Investments

6 Months Ended

Jun. 30, 2021

Investments

Investments

18. Investments

The amortized cost, gross unrealized gains and losses, fair value of those investments classified as available-for-sale, and allowance for credit losses at June 30, 2021 are summarized as follows (in thousands):

	Amortized		Gross		Gross		Fair		Allowance for
	Cost		Unrealized Gains		Unrealized Losses		Value		Credit Losses
Corporate bonds	$	707,022	$	51	$	(1,989)	$	705,084		—
Commercial paper		329,471		253		(2)		329,722		—
Certificates of deposit		27,460		—		(6)		27,454		—
U.S. Treasuries		170,672		—		(195)		170,477		—
Municipal debt		9,993		—		(9)		9,984		—
Total	$	1,244,618	$	304	$	(2,201)	$	1,242,721	$	—

The cost, gross unrealized gains and losses, and fair value of those investments classified as equity securities at June 30, 2021 are summarized as follows (in thousands):

	June 30, 2021
			Gross		Gross		Fair
		Cost	Unrealized Gains		Unrealized Losses		Value
Fixed income mutual funds	$	89,962	$	17	$	(81)	$	89,898
Exchange traded mutual funds		30,016		388		—		30,404
Total	$	119,978	$	405	$	(81)	$	120,302

A summary of the amortized cost and fair value of investments classified as available-for-sale, by contractual maturity, as of June 30, 2021 is as follows (in thousands):

	June 30, 2021
		Amortized	Fair
Maturity:		Cost	Value
Within one year	$	717,531	$	717,285
After one through five years		527,087		525,436
Total	$	1,244,618	$	1,242,721