Investments - Gross Unrealized Gains and Losses and Cost of Equity (Detail) - USD ($) $ in Thousands	Sep. 30, 2022	Dec. 31, 2021
Schedule Of Trading Securities And Other Trading Assets [Line Items]
Equity securities, Cost	$ 50,394	$ 44,175
Equity securities, Gross Unrealized Gains	6,981	19,965
Equity securities	57,375	64,140
Domestic Common Stock [Member]
Schedule Of Trading Securities And Other Trading Assets [Line Items]
Equity securities, Cost	50,394	44,175
Equity securities, Gross Unrealized Gains	6,981	19,965
Equity securities	$ 57,375	$ 64,140

Amount of investment in equity security measured at fair value with change in fair value recognized in net income (FV-NI), classified as current.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(2))
-URI https://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682

Reference 2: http://www.xbrl.org/2003/role/exampleRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section 45
-Paragraph 1
-Subparagraph (f)
-URI https://asc.fasb.org/extlink&oid=124098289&loc=d3e6676-107765

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
-Section 45
-Paragraph 1A
-URI https://asc.fasb.org/extlink&oid=123594786&loc=SL75136599-209740

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Balance Type:	debit
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