Income Taxes, Primary Factors Affecting Income Tax Rates (Details) - USD ($)	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Primary Factors Affecting Income Tax Rates [Abstract]
Tax benefit at U.S. statutory rates	(21.00%)	(21.00%)
State tax benefit	(3.40%)	4.20%
Permanent differences	0.90%	0.50%
Other	2.30%	(1.40%)
Changes in valuation allowance	21.20%	17.70%
Income tax rate, total	0.00%	0.00%
Federal and Sate [Abstract]
Deferred tax asset valuation allowance percentage in each of the last two years	100.00%
Operating loss carryforwards expiration year	2037
Federal and state research and development credits expiration year	2042
Federal [Member]
Federal and Sate [Abstract]
Research and development credits	$ 5,214,000
Federal [Member] | Expiring as a Result of 2017 Tax Act [Member]
Federal and Sate [Abstract]
Net operating loss carryforwards	116,781,000
Federal [Member] | Expiring Through 2037 [Member]
Federal and Sate [Abstract]
Net operating loss carryforwards	127,039,000
State [Member]
Federal and Sate [Abstract]
Research and development credits	1,262,000
State [Member] | Expiring as a Result of 2017 Tax Act [Member]
Federal and Sate [Abstract]
Net operating loss carryforwards	123,081,000
State [Member] | Expiring Through 2037 [Member]
Federal and Sate [Abstract]
Net operating loss carryforwards	$ 102,003,000