Cash Equivalents & Marketable Securities (Tables)

12 Months Ended

Dec. 31, 2017

Cash Equivalents & Marketable Securities

Schedule of cash equivalents and marketable securities

Cash equivalents and marketable securities consisted of the following at December 31, 2017 (in thousands):

			Gross		Gross
	Amortized		Unrealized		Unrealized		Fair
December 31, 2017	Cost		Gains		Losses		Value
Cash equivalents:
Money market funds	$	134,635	$	—	$	—	$	134,635
U.S. Treasuries		11,995		—		—		11,995
Marketable securities:
U.S. Treasuries		123,606		—		(47)		123,559
Government agency securities		58,979		—		(29)		58,950
Total cash equivalents and marketable securities	$	329,215	$	—	$	(76)	$	329,139

Cash equivalents and marketable securities consisted of the following at December 31, 2016 (in thousands):

			Gross		Gross
	Amortized		Unrealized		Unrealized		Fair
December 31, 2016	Cost		Gains		Losses		Value
Cash equivalents:
Money market funds	$	185,323	$	—	$	—	$	185,323
Total cash equivalents and marketable securities	$	185,323	$	—	$	—	$	185,323