Investments (Tables)

6 Months Ended

Jun. 30, 2015

Investments

Schedule of marketable investments classified as held-to-maturity

Marketable investments classified as held-to-maturity consist of the following (in thousands):

As of June 30, 2015	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Fair Value
Government-sponsored enterprises	$	87,632	$	61	$	(30	)	$	87,663
Corporate notes and bonds	219,609		251		(10		)	219,850
Total	$	307,241	$	312	$	(40	)	$	307,513
Reported under the following captions on the consolidated balance sheet:
Current marketable investments	$	185,774
Noncurrent marketable investments	121,467
	$	307,241

As of December 31, 2014	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Fair Value
Government-sponsored enterprises	$	127,212	$	118	$	(39	)	$	127,291
Corporate notes and bonds	293,288		260		(108		)	293,440
Total	$	420,500	$	378	$	(147	)	$	420,731
Reported under the following captions on the consolidated balance sheet:
Current marketable investments	$	297,842
Noncurrent marketable investments	122,658
	$	420,500

Summary of gross unrealized losses and the length of time marketable investments have been in a continuous unrealized loss position

The following table summarizes gross unrealized losses and the length of time marketable investments have been in a continuous unrealized loss position (in thousands):

	As of June 30, 2015					As of December 31, 2014
	Fair Value		Gross Unrealized Loss			Fair Value		Gross Unrealized Loss
Government-sponsored enterprises:
Continuous unrealized loss position less than one year	$	25,288	$	(30	)	$	15,293	$	(39	)
Continuous unrealized loss position greater than one year	—		—			—		—
	25,288		(30		)	15,293		(39		)
Corporate notes and bonds:
Continuous unrealized loss position less than one year	14,493		(10		)	86,824		(97		)
Continuous unrealized loss position greater than one year	—		—			3,443		(11		)
	14,493		(10		)	90,267		(108		)
Total	$	39,781	$	(40	)	$	105,560	$	(147	)

Summary of the contractual maturities of held-to-maturity marketable investments

The following table summarizes the contractual maturities of held-to-maturity marketable investments (in thousands):

	June 30, 2015
	Amortized Cost		Fair Value
Due in less than one year	$	185,774	$	185,916
Due in one to two years	121,467		121,597
Due in three to five years	—		—
Due after five years	—		—
Total	$	307,241	$	307,513