Credit Agreement - Schedule of Credit Agreement (Detail) - Credit Agreement [Member] - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2023	Dec. 31, 2022
Credit Agreement:
Credit facility remaining availability		$ 124,133	$ 124,113
Outstanding letters of credit		867	887
Availability of additional letters of credit	[1]	$ 124,133	$ 124,113
Line of credit facility, interest rate		0.00%	0.00%
Commitment fee rate		0.30%	0.30%
Letter of credit fee rate	[2]	7.50%	6.50%

[1] The letters of credit availability under the credit agreement with Wintrust is up to the borrowing limit of $125.0 million.

[2] The letter of credit fee rate is based on prime minus 1.0%, subject to a minimum rate of 3.0%. The prime rate as of December 31, 2023 was 8.50%, which would yield a 7.50% fee rate, which is reflected in the table above