Condensed Consolidated Statement Of Cash Flows - USD ($)	6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017
Operating Activities
Net loss	$ (30,651,000)	$ (40,288,000)
Adjustments to reconcile net loss to net cash used by operating activities:
Depreciation and amortization	7,700,000	7,312,000
Provision for losses on trade and installment receivables	716,000	500,000
Benefit for deferred income taxes	(128,000)	(759,000)
Provision for other deferred liabilities	(7,000)	400,000
Provision for equity compensation	2,943,000	4,646,000
Loss (gain) on disposals of property and equipment	21,000	(91,000)
Amortization of convertible debt discount	5,650,000	3,451,000
Amortization of debt fees	1,246,000	985,000
(Gain) Loss on convertible debt derivatives	124,000	(150,000)
Changes in operating assets and liabilities:
Trade receivables	(1,659,000)	(5,396,000)
Installment sales contracts, net	294,000	(186,000)
Inventories	(17,079,000)	(13,095,000)
Other current assets	(1,076,000)	1,262,000
Accounts payable	3,231,000	(2,376,000)
Accrued expenses	(18,289,000)	(5,851,000)
Other long-term liabilities	114,000	(1,132,000)
Net Cash Used by Operating Activities	(47,098,000)	(50,468,000)
Investing Activities
Purchases of property and equipment	(4,227,000)	(5,504,000)
Proceeds from sale of property and equipment	37,000	190,000
Change in other long-term assets	(298,000)	(218,000)
Other	11,000	(87,000)
Net Cash Used by Investing Activities	(4,477,000)	(5,619,000)
Financing Activities
Proceeds from revolving lines of credit and long-term borrowings	0	95,220,000
Payments on revolving lines of credit and long-term borrowings	(602,000)	(14,881,000)
Proceeds from exercise of stock options	2,618,000	1,429,000
Payment of financing costs	0	4,144,000
Payment of dividends	(808,000)	(793,000)
Issuance of warrants	0	14,100,000
Purchase of treasury stock	(2,404,000)	(1,221,000)
Net Cash (Used) Provided by Financing Activities	(1,196,000)	89,710,000
Effect of exchange rate changes on cash	(1,359,000)	2,225,000
Increase (decrease) in cash and cash equivalents	(54,130,000)	35,848,000
Cash and cash equivalents at beginning of year	176,528,000	124,234,000
Cash and cash equivalents at end of period	$ 122,398,000	$ 160,082,000