Stock-Based Compensation	3 Months Ended
	Jul. 31, 2020
Share-based Payment Arrangement [Abstract]
Stock-Based Compensation	Stock-Based CompensationDuring the three months ended July 31, 2020 and 2019, we granted options for 535,000 and 47,000 shares of Class A common stock, respectively. The fair value of each option award is estimated on the date of grant using the Black-Scholes option pricing model. The forfeiture rates are estimated using historical data. We recorded stock option compensation cost of approximately $0.5 million and $0.4 million and income tax benefits of approximately $234,000 and $62,000 from option exercises during the three months ended July 31, 2020 and 2019, respectively. We record stock-based compensation expense on a straight-line basis over the vesting period directly to additional paid-in capital.During the three months ended July 31, 2020 and 2019, we issued 230,747 and 151,500 shares of Class A common stock, respectively, resulting from the exercise of stock options. The total intrinsic value of options exercised during the three months ended July 31, 2020 and 2019 based on market value at the exercise dates was approximately $1.4 million and $0.6 million, respectively. As of July 31, 2020, unrecognized compensation cost related to unvested stock option awards approximated $6.8 million, which we expect to recognize over a weighted average period of 1.94 years.