STOCK-BASED COMPENSATION (Details - Stock Options Rollforward) - USD ($)	6 Months Ended
	Jun. 30, 2019	May 24, 2017
Stock options, Grant Date Fair Value Valuation
Share price	$ 420.03	$ 156.70
Grant date fair value	$ 166.39
Aggregate stock options
Stock options, Shares
Outstanding at the beginning of the period (in shares)	940,533
Granted (in shares)	42,017
Exercised (in shares)	(108,418)
Forfeited (in shares)	(25,270)
Expired (in shares)	0
Outstanding at the end of the period (in shares)	848,862
Options exercisable at the end of the period (in shares)	701,319
Stock options, Weighted Average Exercise Price
Outstanding at the beginning of the period (in dollars per share)	$ 65.12
Granted (in dollars per share)	322.17
Exercised (in dollars per share)	41.36
Forfeited (in dollars per share)	334.52
Expired (in dollars per share)	0
Outstanding at the end of the period (in dollars per share)	72.86
Options exercisable at the end of the period (in dollars per share)	$ 35.97
Stock options, Weighted Average Remaining Contractual Term
Outstanding at the end of the period	4 years 9 months 25 days
Options exercisable at the end of the period	3 years 11 months 26 days
Stock options, Aggregate Intrinsic Value
Outstanding at the end of the period	$ 294,700,000
Options exercisable at the end of the period	$ 269,348,000
Stock options, Grant Date Fair Value Valuation
Expected dividend rate	0.00%
Expected volatility, minimum	51.00%
Expected volatility, maximum	55.00%
Risk-free interest rate, minimum	1.88%
Risk-free interest rate, maximum	2.55%
Expected dividends	$ 0
Performance options
Stock options, Shares
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)	(11,876)
Outstanding at the end of the period (in shares)	26,001
Options exercisable at the end of the period (in shares)	0
Stock options, 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)	308.90
Options exercisable at the end of the period (in dollars per share)	$ 0
Stock options, Weighted Average Remaining Contractual Term
Outstanding at the end of the period	1 year 29 days
Options exercisable at the end of the period	0 years
Stock options, Aggregate Intrinsic Value
Outstanding at the end of the period	$ 2,889,000
Options exercisable at the end of the period	$ 0
Market options
Stock options, Shares
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
Options exercisable at the end of the period (in shares)	0
Stock options, 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
Options exercisable at the end of the period (in dollars per share)	$ 0
Stock options, Weighted Average Remaining Contractual Term
Outstanding at the end of the period	8 years 2 months 1 day
Options exercisable at the end of the period	0 years
Stock options, Aggregate Intrinsic Value
Outstanding at the end of the period	$ 99,974,000
Options exercisable at the end of the period	$ 0
Stock options, Grant Date Fair Value Valuation
Grant date fair value	$ 230.81
Expected term	P7Y
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Volatility Rate	51.00%
Expected dividend rate	0.00%
Risk-free interest rate	2.54%
Expected dividends	$ 0
Maximum number of shared to be earned	773,945
Percentage of target number of shares	167.00%
Performance Awards Earned	481,669
Minimum | Aggregate stock options
Stock options, Grant Date Fair Value Valuation
Expected term	P5Y
Minimum | Employee stock options
Stock options, Grant Date Fair Value Valuation
Grant date fair value
Maximum | Aggregate stock options
Stock options, Grant Date Fair Value Valuation
Expected term	P6Y3M
Maximum | Employee stock options
Stock options, Grant Date Fair Value Valuation
Grant date fair value
100% over a period of one year from the grant date | Employee stock options
Stock options, Grant Date Fair Value Valuation
Vesting period	1 year
33% over a period of three years from the grant date | Employee stock options
Stock options, Grant Date Fair Value Valuation
Vesting period	3 years
25% over a period of four years from the grant date | Employee stock options
Stock options, Grant Date Fair Value Valuation
Vesting period	4 years