XML 19 R38.htm IDEA: XBRL DOCUMENT v2.4.0.8
Investments in Debt Securities (Detail) (USD $)
Sep. 30, 2013
Dec. 31, 2012
Schedule of Available-for-sale Securities [Line Items]    
Amortized Cost $ 24,851,145 $ 20,745,938
Gross Unrealized Gain 12,726 15,479
Gross Unrealized Loss (2,931) (1,367)
Fair Value 24,860,940 20,760,050
Marketable securities
    
Schedule of Available-for-sale Securities [Line Items]    
Amortized Cost 20,739,066 10,835,995
Gross Unrealized Gain 10,290 9,207
Gross Unrealized Loss (2,866) (7)
Fair Value 20,746,490 10,845,195
Marketable securities | U.S. Government and agency securities
    
Schedule of Available-for-sale Securities [Line Items]    
Amortized Cost 1,567,499 2,000,897
Gross Unrealized Gain 313 353
Gross Unrealized Loss (335) (7)
Fair Value 1,567,477 2,001,243
Marketable securities | Corporate and other debt securities
    
Schedule of Available-for-sale Securities [Line Items]    
Amortized Cost 19,171,567 8,835,098
Gross Unrealized Gain 9,977 8,854
Gross Unrealized Loss (2,531)  
Fair Value 19,179,013 8,843,952
Long-term marketable securities
    
Schedule of Available-for-sale Securities [Line Items]    
Amortized Cost 4,112,079 9,909,943
Gross Unrealized Gain 2,436 6,272
Gross Unrealized Loss (65) (1,360)
Fair Value 4,114,450 9,914,855
Long-term marketable securities | U.S. Government and agency securities
    
Schedule of Available-for-sale Securities [Line Items]    
Amortized Cost 4,112,079 5,198,264
Gross Unrealized Gain 2,436 2,747
Gross Unrealized Loss (65)  
Fair Value 4,114,450 5,201,011
Long-term marketable securities | Corporate and other debt securities
    
Schedule of Available-for-sale Securities [Line Items]    
Amortized Cost   4,711,679
Gross Unrealized Gain   3,525
Gross Unrealized Loss   (1,360)
Fair Value   $ 4,713,844