Components of Net Periodic Benefit Cost (Details) - USD ($)	3 Months Ended			6 Months Ended		12 Months Ended
	Apr. 30, 2020	Jan. 31, 2020	Apr. 30, 2019	Apr. 30, 2020	Apr. 30, 2019	Oct. 31, 2020
Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Interest cost	$ 676,000		$ 841,000	$ 1,351,000	$ 1,682,000
Expected return on plan assets	(831,000)		(835,000)	(1,662,000)	(1,670,000)
Defined Benefit Plan, Amortization of Gain (Loss)	374,000		286,000	748,000	573,000
Net periodic (benefit) cost	219,000		292,000	437,000	585,000
Pension Contributions		$ 219,000
Other Postretirement Benefits Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Interest cost	2,000		3,000	4,000	6,000
Expected return on plan assets	0		0	0	0
Defined Benefit Plan, Amortization of Gain (Loss)	2,000		2,000	4,000	3,000
Net periodic (benefit) cost	$ 4,000		$ 5,000	$ 8,000	$ 9,000
Forecast [Member] | Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Pension Contributions						$ 897,000