EMPLOYEE BENEFIT PLANS - Narrative (Details) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2019	Jan. 01, 2021
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined contribution plan, employer discretionary contribution amount	$ 8,576	$ 6,855	$ 7,097
Postemployment benefits liability	1,678	1,833
Non-service cost components of net periodic benefit cost (credit)	$ (907)	(1,559)	(3,148)
Change in discount rate	10.00%
Tax benefit for amortization of pension cost	$ 270	878	221
Completion period of service	1 year
Maximum compensation of proportion	$ 290
Employee stock ownership plan (ESOP), compensation expense	3,678	2,878	$ 2,629
Employee stock ownership plan (ESOP), deferred shares, fair value	45,571	40,217
Clopay AMES Plan
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Adjusted funding target attainment percent				98.70%
Adjusted funding target attainment percent, threshold				80.00%
Defined benefit plans, estimated future employer catch up contributions in next fiscal year	198
Other Postretirement Benefits Plan
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Accumulated other comprehensive income (loss), pension and other postretirement benefit plans, net of tax	(118)	(196)
Pension and other postretirement benefit expense	35	46
Supplemental Employee Retirement Plan
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Accumulated other comprehensive income (loss), pension and other postretirement benefit plans, net of tax	(6,053)	(6,083)
Defined benefit plans, estimated future employer contributions in next fiscal year	1,884
Pension Plan
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Accumulated other comprehensive income (loss), pension and other postretirement benefit plans, net of tax	(30,254)	$ (48,716)
Defined benefit plans, estimated future employer contributions in next fiscal year	$ 953