Earnings Per Share (EPS) - Schedule of Reconciliation of Weighted Average Shares Used in the Diluted EPS (Detail) - shares	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Earnings Per Share [Line Items]
Weighted average common shares-basic	19,267,920	18,903,289	18,494,002
Effect of diluted securities:
Weighted average common shares-diluted	19,391,718	18,903,289	18,911,610
Stock Options And Employee Stock Purchase Plan [Member]
Effect of diluted securities:
Effect of diluted securities	51,951		313,648
Time-Based Restricted Stock Awards [Member]
Effect of diluted securities:
Effect of diluted securities	71,847
Performance-based Restricted Stock Awards [Member]
Effect of diluted securities:
Effect of diluted securities			103,960