STOCK AWARD PLANS (Details) (USD $) | 3 Months Ended | 6 Months Ended |
Jun. 30, 2014 | Jun. 30, 2013 | Jun. 30, 2014 | Jun. 30, 2013 |
STOCK AWARD PLANS [Abstract] | ' | ' | ' | ' |
Compensation cost | $3,120,000 | $2,927,000 | $5,273,000 | $5,061,000 |
Income tax benefit | 1,182,000 | 1,106,000 | 1,998,000 | 1,913,000 |
Share based Compensation Plans Combined Disclosure [Abstract] | ' | ' | ' | ' |
Intrinsic value of stock options exercised | ' | ' | 11,456,000 | 3,342,000 |
Tax benefit from stock options exercised | ' | ' | 4,342,000 | 1,263,000 |
Intrinsic value of restricted stock vesting | ' | ' | 13,949,000 | 9,230,000 |
Tax benefit from restricted stock vesting | ' | ' | 5,287,000 | 3,489,000 |
Fair value of options vested | ' | ' | 2,076,000 | 1,714,000 |
Fair value of restricted stock vested | ' | ' | 13,949,000 | 9,230,000 |
Fair value of stock options granted (in dollars per share) | ' | ' | $36.05 | $25.07 |
Fair value of stock options granted | ' | ' | 4,226,000 | 4,125,000 |
Fair Value Assumptions [Abstract] | ' | ' | ' | ' |
Dividend yield (in hundredths) | ' | ' | 0.00% | 0.00% |
Average risk-free interest rate (in hundredths) | ' | ' | 2.00% | 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 |
Fifth 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) | 2,535,165 | ' | 2,535,165 | ' |
Outstanding Non-Qualified or Nonincentive Stock Awards [Roll Forward] | ' | ' | ' | ' |
Outstanding at Period Start, Outstanding Non-Qualified or Nonincentive Stock Awards (in shares) | ' | ' | 379,604 | ' |
Granted, Outstanding Non-Qualified or Nonincentive Stock Awards (in shares) | ' | ' | 75,204 | ' |
Exercised, Outstanding Non-Qualified or Nonincentive Stock Awards (in shares) | ' | ' | -115,167 | ' |
Forfeited, Outstanding Non-Qualified or Nonincentive Stock Awards (in shares) | ' | ' | -12,576 | ' |
Outstanding at Period End, Outstanding Non-Qualified or Nonincentive Stock Awards (in shares) | 327,065 | ' | 327,065 | ' |
Weighted Average Exercise Price [Abstract] | ' | ' | ' | ' |
Outstanding at Period Start, Weighted Average Exercise Price (in dollars per share) | ' | ' | $55.42 | ' |
Granted, Weighted Average Exercise Price (in dollars per share) | ' | ' | $98.91 | ' |
Exercised, Weighted Average Exercise Price (in dollars per share) | ' | ' | $41.45 | ' |
Forfeited, Weighted Average Exercise Price (in dollars per share) | ' | ' | $68.89 | ' |
Outstanding at Period End, Weighted Average Exercise Price (in dollars per share) | $69.82 | ' | $69.82 | ' |
Unvested Restricted Stock Award Shares [Roll Forward] | ' | ' | ' | ' |
Nonvested balance beginning of period, Unvested Restricted Stock Award Shares (in shares) | ' | ' | 399,278 | ' |
Granted, Unvested Restricted Stock Award Shares (in shares) | ' | ' | 97,706 | ' |
Vested, Unvested Restricted Stock Award Shares (in shares) | ' | ' | -141,382 | ' |
Forfeited, Unvested Restricted Stock Award Shares (in shares) | ' | ' | -27,880 | ' |
Nonvested balance end of period, Unvested Restricted Stock Award Shares (in shares) | 327,722 | ' | 327,722 | ' |
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) | ' | ' | $54.92 | ' |
Granted, Weighted Average Grant Date Fair Value Per Share (in dollars per share) | ' | ' | $97.46 | ' |
Vested, Weighted Average Grant Date Fair Value Per Share (in dollars per share) | ' | ' | $45.60 | ' |
Forfeited, Weighted Average Grant Date Fair Value Per Share (in dollars per share) | ' | ' | $61.82 | ' |
Nonvested balance end of period, Weighted Average Grant Date Fair Value Per Share (in dollars per share) | $71.04 | ' | $71.04 | ' |
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 (in years) | ' | ' | '2 years 7 months 6 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) | 58,229 | ' | 58,229 | ' |
Weighted Average Remaining Contractual Life (in years) | ' | ' | '3 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) | 58,229 | ' | 58,229 | ' |
