Cash and Marketable Securities

12 Months Ended

Dec. 31, 2019

Cash and Cash Equivalents [Abstract]

Cash and Marketable Securities

Cash, cash equivalents and restricted cash

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


	December 31, 2019		December 31, 2018		December 31, 2017
Cash and cash equivalents	$	79,449	$	77,123	$	218,375
Restricted cash included within prepaid expenses and other current assets	—		—		84
Restricted cash included within other non-current assets	1,500		1,500		451
Total cash, cash equivalents, and restricted cash	$	80,949	$	78,623	$	218,910

Marketable securities

All marketable securities were considered available-for-sale at December 31, 2019 and 2018. On a recurring basis, the Company records its marketable securities at fair value using Level 1 or Level 2 inputs as discussed in Note 2, "Fair Value Measurements". 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):


	December 31, 2019
	Amortized Cost		Unrealized Holding Gains		Unrealized Holding Losses		Aggregate Fair Value
Short-term marketable securities:
U.S. government treasuries	$	249,478	$	594	$	(2)	$	250,070
U.S. government agency securities	1,999		1		—		2,000
Corporate debt securities	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	13,865		6		(2)		13,869

Corporate debt securities	25,998		34		(15)		26,017
Total long-term marketable securities	39,863		40		(17)		39,886
Total	$	375,094	$	729	$	(30)	$	375,793


	December 31, 2018
	Amortized Cost		Unrealized Holding Gains		Unrealized Holding Losses		Aggregate Fair Value
Short-term marketable securities:
U.S. government treasuries	$	220,081	$	29	$	(356)	$	219,754
U.S. government agency securities	73,373		—		(222)		73,151
Corporate debt securities	71,940		1		(266)		71,675
Commercial paper	22,594		—		—		22,594
Total short-term marketable securities	387,988		30		(844)		387,174
Long-term marketable securities:
U.S. government treasuries	116,878		329		(76)		117,131
U.S. government agency securities	1,975		2		—		1,977
Corporate debt securities	28,864		8		(99)		28,773
Total long-term marketable securities	147,717		339		(175)		147,881
Total	$	535,705	$	369	$	(1,019)	$	535,055

As of December 31, 2019 and 2018, some of the Company’s marketable securities were in an unrealized loss position. The Company determined that it had the ability and intent to hold all marketable securities that have been in a continuous loss position until maturity or recovery, thus there was no recognition of any other-than-temporary impairment as of December 31, 2019 or 2018. All marketable securities with unrealized losses as of each balance sheet date have been in a loss position for less than twelve months or the loss is not material.

The Company recorded unrealized gains on marketable securities as other comprehensive income in the year ended December 31, 2019. As a result, the Company recorded a tax benefit of $0.4 million for the year ended December 31, 2019 on the Consolidated Statements of Operations and Comprehensive Loss and a corresponding tax charge in other comprehensive income. There were no unrealized gains in other comprehensive income during in the years ended 2018, or 2017, and as such there was no tax benefit recorded for the years ended December 31, 2018 and 2017 on the Consolidated Statements of Operations and Comprehensive Loss.

All of the Company’s marketable securities have an effective maturity of less than two years.