Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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+ Details

- Definition

Amount of equity (deficit) attributable to parent. Excludes temporary equity and equity attributable to noncontrolling interest.

+ References

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+ Details

Comprehensive (Loss) Income - Summary of Components of Accumulated Other Comprehensive Income (Loss) (Detail) - USD ($) $ in Thousands	Jun. 30, 2026	Mar. 31, 2026	Dec. 31, 2025	Jun. 30, 2025	Mar. 31, 2025	Dec. 31, 2024
Accumulated Other Comprehensive Income (Loss) [Line Items]
Total shareholders’ equity	$ 1,343,593	$ 1,324,026	$ 1,328,001	$ 1,266,823	$ 1,255,519	$ 1,220,907
AOCI attributable to parent
Accumulated Other Comprehensive Income (Loss) [Line Items]
Total shareholders’ equity	(101,789)	$ (99,250)	(94,605)	$ (121,356)	$ (130,364)	$ (152,462)
Net unrealized loss on available for sale securities
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive income, before tax	(161,681)		(151,481)
Accumulated other comprehensive income, tax effect	47,799		44,783
Total shareholders’ equity	(113,882)		(106,698)
Unfunded status of the supplemental retirement plans
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive income, before tax	16,129		16,129
Accumulated other comprehensive income, tax effect	(4,768)		(4,768)
Total shareholders’ equity	11,361		11,361
Joint beneficiary agreement liability
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive income, before tax	732		732
Accumulated other comprehensive income, tax effect	0		0
Total shareholders’ equity	$ 732		$ 732