Cash, Cash Equivalents, and Available for Sale Marketable Investments (Tables)

9 Months Ended

Sep. 30, 2016

Cash and Cash Equivalents [Abstract]

Cash, cash equivalents and investments, available for sale

Cash, cash equivalents, and marketable securities included the following at September 30, 2016 and December 31, 2015:

	Amortized		Unrealized		Unrealized		Fair
	Cost		Gains		Losses		Value
	(in thousands)
As of September 30, 2016
Money market funds included in cash and cash equivalents	$	63,008	$	—	$	—	$	63,008
Total money market funds included in cash and cash equivalents	$	63,008	$	—	$	—	$	63,008
Marketable securities:
U.S. Treasury notes		112,489		—		3		112,486
U.S. Government agency bonds		15,153		7		—		15,160
Total debt securities	$	127,642	$	7	$	3	$	127,646
Equity securities		1,220		1,196		—		2,416
Total marketable securities	$	128,862	$	1,203	$	3	$	130,062
Total money market funds and marketable securities	$	191,870	$	1,203	$	3	$	193,070
As of December 31, 2015
Money market funds included in cash and cash equivalents	$	29,601	$	—	$	—	$	29,601
Total money market funds included in cash and cash equivalents	$	29,601	$	—	$	—	$	29,601
Marketable securities:
U.S. Treasury notes		158,166		—		185		157,981
U.S. Government agency bonds		35,121		—		66		35,055
Total marketable securities	$	193,287	$	—	$	251	$	193,036
Total money market funds and marketable securities	$	222,888	$	—	$	251	$	222,637

Estimated fair value of the Company’s marketable securities balance

The estimated fair value of the Company’s debt securities balance at September 30, 2016, by contractual maturity, is as follows:

Due in one year or less $ 127,646