Short-Term Marketable Securities
 12 Months Ended
Dec. 31, 2016
Investments Debt And Equity Securities [Abstract]  
Short-Term Marketable Securities

2. Short-Term Marketable Securities

The following is a summary of short-term marketable securities classified as available-for-sale (in thousands):

 

December 31, 2016

 

Amortized

Cost

 

 

Unrealized

Gain

 

 

Unrealized

Loss

 

 

Market

Value

 

U.S. treasuries

 

$

23,295

 

 

$

—

 

 

$

18

 

 

$

23,277

 

Certificates of deposit

 

 

7,275

 

 

 

—

 

 

 

—

 

 

 

7,275

 

 

 

$

30,570

 

 

$

—

 

 

$

18

 

 

$

30,552

 

 

December 31, 2015

 

Amortized

Cost

 

 

Unrealized

Gain

 

 

Unrealized

Loss

 

 

Market

Value

 

U.S. treasuries

 

$

7,027

 

 

$

—

 

 

$

8

 

 

$

7,019

 

Corporate bonds

 

 

1,000

 

 

 

—

 

 

 

—

 

 

 

1,000

 

Certificates of deposit

 

 

15,239

 

 

 

—

 

 

 

—

 

 

 

15,239

 

 

 

$

23,266

 

 

$

—

 

 

$

8

 

 

$

23,258

 

 

At December 31, 2016, none of these securities were scheduled to mature outside of one year. There were no net realized gains (losses) on sales of available-for-sale securities for the years ended December 31, 2016, 2015 and 2014. None of these investments have been in a continuous unrealized loss position for more than 12 months as of December 31, 2016 and 2015.