Fair Value Measurement (Tables)

12 Months Ended

Dec. 31, 2021

Fair Value Disclosures [Abstract]

Assets (liabilities) measured at fair value

A summary of assets (liabilities) measured at fair value is as follows:

	As of December 31, 2021
	Total		Level 1		Level 2		Level 3
Commercial paper	$	116,902	$	—	$	116,902	$	—
Corporate bonds	$	329,777	—		329,777		—
Municipal bonds	$	11,906	—		11,906		—
Commodity contract derivatives	$	(1,459)	(366)		(1,093)		—
	$	457,126	$	(366)	$	457,492	$	—

	As of December 31, 2020
	Total		Level 1		Level 2		Level 3
Commercial paper	$	48,714	$	—	$	48,714	$	—
Corporate bonds	$	169,998	—		169,998		—
U.S. Treasury bills	$	44,992	44,992		—		—
Municipal bonds	$	5,839	—		5,839		—
Commodity contract derivatives	$	(8,706)	(3,069)		(5,637)		—
	$	260,837	$	41,923	$	218,914	$	—

Estimated fair values of the Company's financial instruments

The estimated fair values of the Company’s financial instruments, which are not recorded at fair value are as follows as of December 31:

	2021				2020
	Asset (Liability) Carrying Amount		Estimated Fair Value		Asset (Liability) Carrying Amount		Estimated Fair Value
Financial Liabilities:
Debt and lines of credit	$	(550,000)	$	(552,877)	$	(66,977)	$	(418,107)