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Deferred Compensation And Retirement Plans - Reconciliation Of Benefit Obligation (Detail) - USD ($) $ in Thousands | 12 Months Ended
--- | ---
Apr. 30, 2019 | Apr. 30, 2018 | Apr. 30, 2017
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Total benefit obligation |  | $ 275,453 | $ 249,720 |
Deferred Compensation Plan |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Benefit obligation, beginning of year |  | 126,494 | 121,042 |
Service cost |  | 17,281 | 11,373 | $ 5,402
Interest cost |  | 5,044 | 3,787 | 3,925
Actuarial loss (gain) |  | 7,803 | (1,574) |
Administrative expenses paid |  | (272) | (166) |
Benefits paid from plan assets |  | (1,877) | (1,833) |
Benefits paid from cash |  | (6,104) | (6,135) |
Benefit obligation, end of year |  | 148,369 | 126,494 | 121,042
Fair value of plan assets, beginning of year |  | 26,090 | 25,446 |
Actual return on plan assets |  | 1,160 | 2,425 |
Benefits paid from plan assets |  | (1,877) | (1,833) |
Administrative expenses paid |  | (272) | (166) |
Employer contributions |  | 30 | 218 |
Fair value of plan assets, end of year |  | 25,131 | 26,090 | 25,446
Funded status and balance, end of year | [1] | (123,238) | (100,404) |
Current liability |  | 8,331 | 6,496 |
Non-current liability |  | 114,907 | 93,908 |
Total benefit obligation |  | $ 123,238 | $ 100,404 |
Plan assets weighted average allocation |  | 100.00% | 100.00% |
Deferred Compensation Plan | Debt Securities |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Plan assets weighted average allocation |  | 54.00% | 55.00% |
Deferred Compensation Plan | Equity Securities |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Plan assets weighted average allocation |  | 45.00% | 44.00% |
Deferred Compensation Plan | Other securities |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Plan assets weighted average allocation |  | 1.00% | 1.00% |
Executive Capital Accumulation Plan |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Benefit obligation, beginning of year |  | $ 128,430 | $ 111,584 |
Employee contributions |  | 4,852 | 5,036 |
Amortization of employer contributions |  | 9,573 | 12,175 |
Gain on investment |  | 8,697 | 11,095 |
Benefits paid from cash |  | (20,891) | (11,923) |
Exchange rate fluctuations |  | (500) | 463 |
Benefit obligation, end of year |  | 130,161 | 128,430 | $ 111,584
Current liability |  | 8,844 | 14,827 |
Non-current liability |  | 121,317 | 113,603 |
Total benefit obligation |  | $ 130,161 | $ 128,430 |
[1] | The Company purchased COLI contracts insuring the lives of certain employees eligible to participate in the deferred compensation and pension plans as a means of funding benefits under such plans. As of April 30, 2019 and 2018, the Company held contracts with gross CSV of $219.2 million and $186.8 million, offset by outstanding policy loans of $93.2 million and $66.7 million, respectively

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