Condensed Consolidated Statements Of Shareholders' Equity (Parenthetical) - USD ($) $ in Thousands	3 Months Ended
Mar. 31, 2024	Dec. 31, 2023	Sep. 30, 2023	Mar. 31, 2023	Dec. 31, 2022	Sep. 30, 2022
Statement of Stockholders' Equity [Abstract]
Tax effect included in net pension and postretirement benefit gains	$ 23	$ 23	$ 23	$ 28	$ 30	$ 29
Common stock, dividends per share (in dollars per share)	$ 0.90	$ 0.90	$ 0.85	$ 0.85	$ 0.85	$ 0.80

Amount, after reclassification adjustment, of tax (expense) benefit for (increase) decrease in accumulated other comprehensive income of defined benefit plan.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Section 45
-Paragraph 10A
-Subparagraph (i-k)
-SubTopic 10
-Topic 220
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482790/220-10-45-10A

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Section 45
-Paragraph 12
-SubTopic 10
-Topic 220
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482790/220-10-45-12

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Topic 810
-SubTopic 10
-Name Accounting Standards Codification
-Section 45
-Paragraph 19
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481231/810-10-45-19

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