Investments (Tables)

3 Months Ended

Mar. 31, 2021

Investments All Other Investments [Abstract]

Investments Measured at Fair Value on Recurring Basis

The following tables summarize, by major security type, our short-term investments that are measured at fair value on a recurring basis, in thousands:

		March 31, 2021
	Maturities (years)	Amortized Cost		Unrealized Gains		Unrealized Losses			Fair Value
Cash equivalents:
Money market funds	1 or less	$	105,195	$	—	$	—		$	105,195
Short-term investments:
Commercial paper	1 or less		169,353		—		—			169,353
Corporate debt securities	2 or less		163,162		12		(142	)		163,032
U.S. Treasury securities	2 or less		160,607		46		—			160,653
Total short-term investments			493,122		58		(142	)		493,038
Total		$	598,317	$	58	$	(142	)	$	598,233

		December 31, 2020
	Maturities (years)	Amortized Cost		Unrealized Gains		Unrealized Losses			Fair Value
Cash equivalents:
Money market funds	1 or less	$	311,239	$	—	$	—		$	311,239
Commercial paper	1 or less		5,998		—		—			5,998
Total cash equivalents			317,237		—		—			317,237
Short-term investments:
Commercial paper	1 or less		106,350		—		—			106,350
Corporate debt securities	2 or less		113,020		36		(36	)		113,020
U.S. Treasury securities	1 or less		88,409		50		(2	)		88,457
Total short-term investments			307,779		86		(38	)		307,827
Total		$	625,016	$	86	$	(38	)	$	625,064