DEBT - Convertible Note Hedge and Warrant Transactions (Details) - USD ($) $ / shares in Units, $ in Thousands, shares in Millions			9 Months Ended
	Jul. 24, 2020	May 31, 2017	Sep. 30, 2021	Sep. 30, 2020	Jul. 21, 2020	May 24, 2017
Debt Instrument [Line Items]
Payment of convertible note hedge transactions			$ 0	$ 124,200
Share price (in dollars per share)			$ 139.83
Proceeds from the sale of warrants related to the Convertible Senior Notes			$ 0	61,180
Termination of convertible note hedge on the 0.625% Convertible Senior Notes			0	109,881
Payments for repurchase of warrants			0	$ 94,292
2020 Hedge and Warrants
Debt Instrument [Line Items]
Net proceeds from debt used to pay for the cost of the hedge	$ 63,000
Payment of convertible note hedge transactions	$ 124,200
Number of shares covered by the hedge transactions	1.2
Initial conversion price per share (in dollars per share)	$ 461.19
Strike price of warrants sold (in dollars per share)	$ 709.52
Premium of warrant strike price over sales price of common stock	100.00%
Share price (in dollars per share)					$ 354.76
Proceeds from the sale of warrants related to the Convertible Senior Notes	$ 61,200
2017 Hedge and Warrants
Debt Instrument [Line Items]
Net proceeds from debt used to pay for the cost of the hedge		$ 18,100
Payment of convertible note hedge transactions		$ 61,500
Number of shares covered by the hedge transactions	0.8	1.4
Initial conversion price per share (in dollars per share)		$ 207.63
Strike price of warrants sold (in dollars per share)		$ 266.39
Premium of warrant strike price over sales price of common stock		70.00%
Share price (in dollars per share)						$ 156.70
Proceeds from the sale of warrants related to the Convertible Senior Notes		$ 43,400
Termination of convertible note hedge on the 0.625% Convertible Senior Notes			109,900
Payments for repurchase of warrants			$ 94,300
Proceeds from hedge and warrants	$ 15,600