XML 26 R38.htm IDEA: XBRL DOCUMENT v2.4.0.8
Investments in Debt Securities (Detail) (USD $)
Jun. 30, 2013
Dec. 31, 2012
Schedule of Available-for-sale Securities [Line Items]    
Amortized Cost $ 25,451,613 $ 20,745,938
Gross Unrealized Gain 12,865 15,479
Gross Unrealized Loss (5,357) (1,367)
Fair Value 25,459,121 20,760,050
Marketable securities
    
Schedule of Available-for-sale Securities [Line Items]    
Amortized Cost 20,805,600 10,835,995
Gross Unrealized Gain 11,962 9,207
Gross Unrealized Loss (3,729) (7)
Fair Value 20,813,833 10,845,195
Marketable securities | U.S. Government and agency securities
    
Schedule of Available-for-sale Securities [Line Items]    
Amortized Cost 1,539,779 2,000,897
Gross Unrealized Gain 111 353
Gross Unrealized Loss (37) (7)
Fair Value 1,539,853 2,001,243
Marketable securities | Corporate and other debt securities
    
Schedule of Available-for-sale Securities [Line Items]    
Amortized Cost 19,265,821 8,835,098
Gross Unrealized Gain 11,851 8,854
Gross Unrealized Loss (3,692)  
Fair Value 19,273,980 8,843,952
Long-term marketable securities
    
Schedule of Available-for-sale Securities [Line Items]    
Amortized Cost 4,646,013 9,909,943
Gross Unrealized Gain 903 6,272
Gross Unrealized Loss (1,628) (1,360)
Fair Value 4,645,288 9,914,855
Long-term marketable securities | U.S. Government and agency securities
    
Schedule of Available-for-sale Securities [Line Items]    
Amortized Cost 4,037,566 5,198,264
Gross Unrealized Gain 854 2,747
Gross Unrealized Loss (1,186)  
Fair Value 4,037,234 5,201,011
Long-term marketable securities | Corporate and other debt securities
    
Schedule of Available-for-sale Securities [Line Items]    
Amortized Cost 608,447 4,711,679
Gross Unrealized Gain 49 3,525
Gross Unrealized Loss (442) (1,360)
Fair Value $ 608,054 $ 4,713,844