ACCUMULATED OTHER COMPREHENSIVE LOSS - Components of Accumulated Other 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)
Other comprehensive income	[2]	(6.4)		(2.1)		(93.4)
Ending balance		(614.8)		(587.5)	[1]	(644.1)
Accumulated Other Comprehensive Loss [Member]
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning balance		(245.3)		(243.2)		(149.8)
Other comprehensive income	[2]	(6.4)		(2.1)		(93.4)
Ending balance		(251.7)		(245.3)		(243.2)
Foreign Currency Translation [Member]
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning balance		(23.5)		(5.4)		19.2
Other comprehensive income		(0.5)		(18.1)		(24.6)
Ending balance		(24.0)		(23.5)		(5.4)
Other Comprehensive Income (Loss), Tax, Portion Attributable to Parent, Parenthetical Disclosures [Abstract]
Other comprehensive income (loss), tax expense (benefit)		(1.1)		5.1		2.1
Actuarial (Loss) Gain on Post-retirement Benefits [Member]
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning balance		(217.7)		(235.6)		(170.5)
Other comprehensive income		(6.7)
Ending balance		(224.4)		(217.7)		(235.6)
Actuarial (Loss) Gain on Post-retirement Benefits - Amortization of pension related costs [Member]
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Other comprehensive income		7.6		7.2		4.5
Other Comprehensive Income (Loss), Tax, Portion Attributable to Parent, Parenthetical Disclosures [Abstract]
Other comprehensive income (loss), tax expense (benefit)		(1.3)		(1.3)		(0.1)
Actuarial (Loss) Gain on Post-retirement Benefits - Pension re-measurement [Member]
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Other comprehensive income		(14.3)		(6.9)		(69.6)
Other Comprehensive Income (Loss), Tax, Portion Attributable to Parent, Parenthetical Disclosures [Abstract]
Other comprehensive income (loss), tax expense (benefit)		4.1		3.3		42.0
Actuarial (Loss) Gain on Post-retirement Benefits - Settlement of certain pension liabilities [Member]
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Other comprehensive income				17.3
Other Comprehensive Income (Loss), Tax, Portion Attributable to Parent, Parenthetical Disclosures [Abstract]
Other comprehensive income (loss), tax expense (benefit)				(3.7)
Actuarial (Loss) Gain on Post-retirement Benefits - Other [Member]
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Other comprehensive income						0.3
Deferred Gain (Loss) - Hedging [Member]
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning balance		(3.8)		(2.2)		1.5
Other comprehensive income		0.8		(1.6)		(3.7)
Ending balance		(3.0)		(3.8)		(2.2)
Other Comprehensive Income (Loss), Tax, Portion Attributable to Parent, Parenthetical Disclosures [Abstract]
Other comprehensive income (loss), tax expense (benefit)		(0.5)		1.0		2.3
Other [Member]
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning balance		(0.3)		(0.3)		0.0
Other comprehensive income		0.0				(0.3)
Ending balance		$ (0.3)		$ (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 17, “Accumulated Other Comprehensive Loss,” regarding the changes in the accumulated balances for each component of other comprehensive loss during 2016, 2015 and 2014.