Consolidated Statements of Cash Flows (USD $)	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Cash flows from operating activities:
Net income	$ 11,757,460	$ 8,466,680	$ 4,315,995
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	4,525,247	4,002,391	3,320,352
Stock-based compensation expense	1,151,199	1,190,697	1,102,617
Deferred income taxes	(10,269)	1,989,708	1,953,946
Provision for doubtful accounts	135,353	331,528	302,723
Provision for inventory	1,310,953	1,427,862	699,057
Tax benefit from exercise of stock options	(452,471)	(274,190)	(65,434)
Non-cash restructuring and impairment charges	1,604,256
Changes in operating assets and liabilities:
Accounts receivable	(4,271,129)	(2,998,037)	(3,716,478)
Inventories	(2,370,318)	224,714	(1,220,359)
Prepaid expenses and other current assets	200,453	947,263	445,650
Long-term deposits and other	33,995	179,939	28,239
Accounts payable	(2,879,330)	(6,594,292)	5,784,731
Accrued expenses	1,420,131	1,042,845	(2,188,082)
Deferred revenue	(2,858,262)	(213,888)	(2,751,468)
Income taxes payable	1,268,442	450,482
Other long-term liabilities	(17,033)	(568)	(158,028)
Net cash provided by operating activities	10,548,677	10,173,134	7,853,461
Cash flows from investing activities:
Purchase of property and equipment, net	(1,504,707)	(1,400,348)	(2,784,977)
Reduction in purchase price of acquisition			105,300
Net cash used in investing activities	(1,504,707)	(1,400,348)	(2,679,677)
Cash flows from financing activities:
Principal payments on debt	(1,600,000)	(1,600,000)	(1,600,000)
Proceeds from exercise of stock options	388,675	160,470	197,246
Tax benefit from exercise of stock options	452,471	274,190	65,434
Net cash used in financing activities	(758,854)	(1,165,340)	(1,337,320)
Exchange rate impact on cash	5,139	(32,156)	(61,522)
Increase in cash and cash equivalents	8,290,255	7,575,290	3,774,942
Cash and cash equivalents at beginning of period	35,777,222	28,201,932	24,426,990
Cash and cash equivalents at end of period	44,067,477	35,777,222	28,201,932
Supplemental disclosure of cash flow information:
Cash paid for income taxes	6,496,000	2,651,212	360,000
Cash paid for interest	$ 184,881	$ 193,880	$ 222,919