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Period over which grantee's right to exercise award under share-based payment arrangement is no longer contingent on satisfaction of service or performance condition, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days. Includes, but is not limited to, combination of market, performance or service condition.

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The estimated amount of dividends to be paid to holders of the underlying shares (expected dividends) over the option's term. Dividends are taken into account because payment of dividends to shareholders reduces the fair value of the underlying shares, and option holders generally do not receive dividends.

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The estimated dividend rate (a percentage of the share price) to be paid (expected dividends) to holders of the underlying shares over the option's term.

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The estimated measure of the maximum percentage by which a share price is expected to fluctuate during a period. Volatility also may be defined as a probability-weighted measure of the dispersion of returns about the mean. The volatility of a share price is the standard deviation of the continuously compounded rates of return on the share over a specified period. That is the same as the standard deviation of the differences in the natural logarithms of the stock prices plus dividends, if any, over the period.

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No definition available.

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The estimated measure of the minimum percentage by which a share price is expected to fluctuate during a period. Volatility also may be defined as a probability-weighted measure of the dispersion of returns about the mean. The volatility of a share price is the standard deviation of the continuously compounded rates of return on the share over a specified period. That is the same as the standard deviation of the differences in the natural logarithms of the stock prices plus dividends, if any, over the period.

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The maximum risk-free interest rate assumption that is used in valuing an option on its own shares.

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The minimum risk-free interest rate assumption that is used in valuing an option on its own shares.

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The number of shares into which fully or partially vested stock options outstanding as of the balance sheet date can be currently converted under the option plan.

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The weighted-average price as of the balance sheet date at which grantees can acquire the shares reserved for issuance on vested portions of options outstanding and currently exercisable under the stock option plan.

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Number of options or other stock instruments for which the right to exercise has lapsed under the terms of the plan agreements.

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The number of shares under options that were cancelled during the reporting period as a result of occurrence of a terminating event specified in contractual agreements pertaining to the stock option plan.

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Gross number of share options (or share units) granted during the period.

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Amount by which the current fair value of the underlying stock exceeds the exercise price of options outstanding.

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Number of options outstanding, including both vested and non-vested options.

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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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Weighted average price at which grantees can acquire the shares reserved for issuance under the stock option plan.

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Weighted average price at which option holders acquired shares when converting their stock options into shares.

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Weighted average price at which grantees could have acquired the underlying shares with respect to stock options of the plan that expired.

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Weighted average per share amount at which grantees can acquire shares of common stock by exercise of options.

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Price of a single share of a number of saleable stocks of a company.

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Expected term of award under share-based payment arrangement, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days.

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Amount of difference between fair value of the underlying shares reserved for issuance and exercise price of vested portions of options outstanding and currently exercisable.

