Segment Information - Operating results (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Revenues
Revenues	$ 29,375	$ 24,450	$ 55,726	$ 38,896
Operating income (loss)
Operating income (loss)	450	2,781	117	3,019
Corporate and other business activities	(8,813)	(6,700)	(16,806)	(12,149)
Interest income, net	1,256	259	1,869	491
Other expense, net	(1,200)	(22)	(139)	(473)
Income from continuing operations before income taxes	506	3,018	1,847	3,037
Depreciation and amortization	4,855	3,296	9,856	5,127
Steel Sports [Member]
Revenues
Revenues	2,304	989	2,616	1,145
Operating income (loss)
Operating income (loss)	(585)	(146)	(1,878)	(929)
Depreciation and amortization	172	80	319	220
Total Segment [Member]
Operating income (loss)
Operating income (loss)	2,807	5,522	4,742	8,055
Steel Energy [Member]
Revenues
Revenues	27,071	23,461	53,110	37,751
Operating income (loss)
Operating income (loss)	3,392	5,668	6,620	8,984
Depreciation and amortization	4,683	3,216	9,537	4,907
Corporate [Member]
Operating income (loss)
Corporate and other business activities	$ (2,357)	$ (2,741)	$ (4,625)	$ (5,036)