Fair Value Measurements (Financial Assets Measured at Fair Value on a Recurring Basis) (Detail) - USD ($) $ in Thousands	Sep. 30, 2022	Dec. 31, 2021
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Financial assets fair value	$ 10,656	$ 30,494
Cash and Cash Equivalents | Cash
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Financial assets fair value	9,156	27,109
Amortized Cost	9,156	27,109
Securities Investment [Member] | Equity Securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Financial assets fair value		1,755
Restricted Cash Equivalents And Investments [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Financial assets fair value	1,500	1,630
Amortized Cost	1,500	1,630
Level 1
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Financial assets fair value	10,656	28,739
Level 1 | Cash and Cash Equivalents | Cash
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Financial assets fair value	9,156	27,109
Level 1 | Securities Investment [Member] | Equity Securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Financial assets fair value		0
Level 1 | Restricted Cash Equivalents And Investments [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Financial assets fair value	1,500	1,630
Level 2
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Financial assets fair value	0	0
Level 2 | Cash and Cash Equivalents | Cash
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Financial assets fair value	0	0
Level 2 | Securities Investment [Member] | Equity Securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Financial assets fair value		0
Level 2 | Restricted Cash Equivalents And Investments [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Financial assets fair value	0	0
Level 3
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Financial assets fair value	0	1,755
Level 3 | Cash and Cash Equivalents | Cash
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Financial assets fair value	0	0
Level 3 | Securities Investment [Member] | Equity Securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Financial assets fair value		1,755
Level 3 | Restricted Cash Equivalents And Investments [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Financial assets fair value	$ 0	$ 0