Condensed Consolidated Statements of Cash Flows (Unaudited) (USD $)	9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012
Cash flows from operating activities:
Net income	$ 13,920,152	$ 7,294,237
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	3,579,474	3,364,432
Stock-based compensation expense	1,156,929	914,003
Deferred income taxes	2,022,965	(1,012,571)
Provision for doubtful accounts	24,098	135,353
Provision for inventory	165,803	790,379
Gain on sale of assets	(442,341)
Tax benefit from exercise of stock options	(764,181)	(456,796)
Changes in operating assets and liabilities:
Accounts receivable	4,667,839	716,874
Inventories	(3,430,655)	(2,433,367)
Prepaid expenses, other current and long-term assets	531,449	429,718
Long-term deposits and other	25,497	25,496
Accounts payable	124,679	(2,399,999)
Accrued expenses	(642,430)	(873,153)
Deferred revenue	(2,150,000)	(2,150,000)
Income taxes payable	(1,256,367)	1,398,008
Other long-term liabilities	(373,712)	(6,318)
Net cash provided by operating activities	17,159,199	5,736,296
Cash flows from investing activities:
Proceeds from sale of assets	530,865
Purchase of property and equipment	(235,803)	(1,292,487)
Net cash provided by (used in) investing activities	295,062	(1,292,487)
Cash flows from financing activities:
Principal payments on debt	(1,200,000)	(1,200,000)
Proceeds from exercise of stock options	2,932,649	331,639
Tax benefit from exercise of stock options	764,181	456,796
Net cash provided by (used in) financing activities	2,496,830	(411,565)
Exchange rate impact on cash	36,870	46,390
Increase in cash and cash equivalents	19,987,961	4,078,634
Cash and cash equivalents at beginning of period	44,067,477	35,777,222
Cash and cash equivalents at end of period	$ 64,055,438	$ 39,855,856