Available-for-Sale Securities and Fair Value Measurements (Tables)

3 Months Ended

Mar. 31, 2020

Available For Sale Securities And Fair Value Measurements [Abstract]

Summary of the classification of available-for-sale securities in condensed consolidated balance sheets

The available-for-sale securities in our Condensed Consolidated Balance Sheets are as follows:

	March 31, 2020		December 31, 2019
	(in thousands)
Cash equivalents	$	67,227	$	18,461
Short-term marketable securities	222,838		244,693
Long-term marketable securities	41,690		39,352
Total marketable securities	$	331,755	$	302,506

Schedule of available-for-sale securities

The following table presents our available-for-sale securities grouped by asset type:

	Fair Value Hierarchy Level	March 31, 2020								December 31, 2019
		Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses		Estimated Fair Value		Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses		Estimated Fair Value
		(in thousands)
Corporate bonds	Level 2	$	115,877	$	22	$	(300)	$	115,599	$	109,780	$	136	$	(6)	$	109,910
Commercial paper	Level 2	34,191		—		—		34,191		41,237		—		—		41,237
Asset-backed securities	Level 2	39,803		9		(93)		39,719		57,195		63		(5)		57,253
Repurchase agreements	Level 2	—		—		—		—		18,000		—		—		18,000
U.S. treasury securities	Level 1	74,337		682		—		75,019		75,574		71		—		75,645
Money market funds	Level 1	67,227		—		—		67,227		461		—		—		461
Total Marketable securities		$	331,435	$	713	$	(393)	$	331,755	$	302,247	$	270	$	(11)	$	302,506