ACCUMULATED OTHER COMPREHENSIVE LOSS - Components of Accumulated Other Comprehensive Loss (Details) - USD ($) $ in Millions		3 Months Ended		6 Months Ended
		Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016		Jun. 30, 2015
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning balance	[1]			$ (587.5)
Other comprehensive income (loss)		$ 4.8	$ 2.5	8.4	[2]	$ (11.1)
Ending balance		(561.7)		(561.7)
Accumulated Other Comprehensive Loss [Member]
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning balance				(245.3)
Other comprehensive income (loss)	[2]			8.4
Ending balance		(236.9)		(236.9)
Foreign Currency Translation [Member]
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning balance				(23.5)
Other comprehensive income (loss)				5.3
Ending balance		(18.2)		(18.2)
Other Comprehensive Income (Loss), Tax, Portion Attributable to Parent, Parenthetical Disclosures [Abstract]
Other comprehensive income (loss), tax expense (benefit)				0.6
Actuarial (Loss) Gain on Post-retirement Benefits [Member]
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning balance				(217.7)
Other comprehensive income (loss)				3.8
Ending balance		(213.9)		(213.9)
Other Comprehensive Income (Loss), Tax, Portion Attributable to Parent, Parenthetical Disclosures [Abstract]
Other comprehensive income (loss), tax expense (benefit)				0.7
Deferred Gain (Loss) - Hedging [Member]
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning balance				(3.8)
Other comprehensive income (loss)				(0.7)
Ending balance		(4.5)		(4.5)
Other Comprehensive Income (Loss), Tax, Portion Attributable to Parent, Parenthetical Disclosures [Abstract]
Other comprehensive income (loss), tax expense (benefit)				(0.4)
Other [Member]
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning balance				(0.3)
Other comprehensive income (loss)				0.0
Ending balance		$ (0.3)		$ (0.3)

[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.

[2] See Note 13, “Accumulated Other Comprehensive Loss,” regarding the changes in the accumulated balances for each component of other comprehensive income during the six months ended June 30, 2016.