CONDENSED CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY - USD ($) $ in Thousands	Total	Common stock and paid-in capital	Accumulated deficit	Accumulated other comprehensive income (loss)
Balance, beginning of period at Dec. 31, 2019		$ 458,316	$ (185,181)	$ (923)
Issuance of common stock from exercise of equity awards and employee stock purchase plan		4,846
Payment of withholding taxes related to net share settlement of equity awards		(43,652)
Equity component of convertible notes issued, net of tax		116,300
Cost of convertible notes hedge related to the convertible notes issued, net of tax		(117,108)
Sale of warrants related to the convertible notes issued		96,351
Equity component of partial settlement of convertible notes		0
Cost of reacquired equity component on partial settlement of convertible notes		0
Stock-based compensation expense		19,815
Net income (loss)	$ 21,642		21,642
Repurchase of common stock			0
Foreign currency translation adjustments	(230)			(230)
Balance, end of period at Jun. 30, 2020	370,176	534,868	(163,539)	(1,153)
Balance, beginning of period at Mar. 31, 2020		433,543	(116,245)	(1,091)
Issuance of common stock from exercise of equity awards and employee stock purchase plan		2,867
Payment of withholding taxes related to net share settlement of equity awards		(9,385)
Equity component of convertible notes issued, net of tax		116,300
Cost of convertible notes hedge related to the convertible notes issued, net of tax		(117,108)
Sale of warrants related to the convertible notes issued		96,351
Equity component of partial settlement of convertible notes		0
Cost of reacquired equity component on partial settlement of convertible notes		0
Stock-based compensation expense		12,300
Net income (loss)	(47,294)		(47,294)
Repurchase of common stock			0
Foreign currency translation adjustments	(62)			(62)
Balance, end of period at Jun. 30, 2020	370,176	534,868	(163,539)	(1,153)
Balance, beginning of period at Dec. 31, 2020	483,993	534,745	(51,186)	434
Issuance of common stock from exercise of equity awards and employee stock purchase plan		3,642
Payment of withholding taxes related to net share settlement of equity awards		(16,998)
Equity component of convertible notes issued, net of tax		207,970
Cost of convertible notes hedge related to the convertible notes issued, net of tax		(213,322)
Sale of warrants related to the convertible notes issued		220,800
Equity component of partial settlement of convertible notes		(966,557)
Cost of reacquired equity component on partial settlement of convertible notes		962,176
Stock-based compensation expense		30,156
Net income (loss)	71,049		71,049
Repurchase of common stock			(200,000)
Foreign currency translation adjustments	1,490			1,490
Balance, end of period at Jun. 30, 2021	584,399	762,612	(180,137)	1,924
Balance, beginning of period at Mar. 31, 2021		751,689	(19,488)	640
Issuance of common stock from exercise of equity awards and employee stock purchase plan		3,428
Payment of withholding taxes related to net share settlement of equity awards		(7,813)
Equity component of convertible notes issued, net of tax		8
Cost of convertible notes hedge related to the convertible notes issued, net of tax		0
Sale of warrants related to the convertible notes issued		0
Equity component of partial settlement of convertible notes		(74)
Cost of reacquired equity component on partial settlement of convertible notes		62
Stock-based compensation expense		15,312
Net income (loss)	39,351		39,351
Repurchase of common stock			(200,000)
Foreign currency translation adjustments	1,284			1,284
Balance, end of period at Jun. 30, 2021	$ 584,399	$ 762,612	$ (180,137)	$ 1,924