Additional stock-based compensation expense	$ 246,800
Common Stock [Member]
Equity Class Of Treasury Stock [Line Items]
Common stock repurchases, Shares	0	0
Stock repurchase program amount authorized	$ 42,100