Fair Value of Financial Instruments (Tables)

6 Months Ended

Jun. 30, 2020

Fair Value Disclosures [Abstract]

Fair Values of Financial Instruments Measured on a Recurring Basis

The fair values of the financial instruments we measure at fair value on a recurring basis are as follows (in thousands):

	June 30, 2020
	Level 1		Level 2		Level 3		Total
Cash equivalents:
Money market funds	$	357,054	$	—	$	—	$	357,054
Commercial paper	—		176,304		—		176,304
Corporate bonds	—		4,045		—		4,045
U.S. treasury securities	28,893		—		—		28,893
Marketable securities:
Corporate bonds	—		356,837		—		356,837
U.S. treasury securities	226,000		—		—		226,000
Commercial paper	—		109,889		—		109,889
Asset-backed securities	—		66,751		—		66,751
Certificates of deposit	—		79,993		—		79,993
Prepaid expenses and other current assets:
Certificates of deposit	—		3,210		—		3,210
Restricted cash:
Certificates of deposit	$	—	$	23,221	$	—	$	23,221

	December 31, 2019
	Level 1		Level 2		Level 3		Total
Cash equivalents:
Money market funds	$	214,413	$	—	$	—	$	214,413
Commercial paper	—		105,354		—		105,354
Corporate bonds	—		3,791		—		3,791
Certificates of deposit	—		2,914		—		2,914
Marketable securities:
Corporate bonds	—		450,433		—		450,433
U.S. treasury securities	201,640		—		—		201,640
Commercial paper	—		196,328		—		196,328
Asset-backed securities	—		114,599		—		114,599
Certificates of deposit	—		100,679		—		100,679
Prepaid expenses and other current assets:
Certificates of deposit	—		2,738		—		2,738
Restricted cash:
Certificates of deposit	$	—	$	25,339	$	—	$	25,339

Fair Value of Marketable Securities by Contractual Maturity

The fair value of our marketable securities by contractual maturity is as follows (in thousands):

	June 30, 2020
Due in one year or less	$	637,398
Due after one to five years	202,072
Total	$	839,470