Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Cash flows from operating activities:
Net loss	$ (66,611)	$ (21,797)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	906	901
Stock-based compensation	4,432	3,411
Amortization of debt issuance costs	362	346
Changes in operating assets and liabilities:
(Increase) decrease in accounts receivable	26,397	1,534
(Increase) decrease in inventory	96	74
(Increase) decrease in prepaid expenses and other current assets	(2,875)	(2,018)
Decrease in other assets	102	91
Decrease in accounts payable and other liabilities	15,137	(8,171)
Decrease in deferred revenue	0	9
Net cash provided by (used in) operating activities	(22,054)	(25,620)
Cash flows from investing activities:
Purchases of property and equipment	0	(70)
Purchases of investments	(33,222)	(87,256)
Maturities of investments	76,000	79,600
Net cash (used in) provided by investing activities	42,778	(7,726)
Cash flows from financing activities:
Repurchase of common stock	(923)	(941)
Repayment of debt borrowings, net of fees	(321)	(321)
Net cash used in financing activities	(1,244)	(1,262)
Net increase (decrease) in cash and cash equivalents	19,480	(34,608)
Cash and cash equivalents at beginning of period	36,112	80,386
Cash and cash equivalents at end of period	55,592	45,778
Supplemental disclosure of cash flow information:
Cash paid for interest	$ 3,658	$ 3,698