Note 18 - Quarterly Financial Information - Quarterly Financial Information (Unaudited) (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended	12 Months Ended
Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Revenues	$ 168,345	$ 205,629	$ 189,582	$ 126,567	$ 152,488	$ 176,000	$ 177,425	$ 117,682	$ 690,123	$ 623,595	$ 672,230
Gross profit	6,903	17,032	16,089	3,830	12,220	14,458	9,111	(6,836)	43,854	28,953	32,421
Income (loss) before income taxes and earnings attributable to noncontrolling interests	(5,754)	3,196	2,570	(7,336)	(841)	1,326	(967)	(16,697)	(7,324)	(17,179)
Net income (loss) attributable to Sterling common stockholders	$ (6,348)	$ 2,415	$ 2,023	$ (7,328)	$ (19,898)	$ 256	$ (2,542)	$ (16,992)	$ (9,238)	$ (39,176)	$ (9,781)
Net income (loss) per share attributable to Sterling common stockholders:
Basic and diluted (in dollars per share)	$ (0.25)	$ 0.10	$ 0.09	$ (0.37)	$ (1.01)	$ 0.01	$ (0.13)	$ (0.90)	$ (0.40)	$ (2.02)	$ (0.54)
Revenues	$ 168,345	$ 205,629	$ 189,582	$ 126,567	$ 152,488	$ 176,000	$ 177,425	$ 117,682	$ 690,123	$ 623,595	$ 672,230
Gross profit	6,903	17,032	16,089	3,830	12,220	14,458	9,111	(6,836)	43,854	28,953	32,421
Income (loss) before income taxes and earnings attributable to noncontrolling interests	(5,754)	3,196	2,570	(7,336)	(841)	1,326	(967)	(16,697)	(7,324)	(17,179)
Net income (loss) attributable to Sterling common stockholders	$ (6,348)	$ 2,415	$ 2,023	$ (7,328)	$ (19,898)	$ 256	$ (2,542)	$ (16,992)	$ (9,238)	$ (39,176)	$ (9,781)

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- Definition

The amount of net income or loss for the period per each share in instances when basic and diluted earnings per share are the same amount and reported as a single line item on the face of the financial statements. Basic earnings per share is the amount of net income or loss for the period per each share of common stock or unit outstanding during the reporting period. Diluted earnings per share includes the amount of net income or loss for the period available to each share of common stock or common unit outstanding during the reporting period and to each share or unit that would have been outstanding assuming the issuance of common shares or units for all dilutive potential common shares or units outstanding during the reporting period.

+ References

No definition available.

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- Definition

Aggregate revenue less cost of goods and services sold or operating expenses directly attributable to the revenue generation activity.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 225
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03.1,2)
-URI http://asc.fasb.org/extlink&oid=63488584&loc=d3e20235-122688

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Amount of income (loss) from continuing operations before deduction of income tax expense (benefit) and income (loss) attributable to noncontrolling interest, and addition of income (loss) from equity method investments.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 235
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08.(h)(1)(i))
-URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e23780-122690

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- Definition

Net income after adjustments for dividends on preferred stock (declared in the period) and/or cumulative preferred stock (accumulated for the period).

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 260
-SubTopic 10
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Amount of revenue recognized from goods sold, services rendered, insurance premiums, or other activities that constitute an earning process. Includes, but is not limited to, investment and interest income before deduction of interest expense when recognized as a component of revenue, and sales and trading gain (loss).

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 225
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03.1)
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