DEBT - Convertible Senior Notes Narrative (Details)			3 Months Ended
	Jul. 24, 2020 USD ($) day $ / shares Rate shares	May 31, 2017 USD ($) day Rate	Mar. 31, 2022 USD ($) day Rate	Mar. 31, 2021 USD ($)	Sep. 30, 2020 USD ($)	Dec. 31, 2021 USD ($)	May 31, 2017	May 31, 2017 shares	May 31, 2017 $ / shares	May 31, 2017 Rate
Debt Instrument [Line Items]
Amortization of debt issuance costs			$ 2,467,000	$ 1,275,000
Amortization of debt discount			879,000	7,346,000
2025 Convertible Notes
Debt Instrument [Line Items]
Initial conversion rate, shares per $1,000 principal amount of notes | shares	2.1683
Initial conversion price per share (in dollars per share) | $ / shares	$ 461.19
Cash repurchase at a price equal to the principal amount of the notes, percentage | Rate	100.00%
Nonconvertible debt borrowing rate at the date of issuance | Rate	5.30%
Debt component of the principal amount	$ 455,600,000
Equity component of the principal amount	119,400,000
Financing costs	15,100,000
Debt issuance costs	12,000,000		10,019,000			$ 8,855,000
Debt issuance costs, equity component	$ 3,100,000
Interest expense			1,500,000	6,800,000
Interest expense recognized associated with the coupon rate			700,000	700,000
Annual interest rate on convertible senior notes	0.50%
Amortization of debt issuance costs			$ 800,000	600,000
Amortization of debt discount				5,500,000
2025 Convertible Notes | Conversion option one
Debt Instrument [Line Items]
Threshold trading days | day	20
Threshold consecutive trading days | day	30		30
Conversion rate, sales price of common stock as a percentage of the conversion price | Rate	130.00%		130.00%
2025 Convertible Notes | Conversion option two
Debt Instrument [Line Items]
Threshold trading days | day	5
Threshold consecutive trading days | day	5
Conversion rate | Rate	98.00%
2025 Convertible Notes | Convertible Debt
Debt Instrument [Line Items]
Aggregate principal amount	$ 575,000,000
Stated interest rate	0.50%		0.50%
Fair value			$ 471,500,000
2025 Notes Under 13-day Purchase Option | Convertible Debt
Debt Instrument [Line Items]
Aggregate principal amount	$ 75,000,000
2022 Convertible Notes
Debt Instrument [Line Items]
Aggregate principal amount		$ 300,000,000
Stated interest rate | Rate										0.625%
Initial conversion rate, shares per $1,000 principal amount of notes | shares								4.8163
Initial conversion price per share (in dollars per share) | $ / shares									$ 207.63
Cash repurchase at a price equal to the principal amount of the notes, percentage | Rate		100.00%
Nonconvertible debt borrowing rate at the date of issuance							5.36%
Debt component of the principal amount		$ 238,400,000
Equity component of the principal amount		61,600,000
Financing costs		9,300,000
Debt issuance costs		7,400,000	175,000			$ 391,000
Debt issuance costs, equity component		$ 1,900,000
Interest expense			500,000	2,300,000
Interest expense recognized associated with the coupon rate			300,000	300,000
Annual interest rate on convertible senior notes							0.625%			0.625%
Amortization of debt issuance costs			200,000	200,000
Amortization of debt discount				$ 1,800,000
Fair value			$ 168,400,000
Repayments of convertible debt	234,000,000
Debt repurchase amount	130,300,000
Debt repurchased amount, accrued interest	100,000
Extinguishment of debt	126,000,000
Repurchase of 0.625% Convertible Senior Notes, net	$ 107,900,000
Loss on extinguishment of debt					$ 7,800,000
2022 Convertible Notes | Conversion option one
Debt Instrument [Line Items]
Threshold trading days | day		20
Threshold consecutive trading days | day		30
Conversion rate, sales price of common stock as a percentage of the conversion price | Rate		130.00%
2022 Convertible Notes | Conversion option two
Debt Instrument [Line Items]
Threshold trading days | day		5
Threshold consecutive trading days | day		5
Conversion rate | Rate		98.00%
2022 Convertible Notes | Convertible Debt
Debt Instrument [Line Items]
Stated interest rate			0.625%