Business Acquisition - Pro Forma Information (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Business Acquisition [Line Items]
Contract revenues	$ 137,061	$ 106,976	$ 304,607	$ 278,485
Costs of contract revenues	128,783	94,070	281,848	252,060
Gross profit	8,278	12,906	22,759	26,425
Selling, general and administrative expenses	14,496	7,859	31,982	23,953
(Loss) income from operations	(6,218)	5,047	(9,223)	2,472
(Loss) gain from sale of assets, net	(2,107)	(12)	(2,007)	165
Other income	190	1	190	467
Interest expense	(943)	(198)	(1,433)	(523)
Interest income	13	0	30	12
Other (expense) income, net	(2,847)	(209)	(3,220)	121
(Loss) income before income taxes	(9,065)	4,838	(12,443)	2,593
Income tax (benefit) expense	(1,669)	1,876	(2,945)	1,006
Net (loss) income attributable to Orion common stockholders	$ (7,396)	$ 2,962	$ (9,498)	$ 1,587
Basic (loss) income per share (in dollars per share)	$ (0.27)	$ 0.11	$ (0.35)	$ 0.06
Diluted (loss) income per share (in dollars per share)	$ (0.27)	$ 0.11	$ (0.35)	$ 0.06
Basic (shares)	27,243,128	27,468,240	27,397,342	27,430,162
Diluted (shares)	27,243,128	27,802,734	27,397,342	27,809,208
Business Acquisition, Pro Forma Information [Abstract]
Business acquisition, pro forma revenue			$ 440,646	$ 449,027
Business acquisition, pro forma cost of contract revenue			394,520	396,309
Business acquisition, pro forma gross profit			46,126	52,718
Business acquisition, pro forma selling, general and administrative			44,322	36,262
Business acquisition, pro forma operating income (loss)			1,804	16,456
Business acquisition, pro forma gain (loss) on disposition of assets			(1,515)	194
Business acquisition, pro forma non-operating income (expense)			1,980	1,204
Business acquisition, pro forma interest expense			(1,892)	(776)
Business acquisition, pro forma interest income, deposits with financial institutions			30	288
Business acquisition, pro forma other nonoperating income (expense)			(1,397)	910
Business acquisition, pro forma income (loss) from continuing operations before income taxes, extraordinary items, noncontrolling interest			407	17,366
Business acquisition, pro forma income tax expense (benefit)			(2,945)	1,006
Business acquisition, pro forma net income (loss)			$ (2,538)	$ 16,360
Business acquisition, pro forma earnings per share, basic (USD per share)			$ (0.09)	$ 0.60
Business acquisition, pro forma earnings per share, diluted (USD per share)			$ (0.09)	$ 0.59
Business acquisition, pro forma weighted average number of shares outstanding, basic (shares)			27,397,342	27,430,162
Business acquisition, pro forma weighted average number of shares, diluted (shares)			27,600,056	27,809,208
Acquisition-related Costs
Business Acquisition [Line Items]
Contract revenues			$ 0	$ 0
Costs of contract revenues			0	0
Gross profit			0	0
Selling, general and administrative expenses			0	0
(Loss) income from operations			0	0
(Loss) gain from sale of assets, net			0	0
Other income			0	0
Interest expense			0	0
Other (expense) income, net			0	0
(Loss) income before income taxes			0	0
Income tax (benefit) expense			0	0
Net (loss) income attributable to Orion common stockholders			$ 0	$ 0
Basic (loss) income per share (in dollars per share)			$ 0.00	$ 0.00
Diluted (loss) income per share (in dollars per share)			$ 0.00	$ 0.00
Basic (shares)			0	0
Diluted (shares)			0	0
Orion Marine Group, Inc.
Business Acquisition [Line Items]
Contract revenues			$ 257,614	$ 278,485
Costs of contract revenues			241,653	252,060
Gross profit			15,961	26,425
Selling, general and administrative expenses			27,550	23,953
(Loss) income from operations			(11,589)	2,472
(Loss) gain from sale of assets, net			(2,062)	165
Other income			1,253	467
Interest expense			(1,433)	(523)
Interest income			30	12
Other (expense) income, net			(2,212)	121
(Loss) income before income taxes			(13,801)	2,593
Income tax (benefit) expense			(2,945)	1,006
Net (loss) income attributable to Orion common stockholders			$ (10,856)	$ 1,587
Basic (loss) income per share (in dollars per share)			$ (0.40)	$ 0.06
Diluted (loss) income per share (in dollars per share)			$ (0.40)	$ 0.06
Basic (shares)			27,397,342	27,430,162
Diluted (shares)			27,397,342	27,809,208
TAS Commercial Concrete
Business Acquisition [Line Items]
Contract revenues			$ 183,032	$ 170,542
Costs of contract revenues			152,867	144,249
Gross profit			30,165	26,293
Selling, general and administrative expenses			16,772	12,309
(Loss) income from operations			13,393	13,984
(Loss) gain from sale of assets, net			547	29
Other income			727	737
Interest expense			(459)	(253)
Interest income			0	276
Other (expense) income, net			815	789
(Loss) income before income taxes			14,208	14,773
Income tax (benefit) expense			0	0
Net (loss) income attributable to Orion common stockholders			$ 14,208	$ 14,773
Basic (loss) income per share (in dollars per share)			$ 0.00	$ 0.00
Diluted (loss) income per share (in dollars per share)			$ 0.00	$ 0.00
Basic (shares)			0	0
Diluted (shares)			0	0
Consolidated Entities
Business Acquisition [Line Items]
Contract revenues			$ 440,646	$ 449,027
Costs of contract revenues			394,520	396,309
Gross profit			46,126	52,718
Selling, general and administrative expenses			44,322	36,262
(Loss) income from operations			1,804	16,456
(Loss) gain from sale of assets, net			(1,515)	194
Other income			1,980	1,204
Interest expense			(1,892)	(776)
Interest income			30	288
Other (expense) income, net			(1,397)	910
(Loss) income before income taxes			407	17,366
Income tax (benefit) expense			(2,945)	1,006
Net (loss) income attributable to Orion common stockholders			$ (2,538)	$ 16,360
Basic (loss) income per share (in dollars per share)			$ (0.09)	$ 0.60
Diluted (loss) income per share (in dollars per share)			$ (0.09)	$ 0.59
Basic (shares)			27,397,342	27,430,162
Diluted (shares)			27,600,056	27,809,208