BORROWINGS - Schedule of Short-Term and Long-Term Debt (Details) - USD ($) $ in Millions	12 Months Ended
	Oct. 01, 2021	Oct. 02, 2020	Sep. 27, 2019
Current maturities of long-term debt
Current maturities of long-term debt	$ 2.8	$ 2.5
Net repayments of long term debt current maturities	0.3
Non-current maturities of long-term debt:
Long-term debt excluding current maturities, gross	477.8	508.8
Net proceeds from long-term debt, excluding current maturities	(31.0)
Unamortized Issuance Costs and Debt Discounts [Abstract]
Total	(46.1)	(56.0)
Amortization of deferred loan costs	3.5	7.0	$ 3.2
Total	9.9
Total debt outstanding, net	434.5	455.3
Net proceeds from debt, net of issuance costs	(20.8)
Convertible Debt
Non-current maturities of long-term debt:
Long-term debt excluding current maturities, gross	$ 200.0	$ 200.0
Weighted-average interest rate, long-term debt	10.90%	10.90%
Proceeds from convertible debt	$ 0.0
Unamortized Issuance Costs and Debt Discounts [Abstract]
Debt issuance costs	(37.6)	$ (45.4)
Unamortized issuance costs - Convertible Notes	(4.1)	(5.0)
Amortization of deferred loan costs	7.8
Decrease in unamortized discount	0.9
Other Debt
Current maturities of long-term debt
Current maturities of long-term debt	2.8	2.5
Proceeds from repayment of other debt	0.3
Non-current maturities of long-term debt:
Long-term debt excluding current maturities, gross	7.8	8.8
Proceeds from repayment of other long-term debt	(1.0)
Senior Secured Notes | Secured Debt
Non-current maturities of long-term debt:
Long-term debt excluding current maturities, gross	$ 270.0	$ 300.0
Weighted-average interest rate, long-term debt	8.20%	8.20%
Proceeds from issuance of senior secured notes	$ (30.0)
Revolving Credit Facility | Asset-Based Loan Revolving Credit Facility
Non-current maturities of long-term debt:
Long-term debt excluding current maturities, gross	0.0	$ 0.0
Repayments of long term lines of credit	0.0
Secured Debt
Unamortized Issuance Costs and Debt Discounts [Abstract]
Debt issuance costs	(4.4)	$ (5.6)
Amortization of deferred loan costs	$ 1.2