Quarterly report pursuant to Section 13 or 15(d)

FAIR VALUE MEASUREMENTS (Tables)

v3.10.0.1
FAIR VALUE MEASUREMENTS (Tables)
 6 Months Ended
Jun. 30, 2018
Fair Value Disclosures [Abstract]  
Available-for-sale Securities [Table Text Block] Available-for-sale investments included in cash equivalents at the end of each period were as follows (in thousands):
 
June 30, 2018
 
December 31, 2017
 
Adjusted Cost
 
Gross Unrealized Losses
 
Fair Value
 
Adjusted Cost
 
Gross Unrealized Losses
 
Fair Value
Municipal bonds and notes
$
7,176

 
$
(1
)
 
$
7,175

 
$
13,320

 
$
(1
)
 
$
13,319

Corporate debt securities
49,900

 
(22
)
 
49,878

 
49,432

 
(24
)
 
49,408

Financial institution instruments
20,093

 
—

 
20,093

 
10,881

 
—

 
10,881

Total available-for-sale investments
$
77,169

 
$
(23
)
 
$
77,146

 
$
73,633

 
$
(25
)
 
$
73,608