STOCK BASED PLANS (Details) (USD $)	1 Months Ended	12 Months Ended
	May 31, 2013	Dec. 31, 2013	Dec. 31, 2012	Nov. 09, 2010
Stock-based plans
Shares of common stock reserved for issuance				3,698,050
Expiration period		10 years
Vesting period of restricted stock and stock options granted	4 years
Shares that vest on a graduated scale based on total shareholder return in 2017 (as a percent)	50.00%
Recognized compensation expense		$ 5,700,000	$ 4,300,000
Maximum number of shares available for future grant		2,577,795
Minimum
Stock-based plans
Exercisable period		5 years
Stock Options
Stock Options
Stock Options Outstanding at the beginning of the period (in shares)		861,940	712,640
Granted (in shares)		132,100	200,000
Forfeited (in shares)		(28,600)	(50,700)
Stock Options Outstanding at the end of the period (in shares)		965,440	861,940
Stock options exercisable at the end of the period (in shares)		400
Remaining unvested options outstanding and expected to vest (in shares)		936,680
Weighted Average Exercise Price
Stock Options Outstanding at the beginning of the period (in dollars per share)		$ 59.17	$ 57.72
Granted (in dollars per share)		$ 99.38	$ 64.19
Forfeited (in dollars per share)		$ 62.40	$ 58.62
Stock Options Outstanding at the end of the period (in dollars per share)		$ 64.57	$ 59.17
Stock options exercisable at the end of the period (in dollars per share)		$ 57.77
Stock options expected to vest at the end of the period (in dollars per share)		$ 64.48
Weighted average remaining contractual term of stock options outstanding		7 years 9 months 18 days
Weighted average remaining contractual term of stock options exercisable		3 years 6 months
Weighted average remaining contractual term of stock options expected to vest		7 years 9 months 18 days
Aggregate intrinsic value		53,607,886
Aggregate intrinsic value of stock options exercisable		24,932
Aggregate intrinsic value of stock options expected to vest		52,101,542
Exercise price range of stock options
Exercise Price (in dollars per share)		$ 64.57
Number Outstanding (in shares)		965,440
Weighted Average Remaining Contractual Term		7 years 9 months 18 days
Significant assumptions used in Black-Scholes option-pricing model
Weighted average grant date fair value (in dollars per share)		$ 28.04
Weighted-average expected life of options		7 years 4 months 2 days
Weighted-average risk-free interest rate (as a percent)		1.80%
Weighted-average expected volatility (as a percent)		22.00%
Unamortized stock option expense		12,400,000
Weighted-average period for recognition of unamortized restricted stock expense		3 years 1 month 6 days
Stock Options | Minimum
Significant assumptions used in Black-Scholes option-pricing model
Weighted average grant date fair value (in dollars per share)		$ 18.12
Weighted-average expected life of options		7 years
Weighted-average risk-free interest rate (as a percent)		1.26%
Weighted-average expected volatility (as a percent)		18.00%
Stock Options | Maximum
Significant assumptions used in Black-Scholes option-pricing model
Weighted average grant date fair value (in dollars per share)		$ 36.55
Weighted-average expected life of options		7 years 6 months
Weighted-average risk-free interest rate (as a percent)		2.30%
Weighted-average expected volatility (as a percent)		26.00%
Stock Options | General and administrative expenses
Stock-based plans
Recognized compensation expense		$ 3,500,000
Stock Options | $46.49 - 55.82
Exercise price range of stock options
Exercise Price (in dollars per share)		$ 51.19
Number Outstanding (in shares)		64,500
Weighted Average Remaining Contractual Term		7 years 9 months 18 days
Stock Options | $46.49 - 55.82 | Minimum
Exercise price range of stock options
Exercise Price (in dollars per share)		$ 46.49
Stock Options | $46.49 - 55.82 | Maximum
Exercise price range of stock options
Exercise Price (in dollars per share)		$ 55.82
Stock Options | $57.77 - 60.33
Exercise price range of stock options
Exercise Price (in dollars per share)		$ 57.98
Number Outstanding (in shares)		597,400
Weighted Average Remaining Contractual Term		7 years 3 months 18 days
Stock Options | $57.77 - 60.33 | Minimum
Exercise price range of stock options
Exercise Price (in dollars per share)		$ 57.77
Stock Options | $57.77 - 60.33 | Maximum
Exercise price range of stock options
Exercise Price (in dollars per share)		$ 60.33
Stock Options | $61.64 - 69.75
Exercise price range of stock options
Exercise Price (in dollars per share)		$ 66.26
Number Outstanding (in shares)		175,440
Weighted Average Remaining Contractual Term		8 years 2 months 12 days
Stock Options | $61.64 - 69.75 | Minimum
Exercise price range of stock options
Exercise Price (in dollars per share)		$ 61.64
Stock Options | $61.64 - 69.75 | Maximum
Exercise price range of stock options
Exercise Price (in dollars per share)		$ 69.75
Stock Options | $81.80 - 110.50
Exercise price range of stock options
Exercise Price (in dollars per share)		$ 99.77
Number Outstanding (in shares)		128,100
Weighted Average Remaining Contractual Term		9 years 6 months
Stock Options | $81.80 - 110.50 | Minimum
Exercise price range of stock options
Exercise Price (in dollars per share)		$ 81.80
Stock Options | $81.80 - 110.50 | Maximum
Exercise price range of stock options
Exercise Price (in dollars per share)		$ 110.50