Available-for-Sale Securities

6 Months Ended

Jun. 30, 2021

Investments, Debt and Equity Securities [Abstract]

Available-for-Sale Securities

4. Available-for-Sale Securities

Estimated fair values of available-for-sale securities are generally based on prices obtained from commercial pricing services. The following table is a summary of available-for-sale securities recorded in cash and cash equivalents, restricted cash, or marketable securities in our condensed consolidated balance sheets (in thousands):

	June 30,2021								December 31, 2020
	Amortized		Unrealized		Unrealized		Estimated Fair		Amortized		Unrealized		Unrealized		Estimated Fair
	Cost		Gains		(Losses)		Value		Cost		Gains		(Losses)		Value
Financial Assets:
Money market funds	$	358,206	$	—	$	—	$	358,206	$	486,174	$	—	$	—	$	486,174
Corporate debt securities		11,239		33		—		11,272		29,641		163		—		29,804
U.S. government agency securities		1,800		—		—		1,800		15,906		37		—		15,943
Certificates of deposits		—		—		—		—		241		2		—		243
U.S. government securities		5,003		10		—		5,013		20,036		100		—		20,136
Total	$	376,248	$	43	$	—	$	376,291	$	551,998	$	302	$	—	$	552,300

The following table summarizes the classification of the available-for-sale securities on our condensed consolidated balance sheets (in thousands):

	June 30, 2021		December 31, 2020
Cash and cash equivalents	$	358,206	$	486,174
Short-term marketable securities		18,085		66,126
Total	$	376,291	$	552,300

We do not intend to sell the investments that are in an unrealized loss position, and it is unlikely that we will be required to sell the investments before recovery of their amortized cost basis, which may be maturity.