Available for Sale Securities (Tables)

6 Months Ended

Jun. 30, 2015

Investments Debt And Equity Securities [Abstract]

Summary of Available for Sale Securities at Fair Value

Available for sale securities at June 30, 2015 and December 31, 2014 consist of the following:

			Gross		Gross
			Unrealized		Unrealized
	Amortized Cost		Gains		Losses			Fair Value
	(in thousands)
June 30, 2015
Cash and cash equivalents:
Cash and money market account	$	76,248	$	—	$	—		$	76,248
Total cash and cash equivalents	$	76,248	$	—	$	—		$	76,248
Available for sale securities:
Certificates of deposit	$	19,721	—		—			$	19,721
U.S. Government debt securities		38,546		10		(14	)		38,542
Corporate debt securities		18,301		2		(25	)		18,278
Total available for sale securities	$	76,568	$	12	$	(39	)	$	76,541
Total cash, cash equivalents, and available for sale    securities	$	152,816	$	12	$	(39	)	$	152,789

			Gross		Gross
			Unrealized		Unrealized
	Amortized Cost		Gains		Losses			Fair Value
	(in thousands)
December 31, 2014
Cash and cash equivalents:
Cash and money market account	$	32,780	$	—	$	—		$	32,780
Total cash and cash equivalents	$	32,780	$	—	$	—		$	32,780
Available for sale securities:
Certificates of deposit	$	13,429	—			—		$	13,429
U.S. Government debt securities		38,412		1		(28	)		38,385
Commercial paper		2,499		—		—			2,499
Corporate debt securities		21,854		3		(32	)		21,825
Total available for sale securities	$	76,194	$	4	$	(60	)	$	76,138
Total cash, cash equivalents, and available for sale securities	$	108,974	$	4	$	(60	)	$	108,918

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, 2015, by contractual maturity, is as follows:

Due in one year or less	$	37,785
Due after one year		38,756
Total available for sale securities	$	76,541