DISCONTINUED OPERATIONS - Other (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Discontinued operations in the Consolidated Statement of Comprehensive Income
Gain (loss) on disposition of discontinued operations – net of tax	$ 2.6	$ 0.0	$ 63.7	$ 3.5
Discontinued Operations, Disposed of by Sale
Discontinued operations in the Consolidated Statement of Comprehensive Income
Gain (loss) on disposition of discontinued operations	2.8	0.0	85.8	4.6
(Provision for) benefit from income taxes	(0.2)	0.0	(22.1)	(1.1)
Gain (loss) on disposition of discontinued operations – net of tax	2.6	$ 0.0	63.7	3.5
Discontinued Operations, Disposed of by Sale | MHPS
Discontinued operations in the Consolidated Statement of Comprehensive Income
Gain (loss) on disposition of discontinued operations	2.8		82.3
(Provision for) benefit from income taxes	(0.2)		(21.6)
Gain (loss) on disposition of discontinued operations – net of tax	2.6		60.7
Discontinued Operations, Disposed of by Sale | Atlas
Discontinued operations in the Consolidated Statement of Comprehensive Income
Gain (loss) on disposition of discontinued operations	0.0		3.5
(Provision for) benefit from income taxes	0.0		(0.5)
Gain (loss) on disposition of discontinued operations – net of tax	$ 0.0		$ 3.0	3.0
Discontinued Operations, Disposed of by Sale | Truck Business
Discontinued operations in the Consolidated Statement of Comprehensive Income
Gain (loss) on disposition of discontinued operations – net of tax				$ 0.5