Summary of Significant Accounting Policies - Additional Information (Detail) (USD $)	3 Months Ended		6 Months Ended					3 Months Ended	6 Months Ended
	Jun. 30, 2013 Customer	Jun. 30, 2012 Customer	Jun. 30, 2013 Segment Customer	Jun. 30, 2012 Customer	Dec. 31, 2012 Customer	Nov. 30, 2012 Patents	Nov. 21, 2012 Patents	Mar. 31, 2013 License Agreements [Member]	Jun. 30, 2013 Minimum [Member]	Jun. 30, 2013 Maximum [Member]
Organization And Summary Of Significant Accounting Policies [Line Items]
Marketable securities, maturities remaining			2 years
Marketable securities, amortized cost	$ 100,387,064		$ 100,387,064		$ 100,082,602
Marketable securities	100,357,728		100,357,728		100,160,889
Marketable securities, unrealized gains	29,692		29,692		82,787
Marketable securities, unrealized losses	59,028		59,028		4,500
Revenue, subscription period, Minimum			1 month
Revenue, subscription period, Maximum			5 years
Average subscription period			1 year
Accounts receivable, customers accounted description	10% of accounts receivable		10% of accounts receivable		10% or more of accounts receivable
Accounts receivable, number of customers accounted	1		1		0
Revenue, customers accounted description	10% or more of revenue	10% or more of revenue	10% or more of revenue	10% or more of revenue
Revenue, number of customers accounted	0	0	0	0
Reduction in research and development expenses	35,000
Intangible assets, estimated useful lives									1 year	7 years
Foreign currency losses	199,000	269,000		506,000
Foreign currency gains			454,000
Uncertain tax positions	272,000		272,000		251,000
Number of segment			1
General and administrative expense	$ 6,351,845	$ 4,799,987	$ 17,872,172	$ 9,705,251				$ 1,200,000
Number of patents involved in infringement lawsuit						3	3