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) | ' | ' | $70.65 | ' |
Range of Exercise Prices, lower limit (in dollars per share) | ' | ' | $65.28 | ' |
Options Outstanding [Abstract] | ' | ' | ' | ' |
Number Outstanding (in shares) | 174,755 | ' | 174,755 | ' |
Weighted Average Remaining Contractual Life (in years) | ' | ' | '5 years 1 month 6 days | ' |
Weighted Average Exercise Price, Options Outstanding (in dollars per share) | $68.37 | ' | $68.37 | ' |
Options Exercisable [Abstract] | ' | ' | ' | ' |
Number Exercisable (in shares) | 85,455 | ' | 85,455 | ' |
Weighted Average Exercise Price, Options Exercisable (in dollars per share) | $67.56 | ' | $67.56 | ' |
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) | ' | ' | $86.96 | ' |
Options Outstanding [Abstract] | ' | ' | ' | ' |
Number Outstanding (in shares) | 37,730 | ' | 37,730 | ' |
Weighted Average Remaining Contractual Life (in years) | ' | ' | '6 years 7 months 6 days | ' |
Weighted Average Exercise Price, Options Outstanding (in dollars per share) | $93.89 | ' | $93.89 | ' |
Options Exercisable [Abstract] | ' | ' | ' | ' |
Number Exercisable (in shares) | 0 | ' | 0 | ' |
Weighted Average Exercise Price, Options Exercisable (in dollars per share) | $0 | ' | $0 | ' |
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) | 39,441 | ' | 39,441 | ' |
Weighted Average Remaining Contractual Life (in years) | ' | ' | '6 years 8 months 12 days | ' |
Weighted Average Exercise Price, Options Outstanding (in dollars per share) | $103.12 | ' | $103.12 | ' |
Options Exercisable [Abstract] | ' | ' | ' | ' |
Number Exercisable (in shares) | 0 | ' | 0 | ' |
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) | 327,065 | ' | 327,065 | ' |
Weighted Average Remaining Contractual Life (in years) | ' | ' | '5 years 1 month 6 days | ' |
Weighted Average Exercise Price, Options Outstanding (in dollars per share) | $69.82 | ' | $69.82 | ' |
Aggregate Intrinsic Value, Options Outstanding | 15,477,000 | ' | 15,477,000 | ' |
Options Exercisable [Abstract] | ' | ' | ' | ' |
Number Exercisable (in shares) | 160,594 | ' | 160,594 | ' |
Weighted Average Exercise Price, Options Exercisable (in dollars per share) | $56.35 | ' | $56.35 | ' |
Aggregate Intrinsic Value, Options Exercisable | 9,762,000 | ' | 9,762,000 | ' |
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) | 559,881 | ' | 559,881 | ' |
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) | ' | ' | 320,322 | ' |
Exercised, Outstanding Non-Qualified or Nonincentive Stock Awards (in shares) | ' | ' | 42,000 | ' |
Outstanding at Period End, Outstanding Non-Qualified or Nonincentive Stock Awards (in shares) | -63,988 | ' | -63,988 | ' |
Weighted Average Exercise Price [Abstract] | ' | ' | ' | ' |
Outstanding at Period Start, Weighted Average Exercise Price (in dollars per share) | ' | ' | $50.64 | ' |
Exercised, Weighted Average Exercise Price (in dollars per share) | ' | ' | $99.52 | ' |
Outstanding at Period End, Weighted Average Exercise Price (in dollars per share) | $39.08 | ' | $39.08 | ' |
Unvested Restricted Stock Award Shares [Roll Forward] | ' | ' | ' | ' |
Nonvested balance beginning of period, Unvested Restricted Stock Award Shares (in shares) | ' | ' | 384 | ' |
Granted, Unvested Restricted Stock Award Shares (in shares) | ' | ' | 8,160 | ' |
Vested, Unvested Restricted Stock Award Shares (in shares) | ' | ' | -672 | ' |
Nonvested balance end of period, Unvested Restricted Stock Award Shares (in shares) | 7,872 | ' | 7,872 | ' |
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) | ' | ' | $75.65 | ' |
Granted, Weighted Average Grant Date Fair Value Per Share (in dollars per share) | ' | ' | $99.52 | ' |
Vested, Weighted Average Grant Date Fair Value Per Share (in dollars per share) | ' | ' | $85.88 | ' |
