XML 21 R10.htm IDEA: XBRL DOCUMENT v3.8.0.1
Marketable Securities (Notes)
 9 Months Ended
Sep. 30, 2017
Marketable Securities [Abstract]  
Investments in Debt and Marketable Equity Securities (and Certain Trading Assets) Disclosure [Text Block]
Marketable Securities
Marketable securities as of September 30, 2017 and December 31, 2016 consisted of the following:
September 30, 2017
Amortized
Cost
 
Gross
Unrealized
Gains
 
Gross
Unrealized
Losses
 
Fair
Value
Money market mutual funds
$
5,545

 
$
—

 
$
—

 
$
5,545

United States treasuries
2,010

 
—

 
(1
)
 
2,009

Certificates of deposit
743

 
—

 
—

 
743

Total marketable securities designated as available-for-sale
$
8,298

 
$
—

 
$
(1
)
 
$
8,297

 
December 31, 2016
Amortized
Cost
 
Gross
Unrealized
Gains
 
Gross
Unrealized
Losses
 
Fair
Value
Money market mutual funds
$
21,848

 
$
—

 
$
—

 
$
21,848

Certificates of deposit
3,864

 
—

 
—

 
3,864

Total marketable securities designated as available-for-sale
$
25,712

 
$
—

 
$
—

 
$
25,712


The amortized costs and fair value of marketable securities as of September 30, 2017 and December 31, 2016 are shown below by effective maturity. Effective maturities may differ from contractual maturities because the issuers of the securities may have the right to prepay obligations without prepayment penalties.
September 30, 2017
Amortized
Cost
 
Fair
Value
Due in less than one year
$
2,753

 
$
2,752

December 31, 2016
Amortized
Cost
 
Fair
Value
Due in less than one year
$
3,864

 
$
3,864


Interest income from marketable securities was $25 and $26 during the three months ended September 30, 2017 and 2016,