Fair Value Measurements (Details) - USD ($)
Dec. 31, 2015
Dec. 31, 2014
Fair Value Measurements    
Fair value assets, amount transferred between measurement levels $ 0 $ 0
Fair value liabilities, amount transferred between measurement levels 0 0
Recurring    
Fair Value Measurements    
Total 7,602,204 7,913,793
Recurring | U.S. corporations    
Fair Value Measurements    
Total 6,107,960 6,406,219
Recurring | International corporations    
Fair Value Measurements    
Total 1,494,244 1,507,574
Recurring | Significant Other Observable Inputs (Level 2)    
Fair Value Measurements    
Total 7,602,204 7,913,793
Recurring | Significant Other Observable Inputs (Level 2) | U.S. corporations    
Fair Value Measurements    
Total 6,107,960 6,406,219
Recurring | Significant Other Observable Inputs (Level 2) | International corporations    
Fair Value Measurements    
Total $ 1,494,244 $ 1,507,574