XML 69 R110.htm IDEA: XBRL DOCUMENT v3.19.3.a.u2
Stock Options and Other Equity-Based Incentive Instruments - Summary of Compensation Costs and Excess Tax Benefits for RSUs (Detail) - USD ($)
12 Months Ended
Dec. 31, 2019
Dec. 31, 2018
Dec. 31, 2017
Service Condition Vesting RSUs      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Total compensation costs for RSUs recognized in income $ 1,161,237 $ 1,017,000 $ 895,000
Excess tax benefit recognized in income Service condition vesting RSUs 141,000 104,000 131,000
Market Plus Service Condition Vesting RSUs      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Total compensation costs for RSUs recognized in income 493,000 370,000 432,000
Excess tax benefit recognized in income Service condition vesting RSUs $ 146,000 $ 191,000 $ 175,000