Cash and Marketable Securities (Tables)

3 Months Ended

Mar. 31, 2020

Cash and Cash Equivalents [Abstract]

Schedule of Cash and Cash Equivalents

A reconciliation of cash, cash equivalents, and restricted cash reported within the Condensed Consolidated Balance Sheets to the amount reported within the Condensed Consolidated Statements of Cash Flows is shown in the table below (in thousands):

	March 31,		December 31,		March 31,		December 31,
	2020		2019		2019		2018
Cash and cash equivalents	$	207,537	$	79,449	$	39,661	$	77,123
Restricted cash included within other non-current assets	1,500		1,500		1,500		1,500
Total cash, cash equivalents, and restricted cash	$	209,037	$	80,949	$	41,161	$	78,623

Schedule of Restricted Cash and Cash Equivalents

A reconciliation of cash, cash equivalents, and restricted cash reported within the Condensed Consolidated Balance Sheets to the amount reported within the Condensed Consolidated Statements of Cash Flows is shown in the table below (in thousands):

	March 31,		December 31,		March 31,		December 31,
	2020		2019		2019		2018
Cash and cash equivalents	$	207,537	$	79,449	$	39,661	$	77,123
Restricted cash included within other non-current assets	1,500		1,500		1,500		1,500
Total cash, cash equivalents, and restricted cash	$	209,037	$	80,949	$	41,161	$	78,623

Summary of Available for Sale Securities

The amortized cost, gross unrealized holding gains or losses, and fair value of the Company’s marketable securities by major security type at each balance sheet date are summarized in the tables below (in thousands):

	March 31, 2020
	Amortized Cost		Unrealized Holding Gains		Unrealized Holding Losses		Aggregate Fair Value
Short-term marketable securities:
U.S. government treasuries	$	272,289	$	1,391	$	—	$	273,680
Corporate debt securities(1)	61,920		39		(193)		61,766
Commercial paper	44,267		—		—		44,267
Total short-term marketable securities	378,476		1,430		(193)		379,713
Long-term marketable securities:
U.S. government treasuries	2,525		40		—		2,565
Corporate debt securities(2)	7,153		—		(34)		7,119
Total long-term marketable securities	9,678		40		(34)		9,684
Total	$	388,154	$	1,470	$	(227)	$	389,397

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(1)Unrealized holding losses on 10 securities, with an aggregate fair value of $35.7 million.

(2)Unrealized holding losses on 1 security, with an aggregate fair value of $7.1 million.

	December 31, 2019
	Amortized Cost		Unrealized Holding Gains		Unrealized Holding Losses		Aggregate Fair Value
Short-term marketable securities:
U.S. government treasuries(1)	$	249,478	$	594	$	(2)	$	250,070
U.S. government agency securities	1,999		1		—		2,000
Corporate debt securities(2)	53,396		94		(11)		53,479
Commercial paper	30,358		—		—		30,358
Total short-term marketable securities	335,231		689		(13)		335,907
Long-term marketable securities:
U.S. government treasuries(3)	13,865		6		(2)		13,869
Corporate debt securities(4)	25,998		34		(15)		26,017
Total long-term marketable securities	39,863		40		(17)		39,886
Total	$	375,094	$	729	$	(30)	$	375,793

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(1)Unrealized holding losses on 2 securities, with an aggregate fair value of $9.3 million.

(2)Unrealized holding losses on 4 securities, with an aggregate fair value of $25.9 million.

(3)Unrealized holding losses on 1 security, with an aggregate fair value of $10.1 million.

(4)Unrealized holding losses on 3 securities, with an aggregate fair value of $17.2 million.