Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
CASH FLOWS FROM OPERATING ACTIVITIES
Net income (loss)	$ 4,172	$ 8,006	$ 2,640
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation	25,904	20,346	15,804
Amortization of intangible assets	9,817	9,925	5,928
Non-cash stock-based compensation	10,212	10,000	6,955
Non-cash operating lease expense	6,168	5,635	0
Amortization of convertible debt discount	4,358	0	0
Amortization of debt issuance costs	165	390	542
Loss on debt extinguishment	1,400	1,018	0
Loss on termination of cash flow hedge	3,506	0	0
Unrealized gain on investment in non-consolidated affiliate, net	(3,955)	0	0
Other non-cash items	1,460	472	404
Changes in assets and liabilities, net:
Accounts receivable, net	(12,601)	(17,301)	209
Inventories	(15,197)	(5,754)	734
Prepaid lease asset	(20,229)	0	0
Prepaid and other assets	(9,750)	(367)	(1,834)
Accounts payable, accrued and other liabilities	(3,970)	(9,001)	13,404
Net cash provided by operating activities	1,460	23,369	44,786
CASH FLOWS FROM INVESTING ACTIVITIES
Purchases of marketable securities	(73,101)	0	0
Proceeds from sales and maturities of marketable securities	5,356	0	0
Purchases of property and equipment	(29,096)	(20,029)	(14,310)
Business acquisition	(37,000)	0	(125,377)
Investment in non-consolidated affiliate	(25,600)	0	0
Acquisition working capital adjustment	0	399	0
Net cash used in investing activities	(159,441)	(19,630)	(139,687)
CASH FLOWS FROM FINANCING ACTIVITIES
Advances on revolving credit facility	0	0	15,000
Repayment of revolving credit facility	0	(5,000)	(35,400)
Redemption of preferred stock	0	0	(50,096)
Repayment of equipment financing obligations	(5,615)	(7,201)	(6,563)
Proceeds from term loan	0	100,000	30,000
Repayment of term loan	(97,540)	(99,250)	(4,500)
Cash flow hedge termination	(3,317)	0	0
Payments of debt issuance costs for term loan	0	(1,059)	(576)
Issuance of common stock, net	20,310	11,202	9,023
Proceeds from issuance of convertible debt, net of issuance costs	194,466	0	0
Proceeds from equity offering, net of issuance costs	127,293	160,774	135,071
Net cash provided by financing activities	235,597	159,466	91,959
Effects of foreign exchange rate changes on cash and cash equivalents	0	0	(68)
Net change in cash and cash equivalents	77,616	163,205	(3,010)
Cash and cash equivalents, beginning of year	173,016	9,811	12,821
Cash, cash equivalents and restricted cash, end of year	250,632	173,016	9,811
Cash and cash equivalents	228,713	173,016	9,811
Restricted cash	21,919	0	0
Supplemental disclosure of cash flow information:
Interest paid	2,926	4,775	6,511
Income taxes paid (refunded), net	246	319	(31)
Supplemental disclosure of non-cash investing and financing information:
Fair value of common stock issued to fund acquisition	0	0	13,243
Working capital adjustment related to acquisition	0	1,977	0
Equipment acquired under financing obligations	428	4,283	7,569
Property and equipment included in accounts payable	$ 2,007	$ 1,034	$ 660