Available for Sale Securities (Tables)

6 Months Ended

Jun. 30, 2016

Investments Debt And Equity Securities [Abstract]

Summary of Available for Sale Securities at Fair Value

Available for sale securities at June 30, 2016 and December 31, 2015 consist of the following:

			Gross		Gross
			Unrealized		Unrealized
	Amortized Cost		Gains		Losses			Fair Value
	(in thousands)
June 30, 2016
Cash and cash equivalents	$	46,177	$	—	$	—		$	46,177
Available for sale securities:
Certificates of deposit	$	19,063	—		—			$	19,063
U.S. Government debt securities		111,004		38		(5	)		111,037
Corporate debt securities		12,368		5		(1	)		12,372
Total available for sale securities	$	142,435	$	43	$	(6	)	$	142,472
Total cash, cash equivalents, and available for sale securities	$	188,612	$	43	$	(6	)	$	188,649

			Gross		Gross
			Unrealized		Unrealized
	Amortized Cost		Gains		Losses			Fair Value
	(in thousands)
December 31, 2015
Cash and cash equivalents	$	49,778	$	—	$	—		$	49,778
Available for sale securities:
Certificates of deposit	$	21,505	—			—		$	21,505
U.S. Government debt securities		46,461	—			(185	)		46,276
Corporate debt securities		20,944		1		(50	)		20,895
Total available for sale securities	$	88,910	$	1	$	(235	)	$	88,676
Total cash, cash equivalents, and available for sale securities	$	138,688	$	1	$	(235	)	$	138,454

Estimated Fair Value of Available for Sale Securities at Fair Value by Contractual Maturity

The estimated fair value of the Company’s available for sale securities balance at June 30, 2016, by contractual maturity, is as follows:

Due in one year or less	$	114,894
Due after one year		27,578
Total available for sale securities	$	142,472