Cash, Cash Equivalents and Short-Term Investments (Tables)

9 Months Ended

Sep. 30, 2020

Cash and Cash Equivalents [Abstract]

Schedule of Cash, Cash Equivalents and Short-Term Investments

The amortized cost, unrealized gains and losses and estimated fair value of the Company's cash, cash equivalents and short-term investments as of September 30, 2020 and December 31, 2019 consisted of the following:

	As of September 30, 2020
	Amortized Cost		Unrealized Gain		Unrealized Loss		Estimated Fair Value
Cash	$	71.6	$	—	$	—	$	71.6
Cash equivalents
Money market funds	371.2		—		—		371.2
Commercial paper	6.0		—		—		6.0
Corporate notes and obligations	2.9		—		—		2.9
Certificates of deposit	1.0		—		—		1.0
Total cash and cash equivalents	$	452.7	$	—	$	—	$	452.7
Short-term investments
Corporate notes and obligations	389.3		3.0		(0.1)		392.2
U.S. Treasury securities	205.3		1.3		—		206.6
Asset backed securities	84.0		0.7		—		84.7
U.S. agency obligations	37.0		0.1		—		37.1
Commercial paper	24.5		—		—		24.5
Certificates of deposit	16.5		—		—		16.5
Foreign government obligations	9.3		—		—		9.3
Municipal securities	2.9		—		—		2.9
Total short-term investments	768.8		5.1		(0.1)		773.8
Total	$	1,221.5	$	5.1	$	(0.1)	$	1,226.5

	As of December 31, 2019
	Amortized cost		Unrealized gain		Unrealized loss		Estimated fair value
Cash	$	105.0	$	—	$	—	$	105.0
Cash equivalents:
Money market funds	444.3		—		—		444.3
Commercial paper	2.0		—		—		2.0
Total cash and cash equivalents	$	551.3	$	—	$	—	$	551.3
Short-term investments							—
Corporate notes and obligations	285.5		1.2		(0.1)		286.6
U.S. Treasury securities	171.0		0.3		—		171.3
Asset backed securities	53.8		—		—		53.8
Certificates of deposit	38.2		—		—		38.2
U.S. agency obligations	27.2		—		—		27.2
Commercial paper	24.2		—		—		24.2
Supranational securities	4.0		—		—		4.0
Municipal securities	2.4		—		—		2.4
Total short-term investments	606.3		1.5		(0.1)		607.7
Total	$	1,157.6	$	1.5	$	(0.1)	$	1,159.0

Contractual Maturities of Short Term Investments

The following table presents the contractual maturities of the Company’s short-term investments as of September 30, 2020:

	As of September 30, 2020
	Amortized cost		Estimated fair value
Due within one year	348.3		349.2
Due between one to three years	347.3		350.9
Due after three years	73.2		73.7
Total	$	768.8	$	773.8