CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019
Cash flows from operating activities:
Net income	$ 61,004	$ 44,482
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	12,750	11,551
Provision for doubtful accounts	254	408
Non-cash interest expense	13,516	4,173
Financing fees on extinguishment of debt	0	2,152
Fees paid for repurchase and exchange of convertible notes due 2023	0	6,000
Stock-based compensation	34,214	14,000
Change in fair value of derivatives	44,348	0
Deferred income taxes	(14,507)	0
Changes in operating assets and liabilities:
Accounts receivable	23,533	(56,139)
Inventory	(5,479)	(13,964)
Prepaid expenses and other assets	(10,451)	(8,634)
Accounts payable, accrued and other liabilities	(9,200)	18,656
Warranty obligations	6,681	3,330
Deferred revenues	(24,509)	10,781
Net cash provided by operating activities	132,154	36,796
Cash flows from investing activities:
Purchases of property and equipment	(11,707)	(7,368)
Net cash used in investing activities	(11,707)	(7,368)
Cash flows from financing activities:
Issuance of convertible notes, net of issuance costs	312,420	127,481
Purchase of convertible note hedges	(89,056)	(36,313)
Sale of warrants	71,552	29,819
Fees paid for repurchase and exchange of convertible notes due 2023	0	(6,000)
Principal payments and financing fees on debt	(2,269)	(45,658)
Proceeds from exercise of equity awards and employee stock purchase plan	4,708	2,925
Payment of withholding taxes related to net share settlement of equity awards	(52,042)	(4,438)
Net cash provided by financing activities	245,313	67,816
Effect of exchange rate changes on cash and cash equivalents	(77)	(435)
Net increase in cash and cash equivalents	365,683	96,809
Cash, cash equivalents and restricted cash—Beginning of period	296,109	106,237
Cash and cash equivalents—End of period	661,792	203,046
Supplemental disclosures of non-cash investing and financing activities:
Purchases of fixed assets included in accounts payable	2,132	926
Accrued interest payable unpaid upon exchange of convertible notes due 2023	$ 0	$ 833