Consolidated Statements of Changes in Stockholders' Equity (Parenthetical) - $ / shares	12 Months Ended
Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Consolidated Statements of Changes in Stockholders' Equity [Abstract]
Cash dividends - per share (in dollars per share)	$ 1.08	$ 1.05	$ 0.99
Purchase of treasury shares (in shares)	263,507
Net issuance of shares to employee benefit plans and other stock plans (in shares)	95,990	123,645	130,157

Number of shares that have been repurchased during the period and are being held in treasury.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
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Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
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-Section S99
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Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
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Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration