Fair Value of Assets and Liabilities - Narrative (Detail) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2022	Dec. 31, 2021
Quoted Prices in Active Markets for Identical Assets (Level 1) \| Mutual Funds
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investment in mutual funds	$ 38.9	$ 58.1
Carrying amount \| Maximum
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Financial instruments original maturity	90 days

Fair value of investment other than investment in equity security, investment in debt security and equity method investment. Includes, but is not limited to, investment in certain entities that calculate net asset value per share. Example includes, but is not limited to, investment in hedge fund, venture capital fund, private equity fund, and real estate partnership or fund.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 820
-SubTopic 10
-Name Accounting Standards Codification
-Section 35
-Paragraph 54B
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482134/820-10-35-54B

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 820
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 6A
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482106/820-10-50-6A

Name:	us-gaap_AlternativeInvestment
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant