INCOME TAXES (Details 2) (USD $) In Millions, unless otherwise specified	12 Months Ended
Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
INCOME TAXES.
Net tax benefits from share-based transactions	$ 3.4	$ 2.2	$ 1.6
Reconciliation of the beginning and ending amount of gross unrecognized tax benefits
Balance at beginning of the period	7.2us-gaap_UnrecognizedTaxBenefits	8.3us-gaap_UnrecognizedTaxBenefits	2.6us-gaap_UnrecognizedTaxBenefits
Additions for tax positions of prior years	0.5	2.0	4.0
Additions for tax positions of current year			3.7
Reductions for tax positions of prior years			(1.0)
Reductions for lapse of statute of limitations	(1.0)	(3.1)	(1.0)
Balance at the end	6.7us-gaap_UnrecognizedTaxBenefits	7.2us-gaap_UnrecognizedTaxBenefits	8.3us-gaap_UnrecognizedTaxBenefits
Unrecognized tax benefits that, if recognized, would favorably impact the effective rate	6.7	7.2	8.3
Interest accrued related to unrecognized tax benefits	$ 0.2	$ 0.3	$ 0.4

The total recognized tax benefit related to compensation cost for equity-based payment arrangements recognized in income during the period.

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Amount of unrecognized tax benefits pertaining to uncertain tax positions taken in tax returns.

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