STOCK AWARD PLANS (Details) (USD $)	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
STOCK AWARD PLANS [Abstract]
Compensation cost	$ 2,927,000	$ 2,583,000	$ 5,061,000	$ 4,489,000
Income tax benefit	1,106,000	987,000	1,913,000	1,715,000
Share based Compensation Plans Combined Disclosure [Abstract]
Intrinsic value of stock options exercised	3,342,000	1,612,000
Tax benefit from stock options exercised	1,263,000	616,000
Intrinsic value of restricted stock vestings	9,230,000	11,004,000
Tax benefit from restricted stock vesting	3,489,000	4,204,000
Unrecognized compensation cost related to unvested awards	4,720,000		4,720,000
Fair value of options vested	1,717,000	1,326,000
Fair value of restricted stock vested	9,230,000	11,004,000
Fair value of stock options granted (in dollars per share)	$ 25.07	$ 22.15
Fair value of stock options granted	4,125,000	3,461,000
Fair Value Assumptions [Abstract]
Dividend yield (in hundredths)		0.00%	0.00%
Average risk-free interest rate (in hundredths)		1.10%	1.10%
Stock price volatility (in hundredths)		33.00%	34.00%
Minimum [Member]
Fair Value Assumptions [Abstract]
Estimated option term			6 years	6 years
Maximum [Member]
Fair Value Assumptions [Abstract]
Estimated option term			7 years	7 years
Sixth Price Range [Member]
Outstanding and Exercisable Stock options [Abstract]
Range of Exercise Prices, lower limit (in dollars per share)			$ 75.17
Employee Stock Award Plan [Member]
Stock Award Plan Information [Abstract]
Shares available for future grants (in shares)	2,678,355		2,678,355
Elected director first grant vesting period	The options granted to a director when first elected vest immediately
Outstanding Non-Qualified or Nonincentive Stock Awards [Roll Forward]
Outstanding at Period Start, Outstanding Non-Qualified or Nonincentive Stock Awards (in shares)			351,173
Granted, Outstanding Non-Qualified or Nonincentive Stock Awards (in shares)			109,560
Exercised, Outstanding Non-Qualified or Nonincentive Stock Awards (in shares)			(43,449)
Outstanding at Period End, Outstanding Non-Qualified or Nonincentive Stock Awards (in shares)	417,284		417,284
Weighted Average Exercise Price [Abstract]
Outstanding at Period Start, Weighted Average Exercise Price (in dollars per share)			$ 46
Granted, Weighted Average Exercise Price (in dollars per share)			$ 71
Exercised, Weighted Average Exercise Price (in dollars per share)			$ 29
Outstanding at Period End, Weighted Average Exercise Price (in dollars per share)	$ 54		$ 54
Unvested Restricted Stock Award Shares [Roll Forward]
Nonvested balance beginning of period, Unvested Restricted Stock Award Shares (in shares)			418,128
Granted, Unvested Restricted Stock Award Shares (in shares)			128,125
Vested, Unvested Restricted Stock Award Shares (in shares)			(138,794)
Forfeited, Unvested Restricted Stock Award Shares (in shares)			(6,582)
Nonvested balance end of period, Unvested Restricted Stock Award Shares (in shares)	400,877		400,877
Weighted Average Grant Date Fair Value Per Share [Abstract]
Nonvested balance beginning of period, Weighted Average Grant Date Fair Value Per Share (in dollars per share)			$ 45.39
Granted, Weighted Average Grant Date Fair Value Per Share (in dollars per share)			$ 68.28
Vested, Weighted Average Grant Date Fair Value Per Share (in dollars per share)			$ 40.69
Forfeited, Weighted Average Grant Date Fair Value Per Share (in dollars per share)			$ 63.91
Nonvested balance end of period, Weighted Average Grant Date Fair Value Per Share (in dollars per share)	$ 54.03		$ 54.03
