Note

Investments

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

days and less than

365

days, had a fair value and cost basis of

$33.0

million and

$29.1

million at

September

30,

2017

and

December

31,

2016,

respectively. During the

first

nine

months of

2017,

we had purchases of such investments of

$35.3

million and maturities of

$31.2

million. Our current investments at

September

30,

2017

and

December

31,

2016

consisted of the following (in thousands):

	September 30, 2017							December 31, 2016
	Amortized cost		Unrealized loss			Fair value		Amortized cost		Unrealized loss			Fair value
Corporate bonds	$	32,987	$	(14	)	$	32,973	$	22,100	$	(46	)	$	22,054
Municipal bonds		—		—			—		3,727		(1	)		3,726
Agency bonds		—		—					3,339		(2	)		3,337
Total	$	32,987	$	(14	)	$	32,973	$	29,166	$	(49	)	$	29,117

September

30,

2017

and

December

31,

2016,

the fair value of our non-current investments was

$7.1

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

$4.0

million at

September

30,

2017

and

December

31,

2016,

respectively. In the

first

nine

months of

2017

and

2016,

we acquired marketable equity securities having a cost basis of

$1.6

million and

$0.9

million, respectively. During the

first

quarter of

2016,

we recognized an impairment charge against current earnings of

$1.0

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