LONG-TERM DEBT - Narrative (Details) $ in Thousands				1 Months Ended			12 Months Ended
	Mar. 13, 2019 USD ($)	Jun. 30, 2017 USD ($)	Jul. 31, 2016 AUD ($)	Jul. 31, 2018 GBP (£)	Jul. 31, 2016 AUD ($)	Nov. 30, 2012 CAD ($)	Sep. 30, 2021 USD ($) option	Sep. 30, 2021 AUD ($) option	Sep. 30, 2020 USD ($)	Sep. 30, 2019 USD ($)	Sep. 30, 2021 CAD ($)	Sep. 30, 2021 AUD ($)	Sep. 30, 2021 GBP (£)	Sep. 30, 2020 AUD ($)	Sep. 29, 2020 AUD ($)	Jun. 22, 2020 USD ($)	Feb. 19, 2020 USD ($)	Jan. 30, 2020 USD ($)	Jan. 29, 2020 USD ($)
Debt Instrument [Line Items]
Minimum payments under debt agreements for 2022							$ 16,724,000
Minimum payments under debt agreements for 2023							17,267,000
Minimum payments under debt engagement for 2024							1,888,000
Minimum payments under debt agreements for 2025							15,296,000
Minimum payments under debt agreements for 2026							1,892,000
Minimum payments under debt agreements thereafter							1,007,439,000
Long-term debt, gross							1,060,506,000		$ 1,064,422,000
Capitalized fees & expenses							15,138,000		17,821,000
Gain (loss) from debt extinguishment							0		(7,925,000)	$ 0
Line of credit facility, amount outstanding											$ 0
Outstanding debt							1,045,683,000		1,046,964,000
Debt instrument, basis spread on variable rate						1.30%
Revolver Due 2025
Debt Instrument [Line Items]
Line of credit facility, remaining borrowing capacity							370,927,000
Maximum borrowing capacity																		$ 400,000,000	$ 350,000,000
Term Loan | Northcote Holdings Pty. Ltd
Debt Instrument [Line Items]
Debt instrument, face amount			$ 29,625,000		$ 29,625,000
Line of credit facility, amount outstanding							$ 7,847,000					$ 10,875,000		$ 23,375,000	$ 18,375,000
Debt instrument, periodic payment, principal					1,250,000
Debt instrument, balloon payment			9,625,000		9,625,000
Debt instrument, interest rate at period end							2.01%				2.01%	2.01%	2.01%
Term loan balance increase								$ 5,000,000
Term Loan | Ames UK
Debt Instrument [Line Items]
Debt instrument, face amount | £				£ 14,000,000
Debt instrument, periodic payment, principal | £				438,000
Debt instrument, balloon payment | £				7,088,000
Revolving Credit Facility | Northcote Holdings Pty. Ltd
Debt Instrument [Line Items]
Line of credit facility, interest rate at period end							1.97%				1.97%	1.97%	1.97%
Maximum borrowing capacity			20,000,000		20,000,000
Revolving Credit Facility | Ames UK
Debt Instrument [Line Items]
Debt instrument, face amount | £				£ 5,000,000
Outstanding debt							$ 3,012,000						£ 2,234,000
Debt instrument, basis spread on variable rate				3.25%			3.35%	3.35%
Term and Mortgage Loan July 2018 | Ames UK
Debt Instrument [Line Items]
Outstanding debt							$ 17,837,000						£ 13,229,000
Letter of Credit Subfacility | Revolver Due 2025
Debt Instrument [Line Items]
Line of credit facility, current borrowing capacity																		100,000,000
Line of credit facility, additional borrowing capacity																		100,000,000
Line of credit facility, amount outstanding							$ 15,590,000
Multicurrency Subfacility | Revolver Due 2025
Debt Instrument [Line Items]
Line of credit facility, current borrowing capacity																		200,000,000
Margin Rate | Revolver Due 2025
Debt Instrument [Line Items]
Line of credit facility, interest rate during period							0.50%	0.50%
LIBOR Rate
Debt Instrument [Line Items]
Line of credit facility, interest rate during period							1.50%	1.50%
Receivables Purchase Facility | Northcote Holdings Pty. Ltd
Debt Instrument [Line Items]
Debt instrument, face amount			$ 10,000,000		$ 10,000,000
Outstanding debt												$ 15,000,000		$ 10,000,000
Debt instrument, basis spread on variable rate					1.35%
Debt instrument, interest rate at period end							1.41%				1.41%	1.41%	1.41%
Increase in the commitment of receivables purchase line								$ 5,000,000
