Consolidated Statements of Cash Flows - USD ($)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Cash flows from operating activities
Net loss	$ (75,238,000)	$ (40,581,000)
Adjustments to reconcile net loss to net cash flows used in operating activities:
Restructuring and impairment charges	22,371,000	0
Net proceeds from Shoals transaction		2,655,000
Depreciation and amortization	12,438,000	12,017,000
Amortization expense - right-of-use leased assets	10,485,000
Recognition of deferred income from state and local incentives	(2,219,000)	(2,220,000)
Loss on sale of railcars available for lease	7,197,000
Gain on termination of postretirement benefit plan	(6,637,000)
Deferred income taxes	176,000	9,969,000
Stock-based compensation recognized	1,225,000	3,198,000
Other non-cash items, net	(975,000)	(304,000)
Changes in operating assets and liabilities, net of acquisitions:
Accounts receivable	11,227,000	(10,637,000)
Inventories	40,649,000	(16,311,000)
Other assets	(2,127,000)	1,728,000
Accounts and contractual payables	(23,961,000)	10,693,000
Accrued payroll and employee benefits	(1,368,000)	(165,000)
Income taxes receivable/payable	155,000	657,000
Accrued warranty	(921,000)	1,247,000
Lease liability	(17,602,000)
Other liabilities	6,201,000	(2,461,000)
Accrued pension costs and accrued postretirement benefits	(55,000)	(1,129,000)
Net cash flows used in operating activities	(18,979,000)	(31,644,000)
Cash flows from investing activities
Purchase of restricted certificates of deposit	(4,981,000)	(8,312,000)
Maturity of restricted certificates of deposit	6,164,000	9,080,000
Purchase of securities held to maturity	(1,986,000)	(111,356,000)
Proceeds from maturity of securities	20,025,000	136,716,000
Cost of railcars available for lease		(37,347,000)
Purchase of property, plant and equipment	(5,573,000)	(2,185,000)
Proceeds from sale of property, plant and equipment and railcars available for lease	17,305,000	2,458,000
Net cash flows provided by (used in) investing activities	30,954,000	(10,946,000)
Cash flows from financing activities
Proceeds from line of credit borrowings	10,200,000
Employee stock settlement	(59,000)	(118,000)
Deferred financing costs	(929,000)	(10,000)
Net cash flows provided by (used in) financing activities	9,212,000	(128,000)
Net increase (decrease) in cash and cash equivalents	21,187,000	(42,718,000)
Cash, cash equivalents and restricted cash equivalents at beginning of year	45,070,000	87,788,000
Cash, cash equivalents and restricted cash equivalents at end of year	66,257,000	45,070,000
Supplemental cash flow information
Interest paid	196,000	68,000
Income tax refunds received	1,057,000	599,000
Income tax paid	$ 79,000	$ 5,000