Earnings Per Share - Schedule of Earnings Per Share, Basic and Diluted (Detail) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Earnings Per Share [Abstract]
Net income	$ 14,532	$ 17,882
Weighted average shares outstanding - basic (in shares)	5,124,478	5,122,206
Weighted average shares outstanding - diluted (in shares)	5,124,478	5,122,206
Net income per common share - basic (in usd per share)	$ 2.84	$ 3.49
Net income per common share - diluted (in usd per share)	$ 2.84	$ 3.49