Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
CASH FLOWS FROM OPERATING ACTIVITIES:
Net loss	$ (27,961)	$ (13,368)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	467	372
Stock-based compensation	769	556
Accretion on asset retirement obligation	9	9
Change in fair value of warrant liabilities	15,231
Loss on disposal of property and equipment	6	2
Inventory lower of cost or market adjustment		235
Amortization of debt discount and interest accrual	785	462
Changes in operating assets and liabilities:
Accounts receivable	928	830
Inventory	(2,134)	(4,261)
Deposits on purchased inventory	(1,951)	384
Deferred cost of revenue	(2,341)	4,887
Prepaid expenses and other assets	(1,675)	(43)
Accounts payable	560	1,957
Accrued expenses and other long-term liabilities	(138)	504
Customer deposits and deferred revenue	5,481	(3,016)
Net cash used in operating activities	(11,964)	(10,490)
CASH FLOWS FROM INVESTING ACTIVITIES:
Purchase of property and equipment	(319)	(4,456)
Net cash used in investing activities	(319)	(4,456)
CASH FLOWS FROM FINANCING ACTIVITIES:
Proceeds from common stock private placement, gross	26,100
Payment of offering costs related to common stock private placement	(210)
Proceeds from the exercise of stock options	2	8
Net cash provided by financing activities	47,386	8
NET INCREASE (DECREASE) IN CASH AND CASH EQUIVALENTS	35,103	(14,938)
CASH AND CASH EQUIVALENTS — BEGINNING OF PERIOD	14,198	20,667
CASH AND CASH EQUIVALENTS — END OF PERIOD	49,301	5,729
SUPPLEMENTAL DISCLOSURE OF CASH FLOW INFORMATION:
Cash paid for interest	951	621
SUPPLEMENTAL NON-CASH INVESTING AND FINANCING ACTIVITIES:
Purchase of property and equipment in accounts payable and accrued expenses	135	932
Transfer of property and equipment from inventory		$ 1,728
Offering cost in accounts payable and accrued expenses	394
At The Market Offering Program [Member]
CASH FLOWS FROM FINANCING ACTIVITIES:
Proceeds from at-the-market offering of common stock, gross	21,921
Payment of offering costs related to at-the-market offering of common stock	$ (427)