Finance Lease - Real Estate
Debt Instrument [Line Items]
Long-term debt, gross							$ 14,594,000		17,218,000
Capitalized fees & expenses							4,000		30,000
Outstanding debt							14,590,000		17,188,000
Revolver Due 2025
Debt Instrument [Line Items]
Long-term debt, gross							13,483,000		12,858,000
Capitalized fees & expenses							$ 1,718,000		2,209,000
Line of credit facility, current borrowing capacity																		$ 400,000,000	$ 350,000,000
Maximum percentage of equity interest of subsidiaries borrowings guaranteed							65.00%	65.00%
Outstanding debt							$ 11,765,000		10,649,000
Senior Notes | Fair Value, Inputs, Level 1
Debt Instrument [Line Items]
Notes payable, fair value disclosure							1,060,000,000
Senior Notes | Senior Notes Due 2028
Debt Instrument [Line Items]
Debt instrument, face amount																$ 150,000,000	$ 850,000,000
Stated percentage																5.75%	5.75%
Issuance price, percentage																100.25%
Capitalized fees & expenses							16,448,000
Unamortized debt issuance expense							13,293,000
Senior Notes | Senior Notes Due 2022
Debt Instrument [Line Items]
Debt instrument, face amount																$ 1,000,000,000
Stated percentage																5.25%
Gain (loss) from debt extinguishment							(7,925,000)
Write off of deferred debt issuance cost							6,725,000
Tender offer net premium expense							607,000
Redemption interest expense							593,000
ESOP Loans
Debt Instrument [Line Items]
Outstanding debt							27,368,000
Debt instrument, basis spread on variable rate	2.91%
Debt instrument, periodic payment, principal	$ 620,000	$ 569,000
Non U.S. Lines of Credit
Debt Instrument [Line Items]
Long-term debt, gross							3,012,000		0
Capitalized fees & expenses							17,000		30,000
Line of credit facility, remaining borrowing capacity							11,798,000				$ 15,000
Outstanding debt							2,995,000		$ (30,000)
Proceeds from long-term lines of credit						$ 15,000	$ 11,798,000
Non U.S. Lines of Credit | LIBOR Rate
Debt Instrument [Line Items]
Line of credit facility, interest rate at period end							1.38%				1.38%	1.38%	1.38%
Non U.S. Lines of Credit | Bankers Acceptance Rate
Debt Instrument [Line Items]
Line of credit facility, interest rate at period end							1.51%				1.51%	1.51%	1.51%
Mortgages | Ames UK
Debt Instrument [Line Items]
Debt instrument, face amount | £				£ 4,000,000
Debt instrument, periodic payment, principal | £				105,000
Debt instrument, balloon payment | £				£ 2,349,000
London Interbank Offered Rate (LIBOR) | Mortgages | Ames UK
Debt Instrument [Line Items]
Debt instrument, basis spread on variable rate				1.80%
London Interbank Offered Rate (LIBOR) | ESOP Loans
Debt Instrument [Line Items]
Debt instrument, basis spread on variable rate		3.00%
London Interbank Offered Rate (LIBOR) | Mortgages | Ames UK
Debt Instrument [Line Items]
Debt instrument, basis spread on variable rate							1.85%	1.85%
Bank Bill Swap Bid Rate | Term Loan | Northcote Holdings Pty. Ltd
Debt Instrument [Line Items]
Debt instrument, basis spread on variable rate			1.95%
Bank Bill Swap Bid Rate | Revolving Credit Facility | Northcote Holdings Pty. Ltd
Debt Instrument [Line Items]
Debt instrument, basis spread on variable rate					1.90%
Troy, Ohio | Finance Lease - Real Estate
Debt Instrument [Line Items]
Long-term debt, percentage bearing fixed interest, percentage rate							5.00%				5.00%	5.00%	5.00%
Finance lease, buyout amount							$ 1
Ocala, Florida
Debt Instrument [Line Items]
Finance lease, buyout amount							$ 1
Ocala, Florida | Finance Lease - Real Estate
Debt Instrument [Line Items]
Long-term debt, percentage bearing fixed interest, percentage rate							5.60%				5.60%	5.60%	5.60%
Number of option to extend | option							2	2
Finance lease, renewal term							5 years				5 years	5 years	5 years