Income Taxes (Narrative) (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Operating loss not subject to expiration	$ 113,100,000
Valuation allowance	6,300,000
Unrecognized tax benefits	0	$ 0
Interest and penalties pertaining to income tax examination recognized	$ 0	$ 0
U.S. federal statutory income tax rate	21.00%	21.00%
Domestic Tax Authority [Member]
Net operating loss carryforwards ("NOLs")	$ 167,600,000
State and Local Jurisdiction [Member]
Net operating loss carryforwards ("NOLs")	$ 118,900,000