Quarterly report pursuant to Section 13 or 15(d)

Summary of Significant Accounting Policies (Textual) (Details)

v2.4.0.6
Summary of Significant Accounting Policies (Textual) (Details) (USD $)
In Thousands, unless otherwise specified
3 Months Ended 12 Months Ended 3 Months Ended
Mar. 31, 2013
Criteria
Sep. 30, 2012
Mar. 31, 2012
Sep. 30, 2011
Dec. 31, 2011
Dec. 31, 2012
Intellectual Property [Member]
Mar. 31, 2013
Total Revenues [Member]
Customer Concentration Risk [Member]
customer
Mar. 31, 2012
Total Revenues [Member]
Customer Concentration Risk [Member]
Schedule of Available-for-sale Securities [Line Items]                
Number of major customers             5  
Major customers, percentage of total revenues             94.00% 83.00%
Maturity date of highly liquid investments 3 months              
Marketable securities included in non-current asset 1 year              
Selling, general and administrative expenses $ 8,124 $ 753 $ 9,395          
Significant realized gains or losses from sales of marketable securities 0     0        
Percentage of undiscounted cash flows greater than carrying value of asset group           14.00%    
Number revenue recognition criteria 4              
Change in accounting estimate         $ 530