Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017
Cash flows from operating activities:
Net loss	$ (76,781)	$ (69,950)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	1,853	1,552
Increase in fair value of Symphony Icon, Inc. purchase liability	0	2,101
Stock-based compensation	5,972	4,634
Amortization of debt issuance costs	592	254
Deferred tax benefit	0	(8,652)
Loss on disposal of property and equipment	0	(2)
Changes in operating assets and liabilities:
Decrease in accounts receivable	419	2,478
Increase in inventory	(194)	(811)
(Increase) decrease in prepaid expenses and other current assets	481	(6,296)
Decrease in other assets	0	33
Decrease in accounts payable and other liabilities	(6,644)	(22,269)
Decrease in deferred revenue	(24,996)	(20,797)
Net cash used in operating activities	(99,298)	(117,721)
Cash flows from investing activities:
Purchases of property and equipment	(55)	(163)
Purchases of investments	(49,638)	(59,989)
Maturities of investments	104,123	159,393
Net cash provided by investing activities	54,430	99,241
Cash flows from financing activities:
Proceeds from issuance of common stock	392	5,427
Repurchase of common stock	(972)	(1,679)
Repayment of debt borrowings	(1,169)	(1,162)
Net cash (used in) provided by financing activities	(1,749)	2,586
Net decrease in cash and cash equivalents	(46,617)	(15,894)
Cash and cash equivalents at beginning of period	61,661	46,600
Cash and cash equivalents at end of period	15,044	30,706
Supplemental disclosure of cash flow information:
Cash paid for interest	6,726	2,956
Supplemental disclosure of non-cash investing and financing activities:
Common stock issued in satisfaction of Symphony Icon payment obligation	0	10,499
Unrealized loss on investments	4	(19)
Accumulated Deficit
Cash flows from operating activities:
Net loss	$ (76,781)	(69,950)
Supplemental disclosure of non-cash investing and financing activities:
Common stock issued in satisfaction of Symphony Icon payment obligation		$ 0