STOCK-BASED COMPENSATION (Restricted Stock and Restricted Stock Units Activity) (Details)	3 Months Ended
Mar. 31, 2020 $ / shares shares
Service Period \| Equity Classified Award \| Equity-Settled Award \| Restricted Stock
Number of Shares
Unvested awards outstanding at January 1, 2020	9,791
Awards granted	0
Awards vested	0
Awards forfeited/cancelled	0
Unvested awards outstanding at March 31, 2020	9,791
Weighted Average Grant Date Fair Value Per Share
Unvested awards outstanding at January 1, 2020 \| $ / shares	$ 162.96
Awards granted \| $ / shares	0
Awards vested \| $ / shares	0
Awards forfeited/cancelled \| $ / shares	0
Unvested awards outstanding at March 31, 2020 \| $ / shares	$ 162.96
Service Period \| Equity Classified Award \| Equity-Settled Award \| Restricted Stock Units
Number of Shares
Unvested awards outstanding at January 1, 2020	758,785
Awards granted	235,231
Awards vested	(273,904)
Awards forfeited/cancelled	(11,838)
Unvested awards outstanding at March 31, 2020	708,274
Weighted Average Grant Date Fair Value Per Share
Unvested awards outstanding at January 1, 2020 \| $ / shares	$ 122.48
Awards granted \| $ / shares	178.79
Awards vested \| $ / shares	104.26
Awards forfeited/cancelled \| $ / shares	128.62
Unvested awards outstanding at March 31, 2020 \| $ / shares	$ 148.13
Service Period \| Liability Classified Award \| Cash-Settled Award \| Restricted Stock Units
Number of Shares
Unvested awards outstanding at January 1, 2020	242,288
Awards granted	56,061
Awards vested	(111,966)
Awards forfeited/cancelled	(1,365)
Unvested awards outstanding at March 31, 2020	185,018
Weighted Average Grant Date Fair Value Per Share
Unvested awards outstanding at January 1, 2020 \| $ / shares	$ 105.40
Awards granted \| $ / shares	181.59
Awards vested \| $ / shares	90.08
Awards forfeited/cancelled \| $ / shares	111.01
Unvested awards outstanding at March 31, 2020 \| $ / shares	$ 137.72
Performance Target \| Equity Classified Award \| Equity-Settled Award \| Restricted Stock
Number of Shares
Unvested awards outstanding at January 1, 2020	9,393
Awards granted	0
Unvested awards outstanding at March 31, 2020	9,393
Weighted Average Grant Date Fair Value Per Share
Unvested awards outstanding at January 1, 2020 \| $ / shares	$ 165.87
Awards granted \| $ / shares	0
Unvested awards outstanding at March 31, 2020 \| $ / shares	$ 165.87
Performance Target \| Equity Classified Award \| Equity-Settled Award \| Restricted Stock Units
Number of Shares
Unvested awards outstanding at January 1, 2020	0
Awards granted	24,836
Unvested awards outstanding at March 31, 2020	24,836
Weighted Average Grant Date Fair Value Per Share
Unvested awards outstanding at January 1, 2020 \| $ / shares	$ 0
Awards granted \| $ / shares	177.81
Unvested awards outstanding at March 31, 2020 \| $ / shares	$ 177.81
2020 Acquisition \| Service Period \| Equity Classified Award \| Equity-Settled Award \| Restricted Stock Units
Number of Shares
Awards granted	11,927
2020 Acquisition \| Service Period \| Liability Classified Award \| Cash-Settled Award \| Restricted Stock Units
Number of Shares
Awards granted	6,054
2019 Acquisitions \| Service Period \| Equity Classified Award \| Equity-Settled Award \| Restricted Stock Units
Number of Shares
Awards granted	5,793
2019 Acquisitions \| Performance Target \| Equity Classified Award \| Equity-Settled Award \| Restricted Stock Units
Number of Shares
Awards granted	24,836

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

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-Name Accounting Standards Codification
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-Section 50
-Paragraph 2
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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.

+ References

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A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

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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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Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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The number of equity-based payment instruments, excluding stock (or unit) options, that vested during the reporting period.

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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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