Fair Value of Financial Instruments (Tables)

3 Months Ended

Mar. 31, 2019

Fair Value Disclosures [Abstract]

Fair value 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):

	March 31, 2019
	Level 1		Level 2		Level 3		Total
Cash equivalents:
Commercial paper	$	—	$	76,897	$	—	$	76,897
Money market funds	546		—		—		546
Marketable securities:
Corporate bonds	—		214,819		—		214,819
Asset-backed securities	—		108,059		—		108,059
Certificates of deposit	—		64,418		—		64,418
Commercial paper	—		100,212		—		100,212
U.S. treasury securities	20,060		—		—		20,060
Prepaid expenses and other current assets:
Certificates of deposit	—		1,057		—		1,057
Restricted cash:
Certificates of deposit	—		25,724		—		25,724
Other liabilities:
Redeemable convertible preferred stock warrants	$	—	$	—	$	5,005	$	5,005

	December 31, 2018
	Level 1		Level 2		Level 3		Total
Cash equivalents:
Money market funds	$	785	$	—	$	—	$	785
Commercial paper	—		73,486		—		73,486
Marketable securities:
Corporate bonds	—		204,170		—		204,170
U.S. treasury securities	35,921		—		—		35,921
Asset-backed securities	—		106,658		—		106,658
Certificates of deposit	—		68,359		—		68,359
Commercial paper	—		90,196		—		90,196
Prepaid expenses and other current assets:
Certificates of deposit	—		1,057		—		1,057
Restricted cash:
Certificates of deposit	—		11,724		—		11,724
Other liabilities:
Redeemable convertible preferred stock warrants	$	—	$	—	$	4,934	$	4,934

Fair value of our marketable securities by contractual maturity

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

	March 31, 2019
Due in one year or less	$	319,271
Due after one to five years	188,297
Total	$	507,568