XML 51 R41.htm IDEA: XBRL DOCUMENT
v3.7.0.1

Note 5 - Construction Joint Ventures (Details Textual) $ in Millions | Jun. 30, 2017 USD ($)
--- | ---
Construction Backlog Attributable to Project Performed by Joint Ventures | $ 39
Granite Construction Corporation [Member] |
Equity Method Investment, Ownership Percentage | 50.00%

X
- Definition Amount of construction backlog attributable to project performed by joint ventures. + References No definition available. + Details
Name: | strl_ConstructionBacklogAttributableToProjectPerformedByJointVentures
Namespace Prefix: | strl_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition The percentage of ownership of common stock or equity participation in the investee accounted for under the equity method of accounting. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 323 -SubTopic 10 -Section 50 -Paragraph 3 -Subparagraph (a)(1) -URI http://asc.fasb.org/extlink&oid=66011266&loc=d3e33918-111571 + Details
Name: | us-gaap_EquityMethodInvestmentOwnershipPercentage
Namespace Prefix: | us-gaap_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | instant

X
- Details
Name: | us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis=strl_GraniteConstructionCorporationMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |