LONG-TERM DEBT - Narrative (Details) £ in Thousands, $ in Thousands, $ in Thousands				1 Months Ended	3 Months Ended	6 Months Ended	12 Months Ended
	Jun. 30, 2023 USD ($)	Jun. 30, 2023 GBP (£)	Jan. 24, 2022 USD ($)	Nov. 30, 2012	Mar. 31, 2024 USD ($)	Mar. 31, 2024 USD ($)	Sep. 30, 2023 USD ($)	Sep. 30, 2022 USD ($)	Sep. 30, 2020 USD ($)	Mar. 31, 2024 CAD ($)	Mar. 31, 2024 AUD ($)	Sep. 28, 2023 USD ($)	Aug. 01, 2023 USD ($)	Jul. 31, 2023 USD ($)	Sep. 30, 2022 AUD ($)	Jul. 31, 2018 GBP (£)
Debt Instrument [Line Items]
Weighted average discount								91.82%							91.82%
Debt outstanding					$ 1,603,554,000	$ 1,603,554,000	$ 1,489,812,000
Revolving Credit Facility | Ames UK
Debt Instrument [Line Items]
Face amount | £																£ 5,000
Debt outstanding														$ 0
Long-term line of credit, revolver outstanding balance					0	0
Revolver due 2028
Debt Instrument [Line Items]
Maximum borrowing capacity													$ 500,000,000	400,000,000
Line of credit facility, incremental minimum borrowing amount													500,000,000	375,000,000
Outstanding standby letters of credit					12,962,000	12,962,000
Remaining borrowing capacity					$ 317,538,000	$ 317,538,000
Maximum percentage of equity interest of subsidiaries borrowings guaranteed					65.00%
Revolver due 2028 | Letter of Credit Subfacility
Debt Instrument [Line Items]
Maximum borrowing capacity													125,000,000	$ 100,000,000
Revolver due 2028 | Multicurrency Subfacility
Debt Instrument [Line Items]
Maximum borrowing capacity													$ 200,000,000
Revolver Due 2025, SOFR Loan
Debt Instrument [Line Items]
Debt instrument, interest rate, effective percentage					7.43%	7.43%				7.43%	7.43%
Revolver Due 2025, SOFR Loan | Secured Overnight Financing Rate
Debt Instrument [Line Items]
Basis spread on variable rate						2.00%
Revolver Due 2025, SONIA Loan
Debt Instrument [Line Items]
Debt instrument, interest rate, effective percentage					7.22%	7.22%				7.22%	7.22%
Revolver Due 2025, SONIA Loan | SONIA
Debt Instrument [Line Items]
Basis spread on variable rate						2.00%
Revolver Due 2025, Base Rate Loan
Debt Instrument [Line Items]
Debt instrument, interest rate, effective percentage					9.50%	9.50%				9.50%	9.50%
Revolver Due 2025, Base Rate Loan | Base Rate
Debt Instrument [Line Items]
Basis spread on variable rate						1.00%
Term Loan | Ames UK
Debt Instrument [Line Items]
Face amount | £																14,000
Repayments of debt	$ 9,543,000	£ 7,525
Mortgages | Ames UK
Debt Instrument [Line Items]
Face amount | £																£ 4,000
Receivables Purchase Facility | Northcote Holdings Pty. Ltd
Debt Instrument [Line Items]
Maximum borrowing capacity															$ 15,000
Debt instrument, interest rate, effective percentage					5.55%	5.55%				5.55%	5.55%
Remaining borrowing capacity					$ 19,575,000	$ 19,575,000					$ 30,000
Long-term line of credit					$ 0	$ 0
Receivables Purchase Facility | Bank Bill Swap Rate | Northcote Holdings Pty. Ltd
Debt Instrument [Line Items]
Basis spread on variable rate						1.25%
Senior notes due 2028
Debt Instrument [Line Items]
Face amount									$ 1,000,000,000
Debt instrument, interest rate, stated percentage					5.75%	5.75%	5.75%		5.75%	5.75%	5.75%
Capitalized debt issuance costs									$ 16,448,000
Repurchased face amount								$ 25,225,000,000
Repurchase amount								23,161,000,000
Debt outstanding					$ 974,775,000	$ 974,775,000	$ 974,775,000
Debt issuance fees and expenses, net					7,910,000	7,910,000
Senior notes due 2028 | Fair Value, Inputs, Level 1
Debt Instrument [Line Items]
Senior note, fair value disclosure					950,406,000	950,406,000
Senior notes due 2022
Debt Instrument [Line Items]
Repayments of debt									$ 1,000,000,000
Debt instrument, interest rate, stated percentage									5.25%
Term Loan | Term Loan B due 2029
Debt Instrument [Line Items]
Face amount			$ 800,000,000
Capitalized debt issuance costs			$ 15,466,000
Debt issuance fees and expenses, net					$ 6,378,000	$ 6,378,000
Debt instrument, interest rate, effective percentage					7.70%	7.70%				7.70%	7.70%
Secured overnight financing rate floor			0.50%
Debt instrument, issuance price (in percentage)			99.75%
Principal payments					$ 2,000,000
Debt redeemed							25,000,000	300,000,000
Gain (loss) on extinguishment of debt							(437,000)	(6,296,000)
Write off of deferred debt issuance cost, underwriting and other fees							386,000	5,575,000
Write off of deferred debt issuance cost, original issuer discount							51,000	$ 721,000
Term Loan | Term Loan B due 2029 | Secured Overnight Financing Rate
Debt Instrument [Line Items]
Basis spread on variable rate			2.25%
Term Loan B due 2029
Debt Instrument [Line Items]
Debt outstanding					459,000,000	$ 459,000,000	$ 463,000,000
Term Loan B due 2029 | Fair Value, Inputs, Level 1
Debt Instrument [Line Items]
Senior note, fair value disclosure					459,574,000	459,574,000
Non US lines of credit
Debt Instrument [Line Items]
Maximum borrowing capacity					$ 11,039,000	$ 11,039,000				$ 15,000
Basis spread on variable rate				1.30%
Non US lines of credit | CORRA
Debt Instrument [Line Items]
Interest rate at period end					6.30%	6.30%				6.30%	6.30%
Non US lines of credit | Canadian Bankers Acceptance Rate
Debt Instrument [Line Items]
Interest rate at period end					6.35%	6.35%				6.35%	6.35%
Mortgages | Ames UK
Debt Instrument [Line Items]
Repayments of debt	$ 3,108,000	£ 2,451
Finance lease - real estate | Ocala, Florida
Debt Instrument [Line Items]
Payment to acquire leased property												$ 23,207,000
Lessee, finance Lease, discount rate												5.60%