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STOCK-BASED COMPENSATION (Schedules - Stock Options) (Details) - USD ($)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	May 24, 2017
Aggregate Intrinsic Value
Share price (in dollars per share)	$ 303.44			$ 156.70
Stock Options, One
Number of Options
Outstanding at the beginning of the period (in shares)	940,533
Granted (in shares)	43,704
Exercised (in shares)	(167,686)
Forfeited (in shares)	(38,680)
Expired (in shares)	0
Outstanding at the end of the period (in shares)	777,871	940,533
Options exercisable at the end of the period (in shares)	668,976
Weighted Average Exercise Price
Outstanding at the beginning of the period (in dollars per share)	$ 65.12
Granted (in dollars per share)	323.82
Exercised (in dollars per share)	52.08
Forfeited (in dollars per share)	318.36
Expired (in dollars per share)	0
Outstanding at the end of the period (in dollars per share)	69.87	$ 65.12
Options exercisable at the end of the period (in dollars per share)	$ 39.73
Weighted Average Remaining Contractual Term
Outstanding at the end of the period	4 years 3 months 10 days
Options exercisable at the end of the period	3 years 7 months 9 days
Aggregate Intrinsic Value
Outstanding at the end of the period	$ 182,809,000
Options exercisable at the end of the period	176,710,000
Divdends	$ 0	$ 0	$ 0
Weighted average assumptions
Dividend yield	0.00%	0.00%	0.00%
Expected Volatility Rate, Minimum	51.00%	50.00%	51.00%
Expected Volatility Rate, Maximum	55.00%	53.00%	52.00%
Risk Free Interest Rate, Minimum	1.46%	2.33%	1.74%
Risk Free Interest Rate, Maximum	2.55%	3.06%	2.24%
Stock Options, Two
Number of Options
Outstanding at the beginning of the period (in shares)	37,877
Granted (in shares)	0
Exercised (in shares)	0
Forfeited (in shares)	0
Expired (in shares)	(37,877)
Outstanding at the end of the period (in shares)	0	37,877
Options exercisable at the end of the period (in shares)	0
Weighted Average Exercise Price
Outstanding at the beginning of the period (in dollars per share)	$ 308.90
Granted (in dollars per share)	0
Exercised (in dollars per share)	0
Forfeited (in dollars per share)	0
Expired (in dollars per share)	308.90
Outstanding at the end of the period (in dollars per share)	0	$ 308.90
Options exercisable at the end of the period (in dollars per share)	$ 0
Weighted Average Remaining Contractual Term
Outstanding at the end of the period	0 years
Options exercisable at the end of the period	0 years
Aggregate Intrinsic Value
Outstanding at the end of the period	$ 0
Options exercisable at the end of the period	$ 0
Weighted average assumptions
Dividend yield		0.00%
Expected Volatility Rate, Minimum			51.00%
Expected Volatility Rate, Maximum			51.00%
Risk Free Interest Rate, Minimum			2.16%
Risk Free Interest Rate, Maximum			2.23%
Share-based Payment Arrangement
Aggregate Intrinsic Value
Divdends			$ 0
Performance Options
Number of Options
Outstanding at the beginning of the period (in shares)	447,193
Granted (in shares)	16,247
Exercised (in shares)	0
Forfeited (in shares)	0
Expired (in shares)	0
Outstanding at the end of the period (in shares)	463,440	447,193
Options exercisable at the end of the period (in shares)	0
Weighted Average Exercise Price
Outstanding at the beginning of the period (in dollars per share)	$ 200.51
Granted (in dollars per share)	308.96
Exercised (in dollars per share)	0
Forfeited (in dollars per share)	0
Expired (in dollars per share)	0
Outstanding at the end of the period (in dollars per share)	204.31	$ 200.51
Options exercisable at the end of the period (in dollars per share)	$ 0
Weighted Average Remaining Contractual Term
Outstanding at the end of the period	7 years 8 months 1 day
Options exercisable at the end of the period	0 years
Aggregate Intrinsic Value
Outstanding at the end of the period	$ 48,178,000
Options exercisable at the end of the period	0
Divdends	$ 0	$ 0	$ 0
Weighted average assumptions
Expected Volatility Rate, Minimum	51.00%	50.00%	50.00%
Expected Volatility Rate, Maximum	51.00%	50.00%	50.00%
Risk Free Interest Rate, Minimum	2.54%	2.38%	2.12%
Risk Free Interest Rate, Maximum	2.54%	2.81%	2.12%
Minimum \| Stock Options, One
Weighted average assumptions
Expected Term	5 years	5 years	5 years
Minimum \| Stock Options, Two
Weighted average assumptions
Expected Term			5 years 6 months
Vesting period			1 year 2 months 12 days
Minimum \| Performance Options
Weighted average assumptions
Expected Term	7 years	7 years	7 years 6 months
Maximum \| Stock Options, One
Weighted average assumptions
Expected Term	6 years 3 months	6 years 8 months 15 days	7 years
Maximum \| Stock Options, Two
Weighted average assumptions
Expected Term			6 years
Vesting period			2 years 2 months 12 days
Maximum \| Performance Options
Weighted average assumptions
Expected Term	7 years	7 years 1 month 24 days	7 years 6 months