Income Taxes - Narrative (Details) - USD ($)	Dec. 31, 2022	Dec. 31, 2021
Income Tax Disclosure [Abstract]
Deferred tax assets (liabilities) related to net unrealized holdings losses/(gains) in the available-for-sale securities portfolio	$ 58,600,000	$ 4,700,000
Deferred tax assets related to employee benefit plans	9,800,000	13,400,000
Valuation allowance	$ 0	$ 0

Amount of deferred tax assets for which it is more likely than not that a tax benefit will not be realized.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)
-URI https://asc.fasb.org/extlink&oid=121826272&loc=d3e32537-109319

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant