Condensed Consolidated Statements of Operations and Comprehensive Loss - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Statement of Comprehensive Income [Abstract]
Net sales	$ 79,535	$ 136,113	$ 290,857	$ 433,570
Costs and expenses:
Cost of materials (exclusive of depreciation)	58,610	103,019	211,806	323,918
Warehouse, processing and delivery expense	13,394	18,759	45,584	59,577
Sales, general and administrative expense	13,515	16,048	41,815	49,027
Depreciation expense	1,921	2,055	6,035	6,306
Impairment of goodwill	2,676	0	2,676	0
Total costs and expenses	90,116	139,881	307,916	438,828
Operating loss	(10,581)	(3,768)	(17,059)	(5,258)
Interest expense, net	5,077	10,204	20,146	29,503
Unrealized gain on embedded debt conversion option	0	0	(2,010)	0
Other income, net	(342)	(697)	(2,194)	(4,779)
Loss before income taxes	(15,316)	(13,275)	(33,001)	(29,982)
Income tax benefit	(572)	(1,079)	(3,163)	(1,479)
Net loss	$ (14,744)	$ (12,196)	$ (29,838)	$ (28,503)
Basic and diluted loss per common share (in usd per share)	$ (0.20)	$ (5.49)	$ (0.59)	$ (13.11)
Comprehensive loss:
Net loss	$ (14,744)	$ (12,196)	$ (29,838)	$ (28,503)
Change in unrecognized pension and postretirement benefit costs, net of tax	25	23	75	69
Foreign currency translation adjustments, net of tax	1,284	(1,068)	372	(1,811)
Comprehensive loss	$ (13,435)	$ (13,241)	$ (29,391)	$ (30,245)