Basis of Presentation of Interim Period Statements - Summary of Basic and Diluted Common Shares Outstanding (Detail) - shares shares in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Weighted Average Number Of Shares Outstanding Diluted Disclosure Items [Abstract]
Weighted average number of basic shares outstanding	7,554	7,557	7,565	7,539
Effect of dilutive securities	91	90	93	139
Weighted average number of diluted shares outstanding	7,645	7,647	7,658	7,678