Note 2 - Investments

12 Months Ended

Dec. 31, 2017

Notes to Financial Statements

Investments and Restricted Cash Disclosure [Text Block]

Note

2.

Investments

Investments

Our current investments, which are classified as "available for sale" and consist of bonds having maturities of greater than

90

days and less than

365

days, had a fair value of

$33.8

million and

$29.1

million at

December 

31,

2017

and

2016,

respectively. During

2017,

we had purchases of such investments of

$55.0

million and maturities of

$50.0

million. Our current investments at

December 

31,

2017

and

2016

consisted of the following (in thousands):

	December 31, 2017							December 31, 2016
	Amortized cost		Unrealized loss			Fair market value		Amortized cost		Unrealized loss			Fair market value
Corporate bonds	$	33,778	$	(20	)	$	33,758	$	22,100	$	(46	)	$	22,054
Municipal bonds		—		—			—		3,727		(1	)		3,726
Agency bonds		—		—			—		3,339		(2	)		3,337
Total	$	33,778	$	(20	)	$	33,758	$	29,166	$	(49	)	$	29,117

At

December 

31,

2017

and

2016,

the fair value of our non-current investments was

$7.6

million and

$5.0

million, respectively.  Our non-current investments consist of marketable equity securities which are carried at fair value, and are primarily classified as “available-for-sale.” The cost basis of our non-current investments was approximately

$5.7

million and

$4.1

million at

December 

31,

2017

and

2016,

respectively. In

2017

and

2016,

we acquired marketable equity securities having a cost basis of

$1.6

million and

$0.9

million, respectively. In

2016,

we recognized an impairment charge against current earnings of

$1.0

million, as we determined the impairment to be other-than-temporary.