Schedule III - Supplemental Financial Information - Quarterly Results of Operations (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands		3 Months Ended																12 Months Ended
		Dec. 31, 2019		Sep. 30, 2019		Jun. 30, 2019		Mar. 31, 2019		Dec. 31, 2018		Sep. 30, 2018		Jun. 30, 2018		Mar. 31, 2018		Dec. 31, 2019		Dec. 31, 2018		Dec. 31, 2017
Net sales		$ 319,740		$ 384,230		$ 429,151		$ 445,919		$ 429,590		$ 456,976		$ 452,917		$ 375,598		$ 1,579,040		$ 1,715,081		$ 1,330,696
Operating income (a)		1,015	[1]	3,581	[1]	5,940	[1]	6,074	[1]	1,774	[2]	18,614	[2]	24,319	[2]	12,345	[2]	16,610	[1]	57,052	[2]	23,986
Income (loss) before income taxes		(1,288)		1,024		2,707		2,846		(1,512)		15,708		21,556		10,313		5,289		46,065
Net income (loss)		$ (890)		$ 591		$ 2,081		$ 2,074		$ (1,316)		$ 11,599		$ 15,848		$ 7,629		$ 3,856		$ 33,759		$ 18,963
Basic net income (loss) per share (in dollars per share)		$ (0.08)		$ 0.05		$ 0.18		$ 0.18		$ (0.11)		$ 1.01		$ 1.39		$ 0.67		$ 0.34		$ 2.95		$ 1.67
Weighted average shares outstanding - basic (in shares)		11,416		11,420		11,415		11,488		11,444		11,444		11,435		11,418		11,509		11,432		11,381
Diluted net income (loss) per share (in dollars per share)		$ (0.08)		$ 0.05		$ 0.18		$ 0.18		$ (0.11)		$ 1.01		$ 1.39		$ 0.67		$ 0.34		$ 2.95		$ 1.67
Weighted average shares outstanding - diluted (in shares)		11,416		11,420		11,415		11,488		11,444		11,446		11,435		11,418		11,509		11,440		11,381
Market price of common stock: (b)
Net sales		$ 319,740		$ 384,230		$ 429,151		$ 445,919		$ 429,590		$ 456,976		$ 452,917		$ 375,598		$ 1,579,040		$ 1,715,081		$ 1,330,696
Operating income (a)		1,015	[1]	3,581	[1]	5,940	[1]	6,074	[1]	1,774	[2]	18,614	[2]	24,319	[2]	12,345	[2]	16,610	[1]	57,052	[2]	23,986
Income (loss) before income taxes		(1,288)		1,024		2,707		2,846		(1,512)		15,708		21,556		10,313		5,289		46,065
Net income (loss)		$ (890)		$ 591		$ 2,081		$ 2,074		$ (1,316)		$ 11,599		$ 15,848		$ 7,629		$ 3,856		$ 33,759		$ 18,963
Basic net income (loss) per share (in dollars per share)		$ (0.08)		$ 0.05		$ 0.18		$ 0.18		$ (0.11)		$ 1.01		$ 1.39		$ 0.67		$ 0.34		$ 2.95		$ 1.67
Weighted average shares outstanding - basic (in shares)		11,416		11,420		11,415		11,488		11,444		11,444		11,435		11,418		11,509		11,432		11,381
Diluted net income (loss) per share (in dollars per share)		$ (0.08)		$ 0.05		$ 0.18		$ 0.18		$ (0.11)		$ 1.01		$ 1.39		$ 0.67		$ 0.34		$ 2.95		$ 1.67
Weighted average shares outstanding - diluted (in shares)		11,416		11,420		11,415		11,488		11,444		11,446		11,435		11,418		11,509		11,440		11,381
Maximum [Member]
Market price of common stock: (b)
Market price of common stock (in dollars per share)	[3]	$ 18.41		$ 16.28		$ 18.24		$ 20.24		$ 21.41		$ 24.23		$ 24.27		$ 25.84		$ 20.24		$ 25.84
Minimum [Member]
Market price of common stock: (b)
Market price of common stock (in dollars per share)	[3]	$ 13.53		$ 9.99		$ 12.09		$ 14		$ 13.72		$ 19.92		$ 19.75		$ 19.75		$ 9.99		$ 13.72

[1] Operating income (loss) in 2019 includes $3,669 of LIFO income related to the Company's tubular and pipe products segment.

[2] Operating income (loss) in 2018 includes $8,408 of LIFO expense related to the Company's tubular and pipe products segment.

[3] Represents the high and low sales prices of our common stock as reported by the Nasdaq Global Select Market.