STOCK-BASED COMPENSATION PLANS (Details) (USD $) In Millions, except Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	May 14, 2014	May 25, 2011
STOCK-BASED COMPENSATION PLANS [Abstract]
Shares of common stock authorized for stock-based compensation plan (in shares)	4,000,000
Additional shares of common stock authorized for stock-based compensation plan ( in shares)				1,000,000	900,000
Number of shares available for grant (in shares)	1,723,456
Term of options	10 years
Options vesting period	5 years
Options [Abstract]
Options outstanding, shares (in shares)	2,151,776
Options outstanding, weighted-average exercise price (in dollars per share)	$ 25.92
Options outstanding, weighted-average remaining life (years)	5 years 9 months 25 days
Options exercisable, shares (in shares)	1,396,303
Options exercisable, weighted-average exercise price (in dollars per share)	$ 23.12
Weighted-average remaining contractual term of outstanding stock options	5 years 9 months 18 days
Weighted-average remaining contractual term of outstanding and exercisable stock options	4 years 8 months 12 days
Aggregate intrinsic value of outstanding stock options	$ 26.3
Aggregate intrinsic value of exercisable stock options	21.0
Fair value assumptions and methodology [Abstract]
Fair value assumptions, method used	Black-Scholes model	Black-Scholes model	Black-Scholes model
Weighted-average fair value of options granted (in dollars per share)	$ 8.38	$ 6.24	$ 6.40
Assumptions [Abstract]
Weighted-average expected life	6 years 6 months	7 years 2 months 23 days	7 years 4 months 24 days
Future dividend yield (in hundredths)	3.70%	3.90%	3.90%
Share price volatility (in hundredths)	30.71%	31.21%	31.79%
Weighted-average risk-free interest rate (in hundredths)	2.69%	1.91%	2.34%
Unrecognized stock-based compensation expense related to non-vested stock options	3.8
Weighted average period for recognition of unrecognized compensation cost	2 years 9 months 18 days
Total fair value of stock options vested	1.9	2.0	1.7
Proceeds from stock option exercises	9.4	16.0
Related tax benefits from stock option exercises	1.6	1.6
Shares issued in connection with stock option exercise (in shares)	359,679	680,705
Total intrinsic value of options exercised	5.7	7.9	4.9
$0.00 - $18.00 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Exercise price range, lower range limit (in dollars per share)	$ 0
Exercise price range, upper range limit (in dollars per share)	$ 18.00
Options [Abstract]
Options outstanding, shares (in shares)	163,916
Options outstanding, weighted-average exercise price (in dollars per share)	$ 17.60
Options outstanding, weighted-average remaining life (years)	4 years 1 month 24 days
Options exercisable, shares (in shares)	163,916
Options exercisable, weighted-average exercise price (in dollars per share)	$ 17.60
$18.001 - $23.00 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Exercise price range, lower range limit (in dollars per share)	$ 18.001
Exercise price range, upper range limit (in dollars per share)	$ 23.00
Options [Abstract]
Options outstanding, shares (in shares)	629,242
Options outstanding, weighted-average exercise price (in dollars per share)	$ 19.63
Options outstanding, weighted-average remaining life (years)	3 years 8 months 19 days
Options exercisable, shares (in shares)	579,234
Options exercisable, weighted-average exercise price (in dollars per share)	$ 19.64
$23.001 - $28.00 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Exercise price range, lower range limit (in dollars per share)	$ 23.001
Exercise price range, upper range limit (in dollars per share)	$ 28.00
Options [Abstract]
Options outstanding, shares (in shares)	433,612
Options outstanding, weighted-average exercise price (in dollars per share)	$ 25.55
Options outstanding, weighted-average remaining life (years)	4 years 5 months 12 days
Options exercisable, shares (in shares)	355,440
Options exercisable, weighted-average exercise price (in dollars per share)	$ 25.16
$28.001 - $29.00 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Exercise price range, lower range limit (in dollars per share)	$ 28.001
Exercise price range, upper range limit (in dollars per share)	$ 29.00
Options [Abstract]
Options outstanding, shares (in shares)	304,939
Options outstanding, weighted-average exercise price (in dollars per share)	$ 28.78
Options outstanding, weighted-average remaining life (years)	7 years 2 months 19 days
Options exercisable, shares (in shares)	145,582
Options exercisable, weighted-average exercise price (in dollars per share)	$ 28.78
$29.001 - $30.00 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Exercise price range, lower range limit (in dollars per share)	$ 29.001
Exercise price range, upper range limit (in dollars per share)	$ 30.00
Options [Abstract]
Options outstanding, shares (in shares)	342,654
Options outstanding, weighted-average exercise price (in dollars per share)	$ 29.79
Options outstanding, weighted-average remaining life (years)	8 years 2 months 16 days
Options exercisable, shares (in shares)	108,559
Options exercisable, weighted-average exercise price (in dollars per share)	$ 29.79
$30.001 - $40.00 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Exercise price range, lower range limit (in dollars per share)	$ 30.001
Exercise price range, upper range limit (in dollars per share)	$ 40.00
Options [Abstract]
Options outstanding, shares (in shares)	277,413
Options outstanding, weighted-average exercise price (in dollars per share)	$ 37.77
Options outstanding, weighted-average remaining life (years)	9 years 2 months 19 days
Options exercisable, shares (in shares)	43,572
Options exercisable, weighted-average exercise price (in dollars per share)	$ 37.77
Stock Options [Member]
Options, Outstanding [Roll Forward]
Outstanding, beginning of period (in shares)	2,274,891	2,760,723
Granted (in shares)	281,603	369,589
Exercised (in shares)	(380,265)	(840,556)
Forfeited (in shares)	(24,453)	(14,865)
Outstanding, end of period (in shares)	2,151,776	2,274,891	2,760,723
Exercisable, end of period (in shares)	1,396,303
Weighted-average exercise price of shares [Abstract]
Outstanding, beginning of period (in dollars per share)	$ 24.03	$ 22.86
Granted (in dollars per share)	$ 37.77	$ 29.79
Exercised (in dollars per share)	$ 23.19	$ 22.70
Forfeited (in dollars per share)	$ 28.71	$ 24.45
Outstanding, end of period (in dollars per share)	$ 25.92	$ 24.03	$ 22.86
Exercisable, end of period (in dollars per share)	$ 23.12
Stock-based compensation expense related to incentive and non-qualified stock options recognized	2.0	2.0	1.8
Income tax benefit recognized	0.9	1.1	0.8
Restricted Stock [Member]
Weighted-average exercise price of shares [Abstract]
Stock-based compensation expense related to incentive and non-qualified stock options recognized	$ 2.0	$ 2.0	$ 1.8
Restricted Shares [Roll Forward]
Unvested, beginning of period (in shares)	260,965	192,083
Awards (in shares)	53,518	142,353
Forfeitures (in shares)	(4,329)	(2,896)
Vestings (in shares)	(64,433)	(70,575)
Unvested, end of period (in shares)	245,721	260,965	192,083
Weighted-average grant date fair value [Abstract]
Unvested, beginning of period (in dollars per share)	$ 23.42	$ 23.98
Awards (in dollars per share)	$ 37.77	$ 22.13
Forfeitures (in dollars per share)	$ 29.98	$ 25.34
Vestings (in dollars per share)	$ 24.55	$ 22.28
Unvested, end of period (in dollars per share)	$ 26.13	$ 23.42	$ 23.98