Income Taxes - Components of Deferred Income Tax (Details) - USD ($)	Dec. 31, 2019	Dec. 31, 2018
Long-term deferred income tax assets (liabilities), net:
Bad debt	$ 841,000	$ 954,000
Warranty	1,391,000	2,134,000
Other accrued expenses and reserves	1,515,000	511,000
Inventory	2,993,000	2,878,000
Goodwill and intangibles	(22,686,000)	(23,589,000)
Convertible debt	(1,530,000)	(1,225,000)
Fixed assets	(13,421,000)	(3,107,000)
Compensation and benefits	5,965,000	6,268,000
Loss and credit carryforwards	121,602,000	131,896,000
Product liability	3,113,000	2,315,000
State and local taxes	31,499,000	31,345,000
Valuation allowance	(162,790,000)	(174,659,000)
Deferred Tax Liabilities, Leasing Arrangements	9,713,000	0
Other, net	(653,000)	(50,000)
Net Deferred Income Taxes	$ 22,448,000	$ 24,329,000