STOCK AWARD PLANS (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
STOCK AWARD PLANS [Abstract]
Compensation cost	$ 3,127,000	$ 3,551,000	$ 8,378,000	$ 8,824,000
Income tax benefit	$ 1,161,000	$ 1,329,000	3,125,000	3,327,000
Share based Compensation Plans Combined Disclosure [Abstract]
Intrinsic value of stock options exercised			2,555,000	11,624,000
Tax benefit from stock options exercised			953,000	4,382,000
Intrinsic value of restricted stock vesting			9,055,000	14,021,000
Tax benefit from restricted stock vesting			3,378,000	5,286,000
Fair value of options vested			2,194,000	2,103,000
Fair value of restricted stock vested			$ 9,055,000	$ 14,021,000
Fair value of stock options granted (in dollars per share)			$ 25.18	$ 36.05
Fair value of stock options granted			$ 2,893,000	$ 4,226,000
Fair Value Assumptions [Abstract]
Dividend yield			0.00%	0.00%
Average risk-free interest rate			1.30%	2.00%
Stock price volatility			33.00%	33.00%
Estimated option term			6 years
Minimum [Member]
Fair Value Assumptions [Abstract]
Estimated option term				6 years
Maximum [Member]
Fair Value Assumptions [Abstract]
Estimated option term				7 years
Employee Stock Award Plan [Member]
Stock Award Plan Information [Abstract]
Term of grant			7 years
Vesting period			3 years
Shares available for future grants (in shares)	2,327,771		2,327,771
Outstanding Non-Qualified or Nonincentive Stock Awards [Roll Forward]
Outstanding at Period Start, Outstanding Non-Qualified or Nonincentive Stock Awards (in shares)			322,956
Granted, Outstanding Non-Qualified or Nonincentive Stock Awards (in shares)			114,894
Exercised, Outstanding Non-Qualified or Nonincentive Stock Awards (in shares)			0
Forfeited, Outstanding Non-Qualified or Nonincentive Stock Awards (in shares)			(7,418)
Outstanding at Period End, Outstanding Non-Qualified or Nonincentive Stock Awards (in shares)	430,432		430,432
Weighted Average Exercise Price [Abstract]
Outstanding at Period Start, Weighted Average Exercise Price (in dollars per share)			$ 69.95
Granted, Weighted Average Exercise Price (in dollars per share)			74.99
Exercised, Weighted Average Exercise Price (in dollars per share)			0
Forfeited, Weighted Average Exercise Price (in dollars per share)			86.28
Outstanding at Period End, Weighted Average Exercise Price (in dollars per share)	$ 71.01		$ 71.01
Unvested Restricted Stock Award Shares [Roll Forward]
Nonvested balance beginning of period, Unvested Restricted Stock Award Shares (in shares)			321,453
Granted, Unvested Restricted Stock Award Shares (in shares)			122,740
Vested, Unvested Restricted Stock Award Shares (in shares)			(113,788)
Forfeited, Unvested Restricted Stock Award Shares (in shares)			(17,041)
Nonvested balance end of period, Unvested Restricted Stock Award Shares (in shares)	313,364		313,364
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)			$ 71.04
Granted, Weighted Average Grant Date Fair Value Per Share (in dollars per share)			75.04
Vested, Weighted Average Grant Date Fair Value Per Share (in dollars per share)			60.74
Forfeited, Weighted Average Grant Date Fair Value Per Share (in dollars per share)			81.98
Nonvested balance end of period, Weighted Average Grant Date Fair Value Per Share (in dollars per share)	$ 75.75		75.75
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)			36.35
Range of Exercise Prices, lower limit (in dollars per share)			$ 31.35
Options Outstanding [Abstract]
Number Outstanding (in shares)	16,910		16,910
Weighted Average Remaining Contractual Life			1 year 4 months 24 days
Weighted Average Exercise Price, Options Outstanding (in dollars per share)	$ 32.82		$ 32.82
Options Exercisable [Abstract]
Number Exercisable (in shares)	16,910		16,910
Weighted Average Exercise Price, Options Exercisable (in dollars per share)	$ 32.82		$ 32.82
Employee Stock Award Plan [Member] | Second Price Range [Member]