Employee Stock Award Plan [Member] | First Price Range [Member]
Outstanding and Exercisable Stock options [Abstract]
Range of Exercise Prices, upper limit (in dollars per share)			$ 32.56
Range of Exercise Prices, lower limit (in dollars per share)			$ 23.98
Options Outstanding [Abstract]
Number Outstanding (in shares)	93,249		93,249
Weighted Average Remaining Contractual Life (in years)			3 years 4 months 24 days
Weighted Average Exercise Price, Options Outstanding (in dollars per share)	$ 31.96		$ 31.96
Options Exercisable [Abstract]
Number Exercisable (in shares)	93,249		93,249
Weighted Average Exercise Price, Options Exercisable (in dollars per share)	$ 31.96		$ 31.96
Employee Stock Award Plan [Member] | Second Price Range [Member]
Outstanding and Exercisable Stock options [Abstract]
Range of Exercise Prices, upper limit (in dollars per share)			$ 36.35
Range of Exercise Prices, lower limit (in dollars per share)			$ 34.40
Options Outstanding [Abstract]
Number Outstanding (in shares)	14,000		14,000
Weighted Average Remaining Contractual Life (in years)			1 year 3 months 18 days
Weighted Average Exercise Price, Options Outstanding (in dollars per share)	$ 34.96		$ 34.96
Options Exercisable [Abstract]
Number Exercisable (in shares)	14,000		14,000
Weighted Average Exercise Price, Options Exercisable (in dollars per share)	$ 34.96		$ 34.96
Employee Stock Award Plan [Member] | Third Price Range [Member]
Outstanding and Exercisable Stock options [Abstract]
Range of Exercise Prices, upper limit (in dollars per share)			$ 46.74
Options Outstanding [Abstract]
Number Outstanding (in shares)	100,569		100,569
Weighted Average Remaining Contractual Life (in years)			4 years 7 months 6 days
Weighted Average Exercise Price, Options Outstanding (in dollars per share)	$ 46.74		$ 46.74
Options Exercisable [Abstract]
Number Exercisable (in shares)	67,039		67,039
Weighted Average Exercise Price, Options Exercisable (in dollars per share)	$ 46.74		$ 46.74
Employee Stock Award Plan [Member] | Fourth Price Range [Member]
Outstanding and Exercisable Stock options [Abstract]
Range of Exercise Prices, upper limit (in dollars per share)			$ 70.65
Range of Exercise Prices, lower limit (in dollars per share)			$ 65.28
Options Outstanding [Abstract]
Number Outstanding (in shares)	209,466		209,466
Weighted Average Remaining Contractual Life (in years)			6 years 1 month 6 days
Weighted Average Exercise Price, Options Outstanding (in dollars per share)	$ 68.34		$ 68.34
Options Exercisable [Abstract]
Number Exercisable (in shares)	33,299		33,299
Weighted Average Exercise Price, Options Exercisable (in dollars per share)	$ 65.8		$ 65.8
Employee Stock Award Plan [Member] | Full Exercise Price Range [Member]
Outstanding and Exercisable Stock options [Abstract]
Range of Exercise Prices, upper limit (in dollars per share)			$ 70.65
Range of Exercise Prices, lower limit (in dollars per share)			$ 23.98
Options Outstanding [Abstract]
Number Outstanding (in shares)	417,284		417,284
Weighted Average Remaining Contractual Life (in years)			5 years
Weighted Average Exercise Price, Options Outstanding (in dollars per share)	$ 53.88		$ 53.88
Aggregate Intrinsic Value, Options Outstanding	10,706,000		10,706,000
Options Exercisable [Abstract]
Number Exercisable (in shares)	207,587		207,587
Weighted Average Exercise Price, Options Exercisable (in dollars per share)	$ 42.36		$ 42.36
Aggregate Intrinsic Value, Options Exercisable	7,717,000		7,717,000
2000 Director Plan [Member]
Stock Award Plan Information [Abstract]
Term of grant	10 years
