Stock-Based Compensation - Information about Options Exercised (Detail) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Share Based Compensation Arrangement By Share Based Payment Award Options Activity [Abstract]
Options exercised	0	30,000	60,000
Total intrinsic value of exercised options	$ 0	$ 1,319	$ 1,376
Tax benefits realized	$ 0	$ 509	$ 501

Share based compensation arrangement by share based payment award options activity.

No definition available.

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- Definition

Amount of tax benefit from exercise of stock options granted under share-based compensation arrangement.

+ References

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-Publisher FASB
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- Definition

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.

+ References

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- Definition

Number of share options (or share units) exercised during the current period.

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