Investments - Cash Equivalents and Investments held at Fair Value (Detail) - USD ($) $ in Thousands	Jun. 30, 2022	Dec. 31, 2021
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale debt securities	$ 29,272	$ 30,066
Marketable equity securities	1,000	1,000
Fair Value, Measurements [Member]
Schedule of Available-for-sale Securities [Line Items]
Total	53,121	70,259
Fair Value, Measurements [Member] \| Quoted Prices in Active Market for Identical Assets (Level 1) [Member]
Schedule of Available-for-sale Securities [Line Items]
Total	35,633	52,364
Fair Value, Measurements [Member] \| Significant Other Observable Inputs (Level 2) [Member]
Schedule of Available-for-sale Securities [Line Items]
Total	17,488	17,895
Money Market Funds [Member] \| Fair Value, Measurements [Member]
Schedule of Available-for-sale Securities [Line Items]
Cash equivalents	409	652
Money Market Funds [Member] \| Fair Value, Measurements [Member] \| Quoted Prices in Active Market for Identical Assets (Level 1) [Member]
Schedule of Available-for-sale Securities [Line Items]
Cash equivalents	409	652
Corporate Bonds [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale debt securities	10,569	10,747
Corporate Bonds [Member] \| Fair Value, Measurements [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale debt securities	10,569	10,747
Corporate Bonds [Member] \| Fair Value, Measurements [Member] \| Significant Other Observable Inputs (Level 2) [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale debt securities	10,569	10,747
Municipal Fixed-Rate Bonds [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale debt securities	1,514	1,551
Municipal Fixed-Rate Bonds [Member] \| Fair Value, Measurements [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale debt securities	1,514	1,551
Municipal Fixed-Rate Bonds [Member] \| Fair Value, Measurements [Member] \| Significant Other Observable Inputs (Level 2) [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale debt securities	1,514	1,551
Asset-Backed Bonds [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale debt securities	1,003	322
Asset-Backed Bonds [Member] \| Fair Value, Measurements [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale debt securities	1,003	322
Asset-Backed Bonds [Member] \| Fair Value, Measurements [Member] \| Significant Other Observable Inputs (Level 2) [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale debt securities	1,003	322
Mortgage/Agency-Backed Bonds [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale debt securities	4,014	4,736
Mortgage/Agency-Backed Bonds [Member] \| Fair Value, Measurements [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale debt securities	4,014	4,736
Mortgage/Agency-Backed Bonds [Member] \| Fair Value, Measurements [Member] \| Significant Other Observable Inputs (Level 2) [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale debt securities	4,014	4,736
U.S. Government Bonds [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale debt securities	11,784	12,171
U.S. Government Bonds [Member] \| Fair Value, Measurements [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale debt securities	11,784	12,171
U.S. Government Bonds [Member] \| Fair Value, Measurements [Member] \| Quoted Prices in Active Market for Identical Assets (Level 1) [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale debt securities	11,784	12,171
Foreign Government Securities / Bonds [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale debt securities	388	539
Foreign Government Securities / Bonds [Member] \| Fair Value, Measurements [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale debt securities	388	539
Foreign Government Securities / Bonds [Member] \| Fair Value, Measurements [Member] \| Significant Other Observable Inputs (Level 2) [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale debt securities	388	539
Marketable Equity Securities - Various Industries [Member] \| Fair Value, Measurements [Member]
Schedule of Available-for-sale Securities [Line Items]
Marketable equity securities	873	12,606
Marketable Equity Securities - Various Industries [Member] \| Fair Value, Measurements [Member] \| Quoted Prices in Active Market for Identical Assets (Level 1) [Member]
Schedule of Available-for-sale Securities [Line Items]
Marketable equity securities	873	12,606
Deferred Compensation Plan Assets [Member] \| Fair Value, Measurements [Member]
Schedule of Available-for-sale Securities [Line Items]
Marketable equity securities	22,567	26,935
Deferred Compensation Plan Assets [Member] \| Fair Value, Measurements [Member] \| Quoted Prices in Active Market for Identical Assets (Level 1) [Member]
Schedule of Available-for-sale Securities [Line Items]
Marketable equity securities	$ 22,567	$ 26,935

Fair value portion of probable future economic benefits obtained or controlled by an entity as a result of past transactions or events.

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