Shares available for future grants (in shares)	610,041		610,041
Outstanding Non-Qualified or Nonincentive Stock Awards [Roll Forward]
Outstanding at Period Start, Outstanding Non-Qualified or Nonincentive Stock Awards (in shares)			345,938
Granted, Outstanding Non-Qualified or Nonincentive Stock Awards (in shares)			54,958
Exercised, Outstanding Non-Qualified or Nonincentive Stock Awards (in shares)			(36,000)
Outstanding at Period End, Outstanding Non-Qualified or Nonincentive Stock Awards (in shares)	364,896		364,896
Weighted Average Exercise Price [Abstract]
Outstanding at Period Start, Weighted Average Exercise Price (in dollars per share)			$ 45.84
Granted, Weighted Average Exercise Price (in dollars per share)			$ 75.17
Exercised, Weighted Average Exercise Price (in dollars per share)			$ 36.79
Outstanding at Period End, Weighted Average Exercise Price (in dollars per share)	$ 51.15		$ 51.15
Unvested Restricted Stock Award Shares [Roll Forward]
Nonvested balance beginning of period, Unvested Restricted Stock Award Shares (in shares)			348
Granted, Unvested Restricted Stock Award Shares (in shares)			10,536
Vested, Unvested Restricted Stock Award Shares (in shares)			(732)
Nonvested balance end of period, Unvested Restricted Stock Award Shares (in shares)	10,152		10,152
Weighted Average Grant Date Fair Value Per Share [Abstract]
Nonvested balance beginning of period, Weighted Average Grant Date Fair Value Per Share (in dollars per share)			$ 62.99
Granted, Weighted Average Grant Date Fair Value Per Share (in dollars per share)			$ 75.65
Vested, Weighted Average Grant Date Fair Value Per Share (in dollars per share)			$ 69.63
Nonvested balance end of period, Weighted Average Grant Date Fair Value Per Share (in dollars per share)	$ 75.65		$ 75.65
2000 Director Plan [Member] | First Price Range [Member]
Outstanding and Exercisable Stock options [Abstract]
Range of Exercise Prices, lower limit (in dollars per share)			$ 17.88
Options Outstanding [Abstract]
Number Outstanding (in shares)	12,000		12,000
Weighted Average Remaining Contractual Life (in years)			9 months 18 days
Weighted Average Exercise Price, Options Outstanding (in dollars per share)	$ 17.88		$ 17.88
Options Exercisable [Abstract]
Number Exercisable (in shares)	12,000		12,000
Weighted Average Exercise Price, Options Exercisable (in dollars per share)	$ 17.88		$ 17.88
2000 Director Plan [Member] | Second Price Range [Member]
Outstanding and Exercisable Stock options [Abstract]
Range of Exercise Prices, upper limit (in dollars per share)			$ 29.60
Range of Exercise Prices, lower limit (in dollars per share)			$ 20.28
Options Outstanding [Abstract]
Number Outstanding (in shares)	36,000		36,000
Weighted Average Remaining Contractual Life (in years)			4 years 6 months
Weighted Average Exercise Price, Options Outstanding (in dollars per share)	$ 26.49		$ 26.49
Options Exercisable [Abstract]
Number Exercisable (in shares)	36,000		36,000
Weighted Average Exercise Price, Options Exercisable (in dollars per share)	$ 26.49		$ 26.49
2000 Director Plan [Member] | Third Price Range [Member]
Outstanding and Exercisable Stock options [Abstract]
Range of Exercise Prices, upper limit (in dollars per share)			$ 36.82
Range of Exercise Prices, lower limit (in dollars per share)			$ 35.17
Options Outstanding [Abstract]
Number Outstanding (in shares)	56,036		56,036
Weighted Average Remaining Contractual Life (in years)			3 years 3 months 18 days
Weighted Average Exercise Price, Options Outstanding (in dollars per share)	$ 35.91		$ 35.91
