Fair Value Measurements (Tables)

12 Months Ended

Dec. 31, 2022

Fair Value Measurements [Abstract]

Assets Measured at Fair Value on a Recurring Basis

The following tables present the major security types we held at December 31, 2022 and 2021 that we regularly measure and carry at fair value. As of December 31, 2022, we did not have any investments that we valued using Level 3 inputs. The following tables segregate each security type by the level within the fair value hierarchy of the valuation techniques we utilized to determine the respective securities’ fair value (in thousands):

	At December 31, 2022		Quoted Prices in Active Markets (Level 1)		Significant Other Observable Inputs (Level 2)
Cash equivalents (1)	$	211,655	$	211,655	$	—
Corporate debt securities (3)		726,950		—		726,950
Debt securities issued by U.S. government agencies (2)		165,055		—		165,055
Debt securities issued by the U.S. Treasury (2)		748,475		748,475		—
Debt securities issued by states of the U.S. and political subdivisions of the states (2)		74,917		—		74,917
Other municipal debt securities (2)		5,994		—		5,994
Publicly traded equity securities included in other current assets (4)		10,539		10,539		—
Total	$	1,943,585	$	970,669	$	972,916

	At December 31, 2021		Quoted Prices in Active Markets (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)
Cash equivalents (1)	$	541,199	$	541,199	$	—	$	—
Corporate debt securities (2)		764,059		—		764,059		—
Debt securities issued by U.S. government agencies (2)		120,868		—		120,868		—
Debt securities issued by the U.S. Treasury (2)		182,634		182,634		—		—
Debt securities issued by states of the U.S. and political subdivisions of the states (5)		174,464		—		174,464		—
Other municipal debt securities (2)		6,099		—		6,099		—
Publicly traded equity securities included in other current assets (4)		18,205		3,875		—		14,330
Total	$	1,807,528	$	727,708	$	1,065,490	$	14,330

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(1) Included in cash and cash equivalents in our consolidated balance sheets.

(2) Included in short-term investments.

(3) $11.0 million included in cash and cash equivalents in our consolidated balance sheets, with the difference included in short-term investments in our consolidated balance sheets.

(4) Included in other current assets in our consolidated balance sheets.

(5) $2.3 million included in cash and cash equivalents in our consolidated balance sheets, with the difference included in short-term investments in our consolidated balance sheets.