Earnings per Common Share - Reconciliation of Number of Common Shares Used in Calculating Basic and Diluted Net Earnings Per Share (Detail) - $ / shares	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Earnings Per Share [Abstract]
Weighted Average Number of Shares Outstanding, Basic	16,555,000	16,516,000
Incremental Common Shares Attributable to Dilutive Effect of Share-based Payment Arrangements	59,800	46,951
Weighted Average Number of Shares Outstanding, Diluted	16,615,000	16,563,000
Basic net earnings per common share (in dollars per share)	$ 0.62	$ 0.23
Diluted net earnings per common share (in dollars per share)	$ 0.62	$ 0.23
Anti-dilutive shares excluded from calculation		900,000