INCOME TAXES - Summary of Deferred Tax Assets and Liabilities (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Deferred tax assets
Accounts receivable, principally due to allowance for doubtful accounts	$ 1.4	$ 0.0
Inventories	5.9	5.9
NOL carryforwards	5.0	6.9
Accrued pension	5.8	2.1
Stock-based compensation	4.8	3.7
Compensation-related accruals	1.2	0.7
Warranty	2.7	2.1
OPEB obligation	1.0	0.9
Accrued liabilities and other items	8.3	8.4
Gross deferred tax assets	36.1	30.7
Valuation allowance	(4.3)	(4.8)
Net deferred tax assets	31.8	25.9
Deferred tax liabilities:
Intangibles	(92.3)	(85.6)
Plant and equipment	(24.5)	(26.8)
Gross deferred tax liabilities	(116.8)	(112.4)
Net deferred tax liabilities	$ (85.0)	$ (86.5)