GOODWILL AND OTHER INTANGIBLE ASSETS (Details) - USD ($) $ in Millions		12 Months Ended
	Jul. 01, 2019	Dec. 31, 2019	Dec. 31, 2018
Goodwill and other intangible assets
Changes to the carrying amount of goodwill		$ 0.0	$ 0.0
Goodwill impairment loss	$ 0.0
Intangible assets other than goodwill
Amortized intangible assets, accumulated amortization		(8.0)	(6.8)
Unamortized intangible assets, carrying amount		0.4	0.4
Total intangible assets, gross carrying amount		8.7	8.7
Total intangible assets, net carrying amount		0.7	1.9
Contractual service agreements
Intangible assets other than goodwill
Amortized intangible assets, gross carrying amount		8.3	8.3
Amortized intangible assets, accumulated amortization		(8.0)	(6.8)
Amortized intangible assets, net carrying amount		$ 0.3	$ 1.5
Remaining amortization period		1 year