Consolidated Statements of Cash Flows - USD ($)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Cash flows from operating activities:
Net loss	$ (64,028,000)	$ (40,166,000)	$ (41,230,000)
Adjustments to reconcile net loss to net cash used in operating activities:
Goodwill impairment			14,278,000
Depreciation and amortization	3,034,000	1,177,000	318,000
Provision for doubtful accounts	493,000	437,000	233,000
Provision for warranties	294,000	71,000	385,000
Provision for inventory	3,125,000	1,323,000	469,000
Amortization of acquired inventory step-up	999,000	61,000
Change in fair value of warrants	95,000	39,000	(360,000)
Change in fair value of deferred and contingent consideration	1,025,000	37,000
Non-cash portion of debt extinguishment loss	17,000
Amortization of debt discount and issuance costs	140,000
Non-cash interest expense	1,000	3,000	1,386,000
Stock-based compensation expense	6,766,000	3,236,000	2,382,000
Loss on disposal of property and equipment	25,000	124,000
Deferred income taxes	(21,000)	61,000	0
Changes in assets and liabilities, net of effects from acquisitions:
Accounts receivable	(1,890,000)	927,000	715,000
Inventories	527,000	2,390,000	(898,000)
Prepaid expenses, other current assets and other assets	674,000	(529,000)	147,000
Insurance recovery receivable	9,336,000	(9,375,000)
Accounts payable	1,290,000	(564,000)	1,546,000
Accrued and other liabilities	3,218,000	(1,422,000)	1,571,000
Legal settlement payable	(9,900,000)	10,900,000
Customer deposits	(1,136,000)	(3,160,000)	874,000
Net cash used in operating activities	(45,916,000)	(34,430,000)	(18,184,000)
Cash flows from investing activities:
Purchase of property and equipment	(1,864,000)	(1,126,000)	(1,128,000)
Business acquisitions, net of cash acquired	(18,455,000)	(11,709,000)
Net cash used in investing activities	(20,319,000)	(12,835,000)	(1,128,000)
Cash flows from financing activities:
Proceeds from exercise of stock options	1,346,000	923,000	119,000
Proceeds from issuance of common stock under ESPP	647,000	753,000	564,000
Tax payments related to shares withheld for vested restricted stock units (RSUs)	(725,000)
Proceeds from issuance of common stock, net of underwriters discount			62,040,000
Deferred equity issuance costs, IPO			(71,000)
Deferred equity issuance costs, follow-on offering			(643,000)
Repayment of long-term debt			(26,625,000)
Gross borrowings under the Term Loan	25,000,000
Gross borrowings under the Revolving Line of Credit	5,000,000
Repayment of the Revolving Line of Credit	(5,000,000)
Deferred financing costs	(657,000)
Net cash provided by financing activities	25,611,000	1,676,000	35,384,000
Net decrease in cash and cash equivalents	(40,624,000)	(45,589,000)	16,072,000
Cash and cash equivalents at:
Beginning of period	67,212,000	112,801,000	96,729,000
End of period	26,588,000	67,212,000	112,801,000
Supplemental disclosure of cash flow information:
Interest paid	870,000	96,000	1,884,000
Supplemental disclosure of non-cash investing and financing activities:
Property and equipment in accounts payable and accrued liabilities	1,088,000	939,000	$ 22,000
Acquisition of business, deferred and contingent consideration obligations at fair value	10,912,000	$ 1,600,000
Forgiveness of SVB Loan commitment fee	750,000
Accrued deferred financing costs	$ 6,000