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

6 Months Ended

Jun. 30, 2016

Cash and Cash Equivalents [Abstract]

Cash, cash equivalents and investments, available for sale

Cash, cash equivalents and available for sale investments included the following at June 30, 2016 and December 31, 2015:

	Amortized		Unrealized		Unrealized		Fair
	Cost		Gains		Losses		Value
	(in thousands)
As of June 30, 2016
Money market funds included in cash and cash equivalents	$	65,463	$	—	$	—	$	65,463
Total money market funds included in cash and cash equivalents	$	65,463	$	—	$	—	$	65,463
Marketable securities:
U.S. Treasury notes		109,964		55		—		110,019
U.S. Government agency bonds		26,937		5		—		26,942
Total marketable securities	$	136,901	$	60	$	—	$	136,961
Total money market funds and marketable securities	$	202,364	$	60	$	—	$	202,424
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 marketable securities balance at June 30, 2016, by contractual maturity, is as follows:

Due in one year or less $ 136,961