Income Taxes (Details 2) (USD $)	Dec. 31, 2012	Dec. 31, 2011
Deferred tax assets, current:
Deferred revenue	$ 3,509,000	$ 3,151,000
Other accrued liabilities and reserves	5,304,000	3,879,000
Stock compensation	10,206,000	9,074,000
Other	(85,000)	190,000
Total deferred tax assets, current	18,934,000	16,294,000
Non-current deferred tax assets:
Depreciation and amortization	(2,176,000)	(4,293,000)
Net operating losses, capital losses and credit carryforwards	22,585,000	31,324,000
Other	4,977,000	4,612,000
Valuation allowance	(862,000)	(892,000)
Total deferred tax assets, non-current	24,524,000	30,751,000
Deferred tax assets	43,458,000	47,045,000
Deferred tax liabilities	(2,141,000)	(2,930,000)
Net deferred tax assets	41,317,000	44,115,000
Valuation allowance against deferred tax assets relating to capital losses and investment reserves	832,000
Valuation allowance against deferred tax assets relating to state net operating losses	31,000
Federal net operating loss carryforwards	$ 11,900,000