STOCK-BASED COMPENSATION (Details 3) (USD $)	6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012
Restricted Share Units
Performance Stock Rights and Restricted Stock Units Activity
Outstanding at the beginning of the period (in shares)	505,690
Granted (in shares)	189,594
Dividend equivalents (in shares)	11,848
Vested and released (in shares)	(204,419)
Forfeited (in shares)	(2,415)
Outstanding at the end of period (in shares)	500,298
Weighted-Average Fair Value
Outstanding at the beginning of the period (in dollars per share)	$ 48.38
Granted (in shares)	$ 56.01	$ 53.24
Dividend equivalents (in dollars per share)	$ 52.20
Vested and released (in dollars per share)	$ 46.27
Forfeited (in dollars per share)	$ 51.31
Outstanding at the end of the period (in dollars per share)	$ 52.21
Total intrinsic value
Total intrinsic value of restricted share units vested and released (in dollars)	$ 11,400,000	$ 10,400,000
Additional disclosures
Compensation cost not yet recognized	14,800,000
Weighted-average period over which compensation cost is to be recognized	2 years 5 months
Tax benefit realized from the distribution of shares	4,600,000	4,200,000
Performance Stock Rights Accounted For As Liability Awards
Performance Stock Rights and Restricted Stock Units Activity
Outstanding at the beginning of the period (in shares)	189,093
Granted (in shares)	90,496
Distributed (in shares)	(61,753)
Adjustment for final payout (in shares)	14,255
Outstanding at the end of period (in shares)	232,091
Weighted-Average Fair Value
Outstanding at the end of the period, fair value as of the reporting date (in dollars per share)	$ 46.66
Performance Stock Rights Accounted For As Equity Awards
Performance Stock Rights and Restricted Stock Units Activity
Outstanding at the beginning of the period (in shares)	108,314
Granted (in shares)	22,636
Distributed (in shares)	(94,758)
Adjustment for final payout (in shares)	21,867
Outstanding at the end of period (in shares)	58,059
Weighted-Average Fair Value
Outstanding at the beginning of the period (in dollars per share)	$ 65.38
Granted (in shares)	$ 48.50	$ 52.70
Distributed (in dollars per share)	$ 72.36
Adjustment for final payout (in dollars per shares)	$ 72.36
Outstanding at the end of the period (in dollars per share)	$ 50.04
Performance Stock Rights
Total intrinsic value
Total intrinsic value of performance stock rights distributed during the period (in dollars)	8,800,000	4,700,000.0
Additional disclosures
Compensation cost not yet recognized	4,500,000
Weighted-average period over which compensation cost is to be recognized	1 year 5 months
Tax benefit realized from the distribution of shares	$ 3,600,000	$ 1,900,000
Performance Stock Rights | Minimum
Assumptions Incorporated into Valuation Models
Period of historical volatility used to estimate expected volatility	2 years
Risk-free interest rate, minimum (as a percent)	0.26%
Expected Dividend Rate	5.18%
Expected volatility, minimum (as a percent)	19.00%
Performance Stock Rights | Maximum
Assumptions Incorporated into Valuation Models
Period of historical volatility used to estimate expected volatility	3 years
Risk-free interest rate, maximum (as a percent)	1.27%
Expected Dividend Rate	5.34%
Expected volatility rate, maximum (as a percent)	36.00%