NON-OPERATING INCOME (EXPENSE) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Nonoperating Income (Expense) [Abstract]
Interest income	$ 2.0	$ 5.0	$ 6.0	$ 8.0
SERP market adjustments	0.0	0.0	1.0	(0.0)
Interest expense	(5.0)	(5.0)	(9.0)	(10.0)
Amortization of debt charges	(1.0)	(0.0)	(1.0)	(0.0)
Capitalized interest	1.0	1.0	2.0	2.0
Interest expense, net	(2.0)	0.0	(1.0)	(1.0)
Net periodic pension cost, excluding service cost	(1.0)	(1.0)	(1.0)	(2.0)
Gain on acquisition of controlling interest	0.0	0.0	14.0	0.0
Foreign currency gain (loss)	(1.0)	1.0	(4.0)	0.0
Other non-operating items	(2.0)	(1.0)	9.0	(2.0)
Total non-operating expense	$ (4.0)	$ (0.0)	$ 8.0	$ (3.0)