Consolidated Statements of Cash flows (USD $)	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Cash flows from operating activities:
Net loss	$ (7,039,866)	$ (4,384,435)	$ (1,106)
Adjustments to reconcile net loss to net cash provided by operating activities:
Depreciation and amortization	8,096,543	7,286,915	3,634,412
Loss on impairment	1,353,857
Loss on write down / disposal of property and equipment, net	2,800,396	73,061
Loss on disposal of intangibles	54,356	47,947	66,829
Bond premium amortization	371,304
Provision for doubtful accounts	296,016	48,903	82,251
Provision for excess and obsolete inventory	4,610,197	1,278,284	821,983
Provision for warranty	309,779	843,268	92,278
Stock-based compensation expense	3,038,300	3,682,675	4,988,837
Litigation judgment	3,301,243
Deferred income taxes	(2,480,856)	(1,088,377)	(1,188,157)
Provision for unrecognized tax benefits	(299,441)	17,061	572,699
Tax benefit from stock-based compensation	(9,828)	(52,147)	(31,659)
Change in assets and liabilities:
Accounts receivable	1,463,031	1,768,134	1,326,309
Inventory	1,327,801	(4,007,939)	(2,440,616)
Prepaid expenses and other assets	(373,709)	(1,715,403)	976,156
Accounts payable and accrued liabilities	109,051	(3,246,517)	1,031,196
Deferred revenue	296,422	163,876	142,634
Customer deposits	41,169	16,219	43,240
Net cash provided by operating activities	17,265,765	731,525	10,117,286
Cash flows from investing activities:
Purchases of investments	(11,479,493)
Proceeds from call / maturity of investments	6,000,000		2,500,000
Purchases of property and equipment	(1,854,083)	(4,023,691)	(13,708,177)
Proceeds from disposal of fixed assets	149,400	30,972
Purchases of intangible assets	(413,466)	(478,983)	(471,698)
Net cash used in investing activities	(7,597,642)	(4,471,702)	(11,679,875)
Cash flows from financing activities:
Repurchase of common stock	(32,498,856)
Repurchase of stock options		(124,230)
Proceeds from options exercised	1,427,418	1,001,476	155,544
Excess tax benefit from stock-based compensation	9,828	52,147	31,659
Net cash (used in) provided by financing activities	(31,061,610)	929,393	187,203
Effect of exchange rate changes on cash and cash equivalents	9,979	(10,024)
Net decrease in cash and cash equivalents	(21,383,508)	(2,820,808)	(1,375,386)
Cash and cash equivalents, beginning of year	42,684,241	45,505,049	46,880,435
Cash and cash equivalents, end of year	$ 21,300,733	$ 42,684,241	$ 45,505,049