Nonvested balance end of period, Weighted Average Grant Date Fair Value Per Share (in dollars per share) | $99.52 | ' | $99.52 | ' |
2000 Director Plan [Member] | First 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) | 30,000 | ' | 30,000 | ' |
Weighted Average Remaining Contractual Life (in years) | ' | ' | '2 years 4 months 24 days | ' |
Weighted Average Exercise Price, Options Outstanding (in dollars per share) | $25.87 | ' | $25.87 | ' |
Options Exercisable [Abstract] | ' | ' | ' | ' |
Number Exercisable (in shares) | 30,000 | ' | 30,000 | ' |
Weighted Average Exercise Price, Options Exercisable (in dollars per share) | $25.87 | ' | $25.87 | ' |
2000 Director Plan [Member] | Second 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) | 32,048 | ' | 32,048 | ' |
Weighted Average Remaining Contractual Life (in years) | ' | ' | '1 year 9 months 18 days | ' |
Weighted Average Exercise Price, Options Outstanding (in dollars per share) | $36.09 | ' | $36.09 | ' |
Options Exercisable [Abstract] | ' | ' | ' | ' |
Number Exercisable (in shares) | 32,048 | ' | 32,048 | ' |
Weighted Average Exercise Price, Options Exercisable (in dollars per share) | $36.09 | ' | $36.09 | ' |
2000 Director Plan [Member] | Third 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) | 91,022 | ' | 91,022 | ' |
Weighted Average Remaining Contractual Life (in years) | ' | ' | '4 years 8 months 12 days | ' |
Weighted Average Exercise Price, Options Outstanding (in dollars per share) | $51.87 | ' | $51.87 | ' |
Options Exercisable [Abstract] | ' | ' | ' | ' |
Number Exercisable (in shares) | 91,022 | ' | 91,022 | ' |
Weighted Average Exercise Price, Options Exercisable (in dollars per share) | $51.87 | ' | $51.87 | ' |
2000 Director Plan [Member] | Fourth 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) | 54,306 | ' | 54,306 | ' |
Weighted Average Remaining Contractual Life (in years) | ' | ' | '6 years 3 months 18 days | ' |
Weighted Average Exercise Price, Options Outstanding (in dollars per share) | $62.37 | ' | $62.37 | ' |
Options Exercisable [Abstract] | ' | ' | ' | ' |
Number Exercisable (in shares) | 54,306 | ' | 54,306 | ' |
Weighted Average Exercise Price, Options Exercisable (in dollars per share) | $62.37 | ' | $62.37 | ' |
2000 Director Plan [Member] | Fifth Price Range [Member] | ' | ' | ' | ' |
Options Outstanding [Abstract] | ' | ' | ' | ' |
Number Outstanding (in shares) | 90,958 | ' | 90,958 | ' |
Weighted Average Remaining Contractual Life (in years) | ' | ' | '7 years 8 months 12 days | ' |
Weighted Average Exercise Price, Options Outstanding (in dollars per share) | $86.41 | ' | $86.41 | ' |
Options Exercisable [Abstract] | ' | ' | ' | ' |
Number Exercisable (in shares) | 48,958 | ' | 48,958 | ' |
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) | ' | ' | $99.52 | ' |
Range of Exercise Prices, lower limit (in dollars per share) | ' | ' | $20.28 | ' |
Options Outstanding [Abstract] | ' | ' | ' | ' |
Number Outstanding (in shares) | 298,334 | ' | 298,334 | ' |
Weighted Average Remaining Contractual Life (in years) | ' | ' | '5 years 4 months 24 days | ' |
Weighted Average Exercise Price, Options Outstanding (in dollars per share) | $60.01 | ' | $60.01 | ' |
Aggregate Intrinsic Value, Options Outstanding | 17,045,000 | ' | 17,045,000 | ' |
Options Exercisable [Abstract] | ' | ' | ' | ' |
Number Exercisable (in shares) | 256,334 | ' | 256,334 | ' |
Weighted Average Exercise Price, Options Exercisable (in dollars per share) | $53.53 | ' | $53.53 | ' |
Aggregate Intrinsic Value, Options Exercisable | 16,305,000 | ' | 16,305,000 | ' |
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] | ' | ' | ' | ' |
Unrecognized compensation cost related to unvested awards | 4,903,000 | ' | 4,903,000 | ' |
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 | $20,802,000 | ' | $20,802,000 | ' |
Weighted average period of recognition in years | ' | ' | '3 years 1 month 6 days | ' |