Condensed Consolidated Statements of Operations and Comprehensive Loss - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Statement of Comprehensive Income [Abstract]
Net sales	$ 136,113	$ 148,109	$ 433,570	$ 444,396
Costs and expenses:
Cost of materials (exclusive of depreciation)	103,019	110,896	323,918	331,861
Warehouse, processing and delivery expense	18,759	21,092	59,577	62,612
Sales, general and administrative expense	16,048	16,871	49,027	50,393
Depreciation expense	2,055	2,227	6,306	6,965
Total costs and expenses	139,881	151,086	438,828	451,831
Operating loss	(3,768)	(2,977)	(5,258)	(7,435)
Interest expense, net	10,204	8,746	29,503	24,001
Other income, net	(697)	(3,000)	(4,779)	(7,101)
Loss before income taxes	(13,275)	(8,723)	(29,982)	(24,335)
Income tax benefit	(1,079)	(2,068)	(1,479)	(4,026)
Net loss	$ (12,196)	$ (6,655)	$ (28,503)	$ (20,309)
Basic and diluted loss per common share (in usd per share)	$ (5.49)	$ (3.33)	$ (13.11)	$ (10.15)
Comprehensive loss:
Net loss	$ (12,196)	$ (6,655)	$ (28,503)	$ (20,309)
Change in unrecognized pension and postretirement benefit costs, net of tax	23	0	69	0
Foreign currency translation adjustments, net of tax	(1,068)	(1,014)	(1,811)	(3,013)
Comprehensive loss	$ (13,241)	$ (7,669)	$ (30,245)	$ (23,322)