Outstanding and Exercisable Stock options [Abstract]
Range of Exercise Prices, lower limit (in dollars per share)			$ 46.74
Options Outstanding [Abstract]
Number Outstanding (in shares)	56,629		56,629
Weighted Average Remaining Contractual Life			2 years 3 months 18 days
Weighted Average Exercise Price, Options Outstanding (in dollars per share)	$ 46.74		$ 46.74
Options Exercisable [Abstract]
Number Exercisable (in shares)	56,629		56,629
Weighted Average Exercise Price, Options Exercisable (in dollars per share)	$ 46.74		$ 46.74
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)			74.99
Range of Exercise Prices, lower limit (in dollars per share)			$ 65.28
Options Outstanding [Abstract]
Number Outstanding (in shares)	283,963		283,963
Weighted Average Remaining Contractual Life			4 years 10 months 24 days
Weighted Average Exercise Price, Options Outstanding (in dollars per share)	$ 70.98		$ 70.98
Options Exercisable [Abstract]
Number Exercisable (in shares)	141,669		141,669
Weighted Average Exercise Price, Options Exercisable (in dollars per share)	$ 67.90		$ 67.90
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)			96.85
Range of Exercise Prices, lower limit (in dollars per share)			$ 93.64
Options Outstanding [Abstract]
Number Outstanding (in shares)	35,763		35,763
Weighted Average Remaining Contractual Life			5 years 3 months 18 days
Weighted Average Exercise Price, Options Outstanding (in dollars per share)	$ 94.27		$ 94.27
Options Exercisable [Abstract]
Number Exercisable (in shares)	11,921		11,921
Weighted Average Exercise Price, Options Exercisable (in dollars per share)	$ 94.27		$ 94.27
Employee Stock Award Plan [Member] | Fifth Price Range [Member]
Outstanding and Exercisable Stock options [Abstract]
Range of Exercise Prices, upper limit (in dollars per share)			114.11
Range of Exercise Prices, lower limit (in dollars per share)			$ 101.46
Options Outstanding [Abstract]
Number Outstanding (in shares)	37,167		37,167
Weighted Average Remaining Contractual Life			5 years 6 months
Weighted Average Exercise Price, Options Outstanding (in dollars per share)	$ 103.22		$ 103.22
Options Exercisable [Abstract]
Number Exercisable (in shares)	12,389		12,389
Weighted Average Exercise Price, Options Exercisable (in dollars per share)	$ 103.22		$ 103.22
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)			114.11
Range of Exercise Prices, lower limit (in dollars per share)			$ 31.35
Options Outstanding [Abstract]
Number Outstanding (in shares)	430,432		430,432
Weighted Average Remaining Contractual Life			4 years 6 months
Weighted Average Exercise Price, Options Outstanding (in dollars per share)	$ 71.01		$ 71.01
Aggregate Intrinsic Value, Options Outstanding	$ 1,354,000		$ 1,354,000
Options Exercisable [Abstract]
Number Exercisable (in shares)	239,518		239,518
Weighted Average Exercise Price, Options Exercisable (in dollars per share)	$ 63.56		$ 63.56
Aggregate Intrinsic Value, Options Exercisable	$ 1,354,000		$ 1,354,000
2000 Director Plan [Member]
Stock Award Plan Information [Abstract]
Term of grant			10 years
Vesting period			6 months
Shares available for future grants (in shares)	541,038		541,038
Outstanding Non-Qualified or Nonincentive Stock Awards [Roll Forward]
Outstanding at Period Start, Outstanding Non-Qualified or Nonincentive Stock Awards (in shares)			298,334
Granted, Outstanding Non-Qualified or Nonincentive Stock Awards (in shares)			0
Exercised, Outstanding Non-Qualified or Nonincentive Stock Awards (in shares)			(77,905)
Outstanding at Period End, Outstanding Non-Qualified or Nonincentive Stock Awards (in shares)	220,429		220,429
Weighted Average Exercise Price [Abstract]
Outstanding at Period Start, Weighted Average Exercise Price (in dollars per share)			$ 60.01
Granted, Weighted Average Exercise Price (in dollars per share)			0
Exercised, Weighted Average Exercise Price (in dollars per share)			47.65
