Condensed 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	$ (23,368,283)	$ (35,375,621)	$ (3,092,705)
Adjustments to reconcile net loss to net cash from operating activities:
Depreciation and amortization	4,107,761	5,644,682	5,889,353
Share-based payment compensation	5,493,689	7,866,384	8,551,961
Non-cash professional services expenses	24,369	819,185	275,480
Realized loss (gain) on marketable securities	0	90,761	21,582
Impairment of cost method investments	41,780	0	57,068
Excess tax benefits from stock-based award activity	0	0	(125,792)
Provision for returns and doubtful accounts	120,992	1,211,838	3,163,697
Deferred income tax provision	(160,434)	16,075,130	(4,112,205)
Changes in operating assets and liabilities:
Accounts receivable	3,830,769	438,529	(3,111,342)
Prepaid expenses and other current assets	(333,732)	826,643	(169,138)
Inventory	(359,348)	(1,080,002)	(75,705)
Other assets	48,135	204,657	31,153
Accounts payable	1,446,111	(96,236)	839,210
Accrued expenses and other liabilities	8,670,790	324,726	507,140
Deferred revenue	3,576,167	1,320,820	156,734
Net cash provided by (used in) operating activities	3,138,766	(1,728,504)	8,806,491
Cash flows from investing activities:
Sales of marketable securities	22,098,206	34,148,774	29,499,217
Purchases of marketable securities	(24,101,138)	(27,586,592)	(35,066,943)
Purchases of property and equipment	(2,220,380)	(2,700,378)	(4,303,718)
Purchase of software licenses	0	0	(950,000)
Capitalized software development costs	(1,001,025)	(107,206)	(80,703)
Security deposits	(48,238)	9,081	(33,440)
Purchase of intangible assets	(127,890)	(129,306)	(83,973)
Net cash used in investing activities	(5,400,465)	3,634,373	(11,019,560)
Cash flows from financing activities:
Proceeds from exercise of stock options	920,106	409,889	35,520
Payments to acquire treasury stock	0	0	(3,988,011)
Excess tax benefits from stock-based award activity	0	0	125,792
Net cash provided by financing activities	920,106	409,889	(3,826,699)
Effect of exchange rate changes on cash and cash equivalents	(243,268)	(225,731)	(571,939)
Net (decrease) increase in cash and cash equivalents	(1,584,861)	2,090,027	(6,611,707)
Cash and cash equivalents, beginning of period	17,842,555	15,752,528	22,364,235
Cash and cash equivalents, end of period	16,257,694	17,842,555	15,752,528
Cash paid for income taxes	$ 1,221,294	$ 721,159	$ 130,125