ACCUMULATED OTHER COMPREHENSIVE LOSS - Reclassification out of Accumulated Comprehensive Loss (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016		Dec. 31, 2015		Dec. 31, 2014
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning balance	$ (587.5)	[1]	$ (644.1)		$ (596.5)
Ending balance	(614.8)		(587.5)	[1]	(644.1)
Deferred Gain (Loss) - Hedging [Member]
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning balance	(3.8)		(2.2)		1.5
Ending balance	(3.0)		(3.8)		(2.2)
Deferred Gain (Loss) - Hedging [Member] | Interest rate swap [Member]
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning balance	(3.8)		(2.2)
Ending balance	(3.0)		(3.8)		(2.2)
Deferred Gain (Loss) - Hedging [Member] | Interest rate swap [Member] | Reclassification out of Accumulated Other Comprehensive Income (Loss) [Member]
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Change in fair value, net of tax	(1.9)		(3.2)
Other Comprehensive Income (Loss), Tax [Abstract]
Change in fair value - tax expense (benefit)	1.1		2.0
Deferred Gain (Loss) - Hedging [Member] | Interest rate swap [Member] | Interest expense [Member] | Reclassification out of Accumulated Other Comprehensive Income (Loss) [Member]
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Reclassifications into earnings, net of tax	2.7		1.6		$ 0.0
Other Comprehensive Income (Loss), Tax [Abstract]
Reclassifications into earnings - tax expense (benefit)	$ (1.6)		$ (1.0)

[1] Adjusted as a result of the adoption of certain accounting pronouncements beginning on January 1, 2016. See Note 1, "Description of Business and Summary of Significant Accounting Policies - Recently Adopted Accounting Pronouncements," for details of these adjustments.