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Investments - Contractual Maturities of Debt Securities and Other Investments (Detail) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale debt securities, Fair Value/Carrying Value	$ 29,558	$ 30,066
Corporate Bonds [Member]
Schedule of Available-for-sale Securities [Line Items]
Less than one year	295
One to two years	5,965
Two to three years	2,596
Three to five years	238
Available-for-sale debt securities, Fair Value/Carrying Value	9,094	10,747
Municipal Fixed-Rate Bonds [Member]
Schedule of Available-for-sale Securities [Line Items]
Less than one year	269
One to two years	1,265
Two to three years	113
Available-for-sale debt securities, Fair Value/Carrying Value	1,647	1,551
Asset-Backed Bonds [Member]
Schedule of Available-for-sale Securities [Line Items]
Three to five years	49
More than ten years	258
Available-for-sale debt securities, Fair Value/Carrying Value	307	322
Mortgage/Agency-Backed Bonds [Member]
Schedule of Available-for-sale Securities [Line Items]
Less than one year	1,050
One to two years	479
Two to three years	289
Three to five years	371
Five to ten years	915
More than ten years	1,458
Available-for-sale debt securities, Fair Value/Carrying Value	4,562	4,736
U.S. Government Bonds [Member]
Schedule of Available-for-sale Securities [Line Items]
Less than one year	979
One to two years	4,800
Two to three years	7,106
Three to five years	669
Available-for-sale debt securities, Fair Value/Carrying Value	13,554	12,171
Foreign Government Bonds [Member]
Schedule of Available-for-sale Securities [Line Items]
Two to three years	394
Available-for-sale debt securities, Fair Value/Carrying Value	$ 394	$ 539

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