Stock Compensation Plans - Tax benefits realized (Details) - USD ($) $ in Thousands	9 Months Ended
Sep. 30, 2020	Sep. 30, 2019
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Proceeds of options exercised		$ 191
Related tax benefit recognized	$ 40	4
Intrinsic value of options exercised	$ 189	$ 390

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Amount of tax benefit for recognition of expense of award under share-based payment arrangement.

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-Publisher FASB
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Amount of cash inflow from exercise of option under share-based payment arrangement.

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-Publisher FASB
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Amount of accumulated difference between fair value of underlying shares on dates of exercise and exercise price on options exercised (or share units converted) into shares.

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