Summary of Treasury Stock Activity (Detail) $ in Thousands	9 Months Ended
	Sep. 30, 2021 USD ($) shares
Treasury Stock Shares [Abstract]
Beginning Balance, Shares | shares	5,050,981
Restricted stock withholdings | shares	565	[1]
Restricted stock forfeitures | shares	42,034
Ending Balance, Shares | shares	5,093,580
Beginning Balance, Cost | $	$ 87,004
Restricted stock withholdings | $	16	[1]
Restricted stock forfeitures | $	0
Ending Balance, Cost | $	$ 87,020

[1] The Company withheld restricted shares as a result of the election by certain employees to satisfy their tax liabilities upon vesting in restricted stock and restricted stock units. The Company determined the number of shares to be withheld based upon market values ranging from $17.41 to $24.14 per share.