XML 29 R17.htm IDEA: XBRL DOCUMENT v3.8.0.1
Summary of Significant Accounting Policies (Tables)
3 Months Ended
Mar. 31, 2018
Summary of Significant Accounting Policies [Abstract]  
Cash and Available-for-Sale Securities Adjusted Cost, Gross Unrealized Gains, Gross Unrealized Losses and Fair Value by Significant Investment Category
The following tables show the adjusted cost, gross unrealized gains, gross unrealized losses and fair value of our securities by significant investment category as of March 31, 2018 and December 31, 2017.

  
March 31, 2018
 
  
Adjusted
Cost
  
Unrealized
Gains
  
Unrealized
Losses
  
Fair Value
  
Cash and
Cash
Equivalents
  
Investments
Available for
Sale
 
Cash
 
$
3,501
  
$
  
$
  
$
3,501
  
$
3,501
  
$
 
                         
Level 1:
                        
Mutual funds
  
1,177
   
   
   
1,177
   
1,177
   
 
U.S. government securities
  
80
   
   
   
80
   
   
80
 
U.S. agency securities
  
1,369
   
   
   
1,369
   
866
   
503
 
   
2,626
   
   
   
2,626
   
2,043
   
583
 
Total
 
$
6,127
  
$
  
$
  
$
6,127
  
$
5,544
  
$
583
 

  
December 31, 2017
 
  
Adjusted
Cost
  
Unrealized
Gains
  
Unrealized
Losses
  
Fair
Value
  
Cash and
Cash
Equivalents
  
Investments
Available
for Sale
 
Cash
 
$
1,972
  
$
  
$
  
$
1,972
  
$
1,972
  
$
 
                         
Level 1:
                        
Mutual funds
  
616
   
   
   
616
   
616
     
U.S. agency securities
  
2,001
   
   
(1
)
  
2,000
   
547
   
1,453
 
   
2,617
   
   
(1
)
  
2,616
   
1,163
   
1,453
 
Total
 
$
4,589
  
$
  
$
(1
)
 
$
4,588
  
$
3,135
  
$
1,453