CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Cash Flows From Operating Activities:
Net loss	$ (198,607)	$ (117,500)	$ (95,708)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	233	163	120
Amortization of deferred debt costs	6,921	4,566	411
Stock-based compensation expense	12,575	9,724	4,722
Value of common stock issued for patent license	0	67	0
Accretion of discount/premium on available for sale securities	0	(109)	130
Change in fair value of derivative instruments—warrants	(106)	394	(1,362)
Common stock issued for interest on Notes	2,445	0	0
Debt conversion expense	40,158	0	0
Changes in operating assets and liabilities:
Inventories	(5,640)	0	0
Security deposits	0	(180)	(69)
Accounts payable and accrued expenses	11,546	1,867	316
Prepaid expenses and other current assets	2,416	531	(124)
Accrued interest expense on senior convertible notes	(1,694)	(512)	2,500
Total Adjustments	68,854	16,511	6,644
Net Cash used in Operating Activities	(129,753)	(100,989)	(89,064)
Cash Flows From Investing Activities:
Net sales (purchases) of available-for-sale securities	50,097	(200)	0
Additions to property and equipment	(297)	(50)	(173)
Repayment on ContraVir loan receivable	0	0	455
Net Cash provided by (used in) Investing Activities	49,800	(250)	282
Cash Flows From Financing Activities:
Proceeds of sale of common stock	89,845	14,672	30,700
Proceeds of sale of common stock — ContraVir	0	0	3,224
Issuance of Senior Convertible Debentures	0	0	200,000
Fees and expenses — note conversions	(711)	0	0
Payment for debt financing costs	0	0	(12,747)
Fees and expenses — sale of common stock	0	(404)	(861)
Proceeds from exercise of warrants	11,331	1,012	0
Proceeds from exercise of stock options	222	1,142	36
Distribution associated with ContraVir Spinoff	0	0	(3,230)
Net Cash provided by Financing Activities	100,687	16,422	217,122
Net increase (decrease) in cash and cash equivalents	20,734	(84,817)	128,340
Cash and cash equivalents at beginning of period	61,653	146,470	18,130
Cash and cash equivalents at end of period	82,387	61,653	146,470
Supplementary disclosure of cash flow information:
Cash paid for interest on senior convertible notes	5,939	13,379	0
Cash paid for taxes	45	258	55
Supplementary disclosure of non-cash investing and financing activities:
Distribution of net assets of ContraVir		0	84
Conversion of senior convertible notes to Synergy Common Stock	$ 137,941	$ 40,989	$ 0