Options Exercisable [Abstract]
Number Exercisable (in shares)	56,036		56,036
Weighted Average Exercise Price, Options Exercisable (in dollars per share)	$ 35.91		$ 35.91
2000 Director Plan [Member] | Fourth Price Range [Member]
Outstanding and Exercisable Stock options [Abstract]
Range of Exercise Prices, upper limit (in dollars per share)			$ 56.45
Range of Exercise Prices, lower limit (in dollars per share)			$ 41.24
Options Outstanding [Abstract]
Number Outstanding (in shares)	145,596		145,596
Weighted Average Remaining Contractual Life (in years)			6 years 6 months
Weighted Average Exercise Price, Options Outstanding (in dollars per share)	$ 52.14		$ 52.14
Options Exercisable [Abstract]
Number Exercisable (in shares)	145,596		145,596
Weighted Average Exercise Price, Options Exercisable (in dollars per share)	$ 52.14		$ 52.14
2000 Director Plan [Member] | Fifth Price Range [Member]
Outstanding and Exercisable Stock options [Abstract]
Range of Exercise Prices, upper limit (in dollars per share)			$ 62.48
Range of Exercise Prices, lower limit (in dollars per share)			$ 61.89
Options Outstanding [Abstract]
Number Outstanding (in shares)	60,306		60,306
Weighted Average Remaining Contractual Life (in years)			8 years 10 months 24 days
Weighted Average Exercise Price, Options Outstanding (in dollars per share)	$ 62.38		$ 62.38
Options Exercisable [Abstract]
Number Exercisable (in shares)	60,306		60,306
Weighted Average Exercise Price, Options Exercisable (in dollars per share)	$ 62.38		$ 62.38
2000 Director Plan [Member] | Sixth Price Range [Member]
Options Outstanding [Abstract]
Number Outstanding (in shares)	54,958		54,958
Weighted Average Remaining Contractual Life (in years)			9 years 9 months 18 days
Weighted Average Exercise Price, Options Outstanding (in dollars per share)	$ 75.17		$ 75.17
Options Exercisable [Abstract]
Number Exercisable (in shares)	239		239
Weighted Average Exercise Price, Options Exercisable (in dollars per share)	$ 75.17		$ 75.17
2000 Director Plan [Member] | Full Exercise Price Range [Member]
Outstanding and Exercisable Stock options [Abstract]
Range of Exercise Prices, upper limit (in dollars per share)			$ 75.17
Range of Exercise Prices, lower limit (in dollars per share)			$ 17.88
Options Outstanding [Abstract]
Number Outstanding (in shares)	364,896		364,896
Weighted Average Remaining Contractual Life (in years)			6 years 6 months
Weighted Average Exercise Price, Options Outstanding (in dollars per share)	$ 51.15		$ 51.15
Aggregate Intrinsic Value, Options Outstanding	10,358,000		10,358,000
Options Exercisable [Abstract]
Number Exercisable (in shares)	310,177		310,177
Weighted Average Exercise Price, Options Exercisable (in dollars per share)	$ 46.92		$ 46.92
Aggregate Intrinsic Value, Options Exercisable	10,119,000		10,119,000
Employee Stock Award Plan - Options Granted After to January 25, 2010 [Member]
Stock Award Plan Information [Abstract]
Term of grant	7 years
Vesting period	3 years
Employee Stock Award Plan - Options Granted Prior to January 25, 2010 [Member]
Stock Award Plan Information [Abstract]
Term of grant	5 years
Vesting period	3 years
Stock Options [Member]
Share based Compensation Plans Combined Disclosure [Abstract]
Weighted average period of recognition in years			1 year 6 months
Restricted Stock [Member]
Share based Compensation Plans Combined Disclosure [Abstract]
Unrecognized compensation cost related to unvested awards		$ 19,325,000		$ 19,325,000
Weighted average period of recognition in years			3 years 1 month 6 days