STOCK-BASED COMPENSATION (Details 3) (USD $) In Millions, except Share data, unless otherwise specified	3 Months Ended
Mar. 31, 2015	Mar. 31, 2014
Restricted Stock Awards \| Outside Director
Shares
Granted (in shares)	0	0
Restricted Stock Awards \| Minimum
Summary of Stock-Based Compensation Plans
Vesting period	3 years
Restricted Stock Awards \| Maximum
Summary of Stock-Based Compensation Plans
Vesting period	5 years
Time-based restricted stock awards
Shares
Outstanding at beginning of period (in shares)	751,020
Granted (in shares)	411,802
Vested (in shares)	(207,495)
Forfeited (in shares)	(13,119)
Outstanding at end of period (in shares)	942,208
Weighted Average Price
Outstanding at beginning of period (in dollars per share)	30.61
Granted (in dollars per share)	38.85	36.83
Vested (in dollars per share)	23.27
Forfeited (in dollars per share)	34.05
Outstanding at end of period (in dollars per share)	35.78
Additional disclosures
Total fair value of restricted stock awards vested	8.4	14.6
Total unrecognized stock compensation expense	29.3
Weighted average period to recognize unrecognized compensation cost	2 years 4 months 28 days
Performance-based restricted stock awards
Shares
Outstanding at beginning of period (in shares)	518,553
Granted (in shares)	149,284
Vested (in shares)	(144,445)
Outstanding at end of period (in shares)	523,392
Weighted Average Price
Outstanding at beginning of period (in dollars per share)	29.64
Granted (in dollars per share)	39.95	36.85
Vested (in dollars per share)	22.05
Outstanding at end of period (in dollars per share)	35.64
Additional disclosures
Total fair value of restricted stock awards vested	5.8	2.7
Total unrecognized stock compensation expense	12.3
Weighted average period to recognize unrecognized compensation cost	2 years 3 months 15 days

Unrecognized cost of unvested share-based compensation awards.

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-Publisher FASB

-Name Accounting Standards Codification

-Topic 718

-SubTopic 10

-Section 50

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Weighted average period over which unrecognized compensation is expected to be recognized for equity-based compensation plans, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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The number of equity-based payment instruments, excluding stock (or unit) options, that were forfeited during the reporting period.

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Weighted average fair value as of the grant date of equity-based award plans other than stock (unit) option plans that were not exercised or put into effect as a result of the occurrence of a terminating event.

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The number of grants made during the period on other than stock (or unit) option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, performance target plan).

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The weighted average fair value at grant date for nonvested equity-based awards issued during the period on other than stock (or unit) option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, performance target plan).

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The number of non-vested equity-based payment instruments, excluding stock (or unit) options, that validly exist and are outstanding as of the balance sheet date.

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The weighted average fair value of nonvested awards on equity-based plans excluding option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, revenue or profit achievement stock award plan) for which the employer is contingently obligated to issue equity instruments or transfer assets to an employee who has not yet satisfied service or performance criteria necessary to gain title to proceeds from the sale of the award or underlying shares or units.

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The number of equity-based payment instruments, excluding stock (or unit) options, that vested during the reporting period.

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Fair value of share-based awards for which the grantee gained the right by satisfying service and performance requirements, to receive or retain shares or units, other instruments, or cash.

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