Investments

3 Months Ended

12 Months Ended

Mar. 31, 2021

Dec. 31, 2020

Investments, Debt and Equity Securities [Abstract]

Investments

4. Investments

The amortized cost, unrealized gains and losses, and fair value of our held-to-maturity investments at March 31, 2021 and December 31, 2020 are summarized as follows:

			Fair Value Measurements as of March 31, 2021
	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Fair Value
	(in thousands)
Held-to-maturity investments
Commercial paper	$	116,658	$	—	$	(24	)	$	116,634
State and municipal bonds		15,805		—		(21	)		15,784
Corporate bonds and notes		164,847		—		(644	)		164,203
Total held-to-maturity investments	$	297,310	$	—	$	(689	)	$	296,621

As of March 31, 2021, the Company has determined that the unrealized losses totaling $0.7 million is temporary and fully expects to recover the cost basis.

			Fair Value Measurements as of December 31, 2020
	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Fair Value
	(in thousands)
Held-to-maturity investments
Treasury securities	$	149,996	$	—	$	(1	)	$	149,995
Commercial paper		37,963		—		(15	)		37,948
Corporate bonds and notes		49,892		—		(63	)		49,829
Total held-to-maturity investments	$	237,851	$	—	$	(79	)	$	237,772

	March 31, 2021				December 31, 2020
	Amortized Cost		Fair Value		Amortized Cost		Fair Value
	(in thousands)				(in thousands)
Due in one year or less	$	144,829	$	144,788	$	201,881	$	201,864
Due after one year through five years		152,481		151,833		35,970		35,908
Total held-to-maturity securities	$	297,310	$	296,621	$	237,851	$	237,772

Note 6. Investments

The amortized cost, unrealized gains and losses, and fair value of our investments at December 31, 2020 are summarized as follows:

			Fair Value Measurements as of December 31, 2020
	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Fair Value
	(in thousands)
Held-to-maturity investments
Treasury securities	$	149,996	$	-	$	(1	)	$	149,995
Commercial paper		37,963		-		(15	)		37,948
Corporate bonds and notes		49,892		-		(63	)		49,829
Total held-to-maturity investments	$	237,851	$	-	$	(79	)	$	237,772

	December 31, 2020
	Amortized Cost		Fair Value
	(in thousands)
Due in one year or less	$	201,881	$	201,864
Due after one year through five years		35,970		35,908
Total held-to-maturity securities	$	237,851	$	237,772

The Company did not have any investments at December 31, 2019.