SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Recently Adopted Accounting Pronouncements (Details) - USD ($) $ in Millions	Apr. 03, 2020	Jan. 04, 2020	Sep. 28, 2019	Sep. 27, 2019
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Operating lease assets	$ 29.0			$ 0.0
Finance lease, right-of-use asset	0.6
Operating lease liability	28.9
Present value of lease liabilities	0.6
Decrease to retained earnings upon adoption of new accounting guidance	$ (70.9)			$ (74.4)
Accounting Standards Update 2016-02
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Operating lease assets			$ 26.8
Finance lease, right-of-use asset			0.6
Operating lease liability			27.5
Present value of lease liabilities			0.6
Decrease to retained earnings upon adoption of new accounting guidance		$ (0.3)	$ 0.3