Benefit Plans	12 Months Ended
Apr. 30, 2017
Retirement Benefits [Abstract]
Benefit Plans	BENEFIT PLANS 401(k) plan The Company provides employees with a defined contribution 401(k) plan. The 401(k) plan covers all employees who meet minimum age and service requirements. The Company contributions consist of matching amounts in Company stock and are allocated based on employee contributions. Contributions to the 401(k) plan were $8,181, $6,560, and $5,852 for the years ended April 30, 2017, 2016, and 2015, respectively. On April 30, 2017 and 2016, 1,401,764 and 1,419,841 shares of common stock, respectively, were held by the trustee of the 401(k) plan in trust for distribution to eligible participants upon death, disability, retirement, or termination of employment. Shares held by the 401(k) plan are treated as outstanding in the computation of net income per common share. Supplemental executive retirement plan The Company has a nonqualified supplemental executive retirement plan (SERP) for two of its executive officers, one of whom retired April 30, 2003 and the other on April 30, 2008. The SERP provides for the Company to pay annual retirement benefits, up to 50% of base compensation until death of the officer. If death occurs within twenty years of retirement, the benefits become payable to the officer’s spouse (at a reduced level) until the spouse’s death or twenty years from the date of the officer’s retirement, whichever comes first. The Company has accrued the deferred compensation over the term of employment. The amounts accrued at April 30, 2017 and 2016, respectively, were $4,737 and $5,230. The discount rates used were 4.0% and 3.8%, respectively, at April 30, 2017 and 2016. The amount expensed in fiscal 2017 was $131 and the Company expects to pay $625 per year for each of the next five years. Expense incurred in fiscal 2016 and fiscal 2015 was $230 and $326, respectively. Other post-employment benefits The Company also has severance and/or deferred compensation agreements with three other former employees. The amounts accrued at April 30, 2017 and 2016 were $3,825 and $4,043, respectively. The Company expects to pay $507, $457, $432, $432 and $432 the next five years under the agreements. The expense incurred in fiscal 2017, 2016 and 2015 was $370, $238, and $219 respectively.

BENEFIT PLANS

401(k) plan The Company provides employees with a defined contribution 401(k) plan. The 401(k) plan covers all employees who meet minimum age and service requirements. The Company contributions consist of matching amounts in Company stock and are allocated based on employee contributions. Contributions to the 401(k) plan were $8,181, $6,560, and $5,852 for the years ended April 30, 2017, 2016, and 2015, respectively.

On April 30, 2017 and 2016, 1,401,764 and 1,419,841 shares of common stock, respectively, were held by the trustee of the 401(k) plan in trust for distribution to eligible participants upon death, disability, retirement, or termination of employment. Shares held by the 401(k) plan are treated as outstanding in the computation of net income per common share.

Supplemental executive retirement plan The Company has a nonqualified supplemental executive retirement plan (SERP) for two of its executive officers, one of whom retired April 30, 2003 and the other on April 30, 2008. The SERP provides for the Company to pay annual retirement benefits, up to 50% of base compensation until death of the officer. If death occurs within twenty years of retirement, the benefits become payable to the officer’s spouse (at a reduced level) until the spouse’s death or twenty years from the date of the officer’s retirement, whichever comes first. The Company has accrued the deferred compensation over the term of employment. The amounts accrued at April 30, 2017 and 2016, respectively, were $4,737 and $5,230. The discount rates used were 4.0% and 3.8%, respectively, at April 30, 2017 and 2016. The amount expensed in fiscal 2017 was $131 and the Company expects to pay $625 per year for each of the next five years. Expense incurred in fiscal 2016 and fiscal 2015 was $230 and $326, respectively.

Other post-employment benefits The Company also has severance and/or deferred compensation agreements with three other former employees. The amounts accrued at April 30, 2017 and 2016 were $3,825 and $4,043, respectively. The Company expects to pay $507, $457, $432, $432 and $432 the next five years under the agreements. The expense incurred in fiscal 2017, 2016 and 2015 was $370, $238, and $219 respectively.