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EMPLOYEE BENEFIT PLANS (Restrictive Stock Award Activity) (Details)	12 Months Ended
	Dec. 31, 2019 $ / shares shares
Performance Based RSAs Without Market Condition
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Unvested restricted stock at beginning of period (in shares) | shares	304,161
Granted (in shares) | shares	115,722
Vested (in shares) | shares	(134,361)
Canceled (in shares) | shares	(18,303)
Unvested restricted stock at end of period (in shares) | shares	267,219
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Additional Disclosures [Abstract]
Unvested restricted stock at beginning of period (in dollars per share)	$ 272.95
Granted (in dollars per share)	456.51
Vested (in dollars per share)	241.65
Canceled (in dollars per share)	315.39
Unvested restricted stock at end of period (in dollars per share)	$ 365.27
Performance-based RSAs - with Market Condition
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Unvested restricted stock at beginning of period (in shares) | shares	76,320
Vested (in shares) | shares	(23,040)
Canceled (in shares) | shares	0
Unvested restricted stock at end of period (in shares) | shares	89,280
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Additional Disclosures [Abstract]
Unvested restricted stock at beginning of period (in dollars per share)	$ 193.44
Granted (in dollars per share)	429.63
Vested (in dollars per share)	184.97
Canceled (in dollars per share)	0
Unvested restricted stock at end of period (in dollars per share)	$ 290.87

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The number of equity-based payment instruments, excluding stock (or unit) options, that were forfeited during the reporting period.

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Weighted average fair value as of the grant date of equity-based award plans other than stock (unit) option plans that were not exercised or put into effect as a result of the occurrence of a terminating event.

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The number of grants made during the period on other than stock (or unit) option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, performance target plan).

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The weighted average fair value at grant date for nonvested equity-based awards issued during the period on other than stock (or unit) option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, performance target plan).

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The number of non-vested equity-based payment instruments, excluding stock (or unit) options, that validly exist and are outstanding as of the balance sheet date.

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Per share or unit weighted-average fair value of nonvested award under share-based payment arrangement. Excludes share and unit options.

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The weighted average fair value as of grant date pertaining to an equity-based award plan other than a stock (or unit) option plan for which the grantee gained the right during the reporting period, by satisfying service and performance requirements, to receive or retain shares or units, other instruments, or cash in accordance with the terms of the arrangement.

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