Income Taxes (Details 2) (USD $)	Dec. 31, 2011	Dec. 31, 2010
Deferred tax assets, current:
Deferred revenue	$ 3,151,000	$ 2,534,000
Other accrued liabilities and reserves	3,879,000	3,529,000
Stock compensation	9,074,000	10,056,000
Other	190,000	239,000
Total deferred tax assets, current	16,294,000	16,358,000
Non-current deferred tax assets:
Depreciation and amortization	(4,293,000)	(4,576,000)
Net operating losses, capital losses and credit carryforwards	31,324,000	35,010,000
Other	4,612,000	3,977,000
Valuation allowance	(892,000)	(820,000)
Total deferred tax assets, non-current	30,751,000	33,591,000
Deferred tax assets	47,045,000	49,949,000
Deferred tax liabilities	(2,930,000)	(534,000)
Net deferred tax assets	44,115,000	49,415,000
Valuation allowance against deferred tax assets relating to capital losses and investment reserves	826,000
Valuation allowance against deferred tax assets relating to state net operating losses	66,000
Federal net operating loss carryforwards	37,600,000
Stock-based compensation deductions included in federal net operating loss carryforwards	$ 20,900,000