RESTATEMENT OF CONSOLIDATED FINANCIAL STATEMENTS - Condensed Consolidated Balance Sheet Impact of Adjustments (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Oct. 01, 2018	Sep. 30, 2018	Jul. 01, 2018	Jun. 30, 2018	Dec. 31, 2017
Cash and cash equivalents	$ 63,193				$ 83,964	$ 15,360
Accounts receivable	10,132				15,748	14,707
Finance receivables, net	5,591				4,603	3,296
Inventory, net	7,343				8,038	12,019
Prepaid expenses and other current assets	2,871			$ 1,180	929	1,610
Finance receivables due after one year, net	11,910				13,246	11,728
Other assets	1,903			1,974	720	458
Goodwill	64,149				64,149	64,403
Property and equipment, net	9,546				11,273	12,443
Accounts payable	17,570				30,468	23,908
Accrued expenses	21,150				19,291	16,623
Capital lease obligation and current obligations under long-term debt	33,235				34,639	5,488
Capital lease obligations and long-term debt, less current portion	632				1,127
Deferred revenue	1,437	$ 1,428	$ 1,428	$ 1,638	511	730
Common stock	$ 376,363				$ 375,436	310,150
Deferred gain from sale-leaseback transactions						0
Deferred gain from sale-leaseback transactions, less current portion						0
Restatement Adjustment
Cash and cash equivalents						(26)
Accounts receivable						(765)
Finance receivables, net						(2,221)
Inventory, net						804
Prepaid expenses and other current assets						(361)
Finance receivables due after one year, net						513
Other assets						(662)
Goodwill						(46)
Property and equipment, net						(179)
Accounts payable						133
Accrued expenses						9,825
Capital lease obligation and current obligations under long-term debt						367
Deferred revenue						135
Common stock						3,097
Deferred gain from sale-leaseback transactions						(198)
Deferred gain from sale-leaseback transactions, less current portion						(49)
Audit Committee Investigation-related Adjustments | Restatement Adjustment
Accounts receivable						(1,774)
Finance receivables, net						(1,269)
Inventory, net						2,166
Prepaid expenses and other current assets						25
Other assets						76
Property and equipment, net						(162)
Accounts payable						106
Accrued expenses						580
Acquisition and Financial Integration-related Adjustments | Restatement Adjustment
Cash and cash equivalents						(26)
Accounts receivable						1,133
Finance receivables, net						(1,324)
Inventory, net						(500)
Prepaid expenses and other current assets						(35)
Finance receivables due after one year, net						(191)
Other assets						(139)
Goodwill						4,121
Property and equipment, net						721
Accrued expenses						785
Deferred revenue						(153)
Common stock						3,469
Significant Account and Transaction Review and Other | Restatement Adjustment
Accounts receivable						(8)
Finance receivables, net						371
Inventory, net						(861)
Prepaid expenses and other current assets						(150)
Finance receivables due after one year, net						703
Other assets						(600)
Property and equipment, net						(737)
Accounts payable						27
Accrued expenses						9,087
Capital lease obligation and current obligations under long-term debt						367
Capital lease obligations and long-term debt, less current portion						697
Deferred revenue						(27)
Common stock						(372)
Deferred gain from sale-leaseback transactions						(198)
Deferred gain from sale-leaseback transactions, less current portion						$ (49)