RESTATEMENT AND REVISION OF PRIOR PERIOD FINANCIAL STATEMENTS Condensed Consolidated Statements of Cash Flows (Details) - USD ($) $ in Thousands	3 Months Ended					6 Months Ended	9 Months Ended	12 Months Ended	36 Months Ended
	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Dec. 31, 2018	Mar. 31, 2019	Jun. 30, 2019	Jun. 30, 2019
Net Cash Provided by (Used in) Operating Activities [Abstract]
Net loss	$ (11,508)	$ (9,850)	$ (4,306)	$ (10,438)	$ (5,288)	$ (15,726)	$ (20,032)	$ (29,882)	$ (48,600)
Adjustments to Reconcile Net Income (Loss) to Cash Provided by (Used in) Operating Activities [Abstract]
Non-cash stock based compensation	290				415	972	1,393	1,750
(Gain) loss on disposal of property and equipment	(15)				7	(29)	(39)	672
Non-cash interest and amortization of debt discount	338				22	45	286	301
Bad debt expense	(110)				509	1,308	1,537	2,534
Provision for inventory reserve	574				212	1,211	2,699	3,172
Depreciation and amortization	1,656				1,975	3,972	5,899	7,504
Non-cash lease expense	491						14
Deferred income taxes	5				4	9		(7)
Accounts receivable	3,286				(3,663)	4,332	(6,288)	(8,706)
Finance receivables, net	(454)				(409)	(109)	(182)	(669)
Inventory, net	1,232				1,707	284	(5,349)	(5,607)
Prepaid expenses and other assets	(412)				(220)	(1,588)	(1,545)	(395)
Accounts payable and accrued expenses	5,290				(8,665)	(11,095)	(3,836)	1,039
Operating lease liabilities	(399)
Deferred revenue	(33)				(210)	(201)	(316)	(132)
Income taxes payable	(2)				11	25	42	254
Net cash provided by (used in) operating activities	229				(13,593)	(16,590)	(25,717)	(28,172)
Net Cash Provided by (Used in) Investing Activities [Abstract]
Purchase of property and equipment, including rentals	(420)				(1,222)	(2,324)	(3,156)	(4,875)
Proceeds from sale of property and equipment, including rentals	30				30	82	103	116
Net cash used in investing activities	(390)				(1,192)	(2,242)	(3,053)	(4,759)
Net Cash Provided by (Used in) Financing Activities [Abstract]
Proceeds from exercise of common stock options	0				42	42	42	42
Cash used for repurchase of common stock awards								(120)
Cash used in retirement of common stock								(81)
Payment of debt issuance costs						(53)	(135)	(156)
Repayment of capital lease obligations and long-term debt	(1,763)				(959)	(1,928)	(22,313)	(23,254)
Net cash used in financing activities	(1,763)				(917)	(1,939)	(22,406)	(23,569)
Net (decrease) increase in cash and cash equivalents	(1,924)				(15,702)	(20,771)	(51,176)	(56,500)
Cash and cash equivalents at beginning of year	27,464	32,788	63,193	68,262	83,964	83,964	83,964	83,964
Cash and cash equivalents at end of period	25,540	27,464	32,788	63,193	68,262	63,193	32,788	27,464	27,464
As Previously Reported
Net Cash Provided by (Used in) Operating Activities [Abstract]
Net loss	(12,897)	(10,541)	(4,510)	(10,657)	(6,320)	(16,977)	(21,487)	(32,028)
Adjustments to Reconcile Net Income (Loss) to Cash Provided by (Used in) Operating Activities [Abstract]
Non-cash stock based compensation	290				415	972	1,393	1,750
(Gain) loss on disposal of property and equipment	(15)				7	(29)	(39)	672
Non-cash interest and amortization of debt discount	338				22	45	286	301
Bad debt expense	(110)				509	1,308	1,537	2,534
Provision for inventory reserve	574				212	1,211	2,699	3,172
Depreciation and amortization	1,213				2,147	4,257	6,300	8,009
Non-cash lease expense	491						14
Deferred income taxes	5				4	9		(7)
Accounts receivable	4,677				(3,678)	4,312	(6,283)	(8,488)
