CONDENSED CONSOLIDATED STATEMENTS OF CHANGES IN STOCKHOLDERS' EQUITY - UNAUDITED - (Parenthetical) - $ / shares	3 Months Ended
Mar. 31, 2020	Mar. 31, 2019
Statement Of Stockholders Equity [Abstract]
Common stock dividends, per share	$ 0.30	$ 0.28
Stock option plan, shares	6,013	6,755
Employee stock purchase plan, shares	8,617	7,662
Restricted stock, shares		11,959
Treasury stock purchased	820,328

Aggregate dividends paid during the period for each share of common stock outstanding.

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Number of shares issued during the period as a result of an employee stock purchase plan.

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