GOODWILL AND OTHER INTANGIBLE ASSETS, Intangible Assets Subject to Amortization (Details) $ in Thousands, £ in Millions			6 Months Ended
	Sep. 22, 2014 USD ($)	Sep. 22, 2014 GBP (£)	Jun. 30, 2015 USD ($)
Finite-Lived Intangible Assets [Line Items]
Balance as of December 31, 2014			$ 31,144
Effect of change in foreign currency exchange rates			117
Amortization			(1,469)
Acquisition of business/development			0
Reclassification			(1,805)
Balance as of June 30, 2015			27,987
Corporate [Member]
Finite-Lived Intangible Assets [Line Items]
Balance as of December 31, 2014			22
Effect of change in foreign currency exchange rates			0
Amortization			0
Acquisition of business/development			0
Reclassification			0
Balance as of June 30, 2015			22
Pansend, LLC [Member]
Finite-Lived Intangible Assets [Line Items]
Balance as of December 31, 2014			114
Effect of change in foreign currency exchange rates			0
Amortization			(1)
Acquisition of business/development			0
Reclassification			0
Balance as of June 30, 2015			113
Schuff International, Inc [Member]
Finite-Lived Intangible Assets [Line Items]
Balance as of December 31, 2014			4,304
Effect of change in foreign currency exchange rates			0
Amortization			(149)
Acquisition of business/development			0
Reclassification			0
Balance as of June 30, 2015			4,155
Global Marine Systems Limited [Member]
Finite-Lived Intangible Assets [Line Items]
Balance as of December 31, 2014			9,786
Effect of change in foreign currency exchange rates			117
Amortization			(632)
Acquisition of business/development			0
Reclassification			0
Balance as of June 30, 2015			9,271
American Natural Gas [Member]
Finite-Lived Intangible Assets [Line Items]
Balance as of December 31, 2014			10,918
Effect of change in foreign currency exchange rates			0
Amortization			(528)
Acquisition of business/development			0
Reclassification			0
Balance as of June 30, 2015			10,390
Other [Member]
Finite-Lived Intangible Assets [Line Items]
Balance as of December 31, 2014			6,000
Effect of change in foreign currency exchange rates			0
Amortization			(159)
Acquisition of business/development			0
Reclassification			(1,805)
Balance as of June 30, 2015			4,036
Trade Names [Member]
Finite-Lived Intangible Assets [Line Items]
Balance as of December 31, 2014			11,338
Effect of change in foreign currency exchange rates			13
Amortization			(647)
Acquisition of business/development			0
Reclassification			0
Balance as of June 30, 2015			10,704
Trade Names [Member] \| Corporate [Member]
Finite-Lived Intangible Assets [Line Items]
Balance as of December 31, 2014			0
Effect of change in foreign currency exchange rates			0
Amortization			0
Acquisition of business/development			0
Reclassification			0
Balance as of June 30, 2015			0
Trade Names [Member] \| Pansend, LLC [Member]
Finite-Lived Intangible Assets [Line Items]
Balance as of December 31, 2014			0
Effect of change in foreign currency exchange rates			0
Amortization			0
Acquisition of business/development			0
Reclassification			0
Balance as of June 30, 2015			0
Trade Names [Member] \| Schuff International, Inc [Member]
Finite-Lived Intangible Assets [Line Items]
Balance as of December 31, 2014			4,304
Effect of change in foreign currency exchange rates			0
Amortization			(149)
Acquisition of business/development			0
Reclassification			0
Balance as of June 30, 2015			4,155
Trade Names [Member] \| Global Marine Systems Limited [Member]
Finite-Lived Intangible Assets [Line Items]
Balance as of December 31, 2014			997
Effect of change in foreign currency exchange rates			13
Amortization			(183)
Acquisition of business/development	$ 1,100	£ 0.7	0
Reclassification			0
Balance as of June 30, 2015			827
Trade Names [Member] \| American Natural Gas [Member]
Finite-Lived Intangible Assets [Line Items]
Balance as of December 31, 2014			6,037
Effect of change in foreign currency exchange rates			0
Amortization			(315)
Acquisition of business/development			0
Reclassification			0
Balance as of June 30, 2015			5,722
Trade Names [Member] \| Other [Member]
Finite-Lived Intangible Assets [Line Items]
Balance as of December 31, 2014			0
Effect of change in foreign currency exchange rates			0
Amortization			0
Acquisition of business/development			0
Reclassification			0
Balance as of June 30, 2015			0
Customer Relationships [Member]
Finite-Lived Intangible Assets [Line Items]
Balance as of December 31, 2014			12,214
Effect of change in foreign currency exchange rates			85
Amortization			(465)
Acquisition of business/development			0
Reclassification			0
Balance as of June 30, 2015			11,834
Customer Relationships [Member] \| Corporate [Member]
Finite-Lived Intangible Assets [Line Items]
Balance as of December 31, 2014			0
Effect of change in foreign currency exchange rates			0
Amortization			0
Acquisition of business/development			0
Reclassification			0
Balance as of June 30, 2015			0
Customer Relationships [Member] \| Pansend, LLC [Member]
Finite-Lived Intangible Assets [Line Items]
Balance as of December 31, 2014			0
Effect of change in foreign currency exchange rates			0
Amortization			0
Acquisition of business/development			0
Reclassification			0
Balance as of June 30, 2015			0
Customer Relationships [Member] \| Schuff International, Inc [Member]
Finite-Lived Intangible Assets [Line Items]
Balance as of December 31, 2014			0
