Fair Value Measurements - Assets Measured at Fair Value on Recurring Basis (Details) - Recurring [Member] - USD ($) $ in Thousands	Jun. 30, 2022	Dec. 31, 2021
Equity Security [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Fair value assets	$ 2,876	$ 5,150
Equity Mutual Fund [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Fair value assets	16,090	9,523
Commodity Mutual Fund [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Fair value assets	211	249
Derivative Contract Asset [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Fair value assets		1,245
U.S. Treasury Mutual Funds [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Fair value assets	12,898	12,889
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Equity Security [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Fair value assets	2,876	416
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Derivative Contract Asset [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Fair value assets		1,245
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | U.S. Treasury Mutual Funds [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Fair value assets	12,898	12,889
Significant Other Observable Inputs (Level 2) [Member] | Equity Security [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Fair value assets		4,734
Significant Other Observable Inputs (Level 2) [Member] | Equity Mutual Fund [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Fair value assets	16,090	9,523
Significant Other Observable Inputs (Level 2) [Member] | Commodity Mutual Fund [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Fair value assets	$ 211	$ 249