Outstanding at Period End, Weighted Average Exercise Price (in dollars per share)	$ 64.37		$ 64.37
Unvested Restricted Stock Award Shares [Roll Forward]
Nonvested balance beginning of period, Unvested Restricted Stock Award Shares (in shares)			292
Granted, Unvested Restricted Stock Award Shares (in shares)			18,843
Vested, Unvested Restricted Stock Award Shares (in shares)			(858)
Nonvested balance end of period, Unvested Restricted Stock Award Shares (in shares)	18,277		18,277
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)			$ 99.52
Granted, Weighted Average Grant Date Fair Value Per Share (in dollars per share)			79.46
Vested, Weighted Average Grant Date Fair Value Per Share (in dollars per share)			86.29
Nonvested balance end of period, Weighted Average Grant Date Fair Value Per Share (in dollars per share)	$ 79.46		79.46
2000 Director Plan [Member] | First 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)			$ 29.60
Options Outstanding [Abstract]
Number Outstanding (in shares)	30,000		30,000
Weighted Average Remaining Contractual Life			2 years 2 months 12 days
Weighted Average Exercise Price, Options Outstanding (in dollars per share)	$ 33.60		$ 33.60
Options Exercisable [Abstract]
Number Exercisable (in shares)	30,000		30,000
Weighted Average Exercise Price, Options Exercisable (in dollars per share)	$ 33.60		$ 33.60
2000 Director Plan [Member] | Second 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)	71,276		71,276
Weighted Average Remaining Contractual Life			4 years 7 months 6 days
Weighted Average Exercise Price, Options Outstanding (in dollars per share)	$ 52.34		$ 52.34
Options Exercisable [Abstract]
Number Exercisable (in shares)	71,276		71,276
Weighted Average Exercise Price, Options Exercisable (in dollars per share)	$ 52.34		$ 52.34
2000 Director Plan [Member] | Third 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)	41,153		41,153
Weighted Average Remaining Contractual Life			6 years 8 months 12 days
Weighted Average Exercise Price, Options Outstanding (in dollars per share)	$ 62.34		$ 62.34
Options Exercisable [Abstract]
Number Exercisable (in shares)	41,153		41,153
Weighted Average Exercise Price, Options Exercisable (in dollars per share)	$ 62.34		$ 62.34
2000 Director Plan [Member] | Fourth Price Range [Member]
Outstanding and Exercisable Stock options [Abstract]
Range of Exercise Prices, upper limit (in dollars per share)			99.52
Range of Exercise Prices, lower limit (in dollars per share)			$ 75.17
Options Outstanding [Abstract]
Number Outstanding (in shares)	78,000		78,000
Weighted Average Remaining Contractual Life			7 years 6 months
Weighted Average Exercise Price, Options Outstanding (in dollars per share)	$ 88.28		$ 88.28
Options Exercisable [Abstract]
Number Exercisable (in shares)	78,000		78,000
Weighted Average Exercise Price, Options Exercisable (in dollars per share)	$ 88.28		$ 88.28
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)			99.52
Range of Exercise Prices, lower limit (in dollars per share)			$ 29.60
Options Outstanding [Abstract]
Number Outstanding (in shares)	220,429		220,429
Weighted Average Remaining Contractual Life			5 years 8 months 12 days
Weighted Average Exercise Price, Options Outstanding (in dollars per share)	$ 64.37		$ 64.37
Aggregate Intrinsic Value, Options Outstanding	$ 1,536,000		$ 1,536,000
Options Exercisable [Abstract]
Number Exercisable (in shares)	220,429		220,429
Weighted Average Exercise Price, Options Exercisable (in dollars per share)	$ 64.37		$ 64.37
Aggregate Intrinsic Value, Options Exercisable	$ 1,536,000		$ 1,536,000
Stock Options [Member]
Share based Compensation Plans Combined Disclosure [Abstract]
Unrecognized compensation cost related to unvested awards	3,580,000		$ 3,580,000
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	$ 19,042,000		$ 19,042,000
Weighted average period of recognition in years			3 years