Effect of change in foreign currency exchange rates			0
Amortization			0
Acquisition of business/development			0
Reclassification			0
Balance as of June 30, 2015			0
Customer Relationships [Member] \| Global Marine Systems Limited [Member]
Finite-Lived Intangible Assets [Line Items]
Balance as of December 31, 2014			7,333
Effect of change in foreign currency exchange rates			85
Amortization			(252)
Acquisition of business/development			0
Reclassification			0
Balance as of June 30, 2015			7,166
Customer Relationships [Member] \| American Natural Gas [Member]
Finite-Lived Intangible Assets [Line Items]
Balance as of December 31, 2014			4,881
Effect of change in foreign currency exchange rates			0
Amortization			(213)
Acquisition of business/development			0
Reclassification			0
Balance as of June 30, 2015			4,668
Customer Relationships [Member] \| Other [Member]
Finite-Lived Intangible Assets [Line Items]
Balance as of December 31, 2014			0
Effect of change in foreign currency exchange rates			0
Amortization			0
Acquisition of business/development			0
Reclassification			0
Balance as of June 30, 2015			0
Developed Technology [Member]
Finite-Lived Intangible Assets [Line Items]
Balance as of December 31, 2014			1,456
Effect of change in foreign currency exchange rates			19
Amortization			(356)
Acquisition of business/development			0
Reclassification			4,195
Balance as of June 30, 2015			5,314
Developed Technology [Member] \| Corporate [Member]
Finite-Lived Intangible Assets [Line Items]
Balance as of December 31, 2014			0
Effect of change in foreign currency exchange rates			0
Amortization			0
Acquisition of business/development			0
Reclassification			0
Balance as of June 30, 2015			0
Developed Technology [Member] \| Pansend, LLC [Member]
Finite-Lived Intangible Assets [Line Items]
Balance as of December 31, 2014			0
Effect of change in foreign currency exchange rates			0
Amortization			0
Acquisition of business/development			0
Reclassification			0
Balance as of June 30, 2015			0
Developed Technology [Member] \| Schuff International, Inc [Member]
Finite-Lived Intangible Assets [Line Items]
Balance as of December 31, 2014			0
Effect of change in foreign currency exchange rates			0
Amortization			0
Acquisition of business/development			0
Reclassification			0
Balance as of June 30, 2015			0
Developed Technology [Member] \| Global Marine Systems Limited [Member]
Finite-Lived Intangible Assets [Line Items]
Balance as of December 31, 2014			1,456
Effect of change in foreign currency exchange rates			19
Amortization			(197)
Acquisition of business/development	$ 1,600	£ 1.0	0
Reclassification			0
Balance as of June 30, 2015			1,278
Developed Technology [Member] \| American Natural Gas [Member]
Finite-Lived Intangible Assets [Line Items]
Balance as of December 31, 2014			0
Effect of change in foreign currency exchange rates			0
Amortization			0
Acquisition of business/development			0
Reclassification			0
Balance as of June 30, 2015			0
Developed Technology [Member] \| Other [Member]
Finite-Lived Intangible Assets [Line Items]
Balance as of December 31, 2014			0
Effect of change in foreign currency exchange rates			0
Amortization			(159)
Acquisition of business/development			0
Reclassification			4,195
Balance as of June 30, 2015			4,036
Other [Member]
Finite-Lived Intangible Assets [Line Items]
Balance as of December 31, 2014			6,136
Effect of change in foreign currency exchange rates			0
Amortization			(1)
Acquisition of business/development			0
Reclassification			(6,000)
Balance as of June 30, 2015			135
Other [Member] \| Corporate [Member]
Finite-Lived Intangible Assets [Line Items]
Balance as of December 31, 2014			22
Effect of change in foreign currency exchange rates			0
Amortization			0
Acquisition of business/development			0
Reclassification			0
Balance as of June 30, 2015			22
Other [Member] \| Pansend, LLC [Member]
Finite-Lived Intangible Assets [Line Items]
Balance as of December 31, 2014			114
Effect of change in foreign currency exchange rates			0
Amortization			(1)
Acquisition of business/development			0
Reclassification			0
Balance as of June 30, 2015			113
Other [Member] \| Schuff International, Inc [Member]
Finite-Lived Intangible Assets [Line Items]
Balance as of December 31, 2014			0
Effect of change in foreign currency exchange rates			0
Amortization			0
Acquisition of business/development			0
Reclassification			0
Balance as of June 30, 2015			0
Other [Member] \| Global Marine Systems Limited [Member]
Finite-Lived Intangible Assets [Line Items]
Balance as of December 31, 2014			0
Effect of change in foreign currency exchange rates			0
Amortization			0
Acquisition of business/development			0
Reclassification			0
Balance as of June 30, 2015			0
Other [Member] \| American Natural Gas [Member]
Finite-Lived Intangible Assets [Line Items]
Balance as of December 31, 2014			0
Effect of change in foreign currency exchange rates			0
Amortization			0
Acquisition of business/development			0
Reclassification			0
Balance as of June 30, 2015			0
Other [Member] \| Other [Member]
Finite-Lived Intangible Assets [Line Items]
Balance as of December 31, 2014			6,000
Effect of change in foreign currency exchange rates			0
Amortization			0
Acquisition of business/development			0
Reclassification			(6,000)
Balance as of June 30, 2015			$ 0