Finance receivables, net	(384)				(63)	348	368	(8)
Inventory, net	992				1,707	284	(5,349)	(5,242)
Prepaid expenses and other assets	(412)				(220)	(1,588)	(1,545)	(395)
Accounts payable and accrued expenses	4,459				(8,665)	(11,095)	(3,866)	873
Operating lease liabilities	(399)
Deferred revenue	1,409				(210)	(201)	(316)	(98)
Income taxes payable	(2)				11	25	42	254
Net cash provided by (used in) operating activities	229				(14,122)	(17,119)	(26,246)	(28,701)
Net Cash Provided by (Used in) Investing Activities [Abstract]
Purchase of property and equipment, including rentals	(420)				(693)	(1,795)	(2,627)	(4,346)
Proceeds from sale of property and equipment, including rentals	30				30	82	103	116
Net cash used in investing activities	(390)				(663)	(1,713)	(2,524)	(4,230)
Net Cash Provided by (Used in) Financing Activities [Abstract]
Proceeds from exercise of common stock options					42	42	42	42
Cash used for repurchase of common stock awards								(120)
Cash used in retirement of common stock								(81)
Payment of debt issuance costs						(53)	(135)	(156)
Repayment of capital lease obligations and long-term debt	(1,763)				(959)	(1,928)	(22,313)	(23,254)
Net cash used in financing activities	(1,763)				(917)	(1,939)	(22,406)	(23,569)
Net (decrease) increase in cash and cash equivalents	(1,924)				(15,702)	(20,771)	(51,176)	(56,500)
Cash and cash equivalents at beginning of year	27,464	32,788	63,193	68,262	83,964	83,964	83,964	83,964
Cash and cash equivalents at end of period	25,540	27,464	32,788	63,193	68,262	63,193	32,788	27,464	27,464
Adjustments
Net Cash Provided by (Used in) Operating Activities [Abstract]
Net loss	1,389	691	204	219	1,032	1,251	1,455	2,146
Adjustments to Reconcile Net Income (Loss) to Cash Provided by (Used in) Operating Activities [Abstract]
Non-cash stock based compensation	0				0	0	0	0
(Gain) loss on disposal of property and equipment	0				0	0	0	0
Non-cash interest and amortization of debt discount	0				0	0	0	0
Bad debt expense	0				0	0	0	0
Provision for inventory reserve	0				0	0	0	0
Depreciation and amortization	443				(172)	(285)	(401)	(505)
Non-cash lease expense	0						0
Deferred income taxes	0				0	0		0
Accounts receivable	(1,391)				15	20	(5)	(218)
Finance receivables, net	(70)				(346)	(457)	(550)	(661)
Inventory, net	240				0	0	0	(365)
Prepaid expenses and other assets	0				0	0	0	0
Accounts payable and accrued expenses	831				0	0	30	166
Operating lease liabilities	0
Deferred revenue	(1,442)				0	0	0	(34)
Income taxes payable	0				0	0	0	0
Net cash provided by (used in) operating activities	0				529	529	529	529
Net Cash Provided by (Used in) Investing Activities [Abstract]
Purchase of property and equipment, including rentals	0				(529)	(529)	(529)	(529)
Proceeds from sale of property and equipment, including rentals	0				0	0	0	0
Net cash used in investing activities	0				(529)	(529)	(529)	(529)
Net Cash Provided by (Used in) Financing Activities [Abstract]
Proceeds from exercise of common stock options					0	0	0	0
Cash used for repurchase of common stock awards								0
Cash used in retirement of common stock								0
Payment of debt issuance costs						0	0	0
Repayment of capital lease obligations and long-term debt	0				0	0	0	0
Net cash used in financing activities	0				0	0	0	0
Net (decrease) increase in cash and cash equivalents	0				0	0	0	0
Cash and cash equivalents at beginning of year	0	0	0	0	0	0	0	0
Cash and cash equivalents at end of period	$ 0	$ 0	$ 0	$ 0	$ 0	$ 0	$ 0	$ 0	$ 0