XML 29 R32.htm IDEA: XBRL DOCUMENT v2.4.1.9
Concentration of Risk and Enterprise Wide Disclosures (Details) (USD $)
In Thousands, unless otherwise specified
 3 Months Ended 12 Months Ended
Mar. 31, 2015
Mar. 31, 2014
Dec. 31, 2014
Concentration Risk [Line Items]      
Contract revenues $ 81,455us-gaap_ContractsRevenue $ 81,258us-gaap_ContractsRevenue  
Contract revenues      
Concentration Risk [Line Items]      
Contract revenues 81,455us-gaap_ContractsRevenue
/ us-gaap_ConcentrationRiskByBenchmarkAxis
= us-gaap_SalesRevenueServicesNetMember		    
Customer concentration risk | Trade and contract retainage receivables      
Concentration Risk [Line Items]      
Trade and retainage receivables 42,398orn_TradeAccountsReceivableAndContractReceivableRetainageNet
/ us-gaap_ConcentrationRiskByBenchmarkAxis
= orn_TradeAndContractRetainageReceivablesMember
/ us-gaap_ConcentrationRiskByTypeAxis
= us-gaap_CustomerConcentrationRiskMember		   52,788orn_TradeAccountsReceivableAndContractReceivableRetainageNet
/ us-gaap_ConcentrationRiskByBenchmarkAxis
= orn_TradeAndContractRetainageReceivablesMember
/ us-gaap_ConcentrationRiskByTypeAxis
= us-gaap_CustomerConcentrationRiskMember
Concentration risk, percentage 100.00%us-gaap_ConcentrationRiskPercentage1
/ us-gaap_ConcentrationRiskByBenchmarkAxis
= orn_TradeAndContractRetainageReceivablesMember
/ us-gaap_ConcentrationRiskByTypeAxis
= us-gaap_CustomerConcentrationRiskMember		   100.00%us-gaap_ConcentrationRiskPercentage1
/ us-gaap_ConcentrationRiskByBenchmarkAxis
= orn_TradeAndContractRetainageReceivablesMember
/ us-gaap_ConcentrationRiskByTypeAxis
= us-gaap_CustomerConcentrationRiskMember
Customer concentration risk | Contract revenues      
Concentration Risk [Line Items]      
Contract revenues   81,258us-gaap_ContractsRevenue
/ us-gaap_ConcentrationRiskByBenchmarkAxis
= us-gaap_SalesRevenueServicesNetMember
/ us-gaap_ConcentrationRiskByTypeAxis
= us-gaap_CustomerConcentrationRiskMember		  
Concentration risk, percentage 100.00%us-gaap_ConcentrationRiskPercentage1
/ us-gaap_ConcentrationRiskByBenchmarkAxis
= us-gaap_SalesRevenueServicesNetMember
/ us-gaap_ConcentrationRiskByTypeAxis
= us-gaap_CustomerConcentrationRiskMember		 100.00%us-gaap_ConcentrationRiskPercentage1
/ us-gaap_ConcentrationRiskByBenchmarkAxis
= us-gaap_SalesRevenueServicesNetMember
/ us-gaap_ConcentrationRiskByTypeAxis
= us-gaap_CustomerConcentrationRiskMember		  
Customer concentration risk | Federal Government | Trade and contract retainage receivables      
Concentration Risk [Line Items]      
Trade and retainage receivables 4,376orn_TradeAccountsReceivableAndContractReceivableRetainageNet
/ us-gaap_ConcentrationRiskByBenchmarkAxis
= orn_TradeAndContractRetainageReceivablesMember
/ us-gaap_ConcentrationRiskByTypeAxis
= us-gaap_CustomerConcentrationRiskMember
/ orn_CustomerByTypeAxis
= orn_CustomerTypeFederalMember		   4,607orn_TradeAccountsReceivableAndContractReceivableRetainageNet
/ us-gaap_ConcentrationRiskByBenchmarkAxis
= orn_TradeAndContractRetainageReceivablesMember
/ us-gaap_ConcentrationRiskByTypeAxis
= us-gaap_CustomerConcentrationRiskMember
/ orn_CustomerByTypeAxis
= orn_CustomerTypeFederalMember
Concentration risk, percentage 10.00%us-gaap_ConcentrationRiskPercentage1
/ us-gaap_ConcentrationRiskByBenchmarkAxis
= orn_TradeAndContractRetainageReceivablesMember
/ us-gaap_ConcentrationRiskByTypeAxis
= us-gaap_CustomerConcentrationRiskMember
/ orn_CustomerByTypeAxis
= orn_CustomerTypeFederalMember		   9.00%us-gaap_ConcentrationRiskPercentage1
/ us-gaap_ConcentrationRiskByBenchmarkAxis
= orn_TradeAndContractRetainageReceivablesMember
/ us-gaap_ConcentrationRiskByTypeAxis
= us-gaap_CustomerConcentrationRiskMember
/ orn_CustomerByTypeAxis
= orn_CustomerTypeFederalMember
Customer concentration risk | Federal Government | Contract revenues      
Concentration Risk [Line Items]      
Contract revenues 12,312us-gaap_ContractsRevenue
/ us-gaap_ConcentrationRiskByBenchmarkAxis
= us-gaap_SalesRevenueServicesNetMember
/ us-gaap_ConcentrationRiskByTypeAxis
= us-gaap_CustomerConcentrationRiskMember
/ orn_CustomerByTypeAxis
= orn_CustomerTypeFederalMember		 11,897us-gaap_ContractsRevenue
/ us-gaap_ConcentrationRiskByBenchmarkAxis
= us-gaap_SalesRevenueServicesNetMember
/ us-gaap_ConcentrationRiskByTypeAxis
= us-gaap_CustomerConcentrationRiskMember
/ orn_CustomerByTypeAxis
= orn_CustomerTypeFederalMember		  
Concentration risk, percentage 15.00%us-gaap_ConcentrationRiskPercentage1
/ us-gaap_ConcentrationRiskByBenchmarkAxis
= us-gaap_SalesRevenueServicesNetMember
/ us-gaap_ConcentrationRiskByTypeAxis
= us-gaap_CustomerConcentrationRiskMember
/ orn_CustomerByTypeAxis
= orn_CustomerTypeFederalMember		 15.00%us-gaap_ConcentrationRiskPercentage1
/ us-gaap_ConcentrationRiskByBenchmarkAxis
= us-gaap_SalesRevenueServicesNetMember
/ us-gaap_ConcentrationRiskByTypeAxis
= us-gaap_CustomerConcentrationRiskMember
/ orn_CustomerByTypeAxis
= orn_CustomerTypeFederalMember		  
Customer concentration risk | State Governments | Trade and contract retainage receivables      
Concentration Risk [Line Items]      
Trade and retainage receivables 1,346orn_TradeAccountsReceivableAndContractReceivableRetainageNet
/ us-gaap_ConcentrationRiskByBenchmarkAxis
= orn_TradeAndContractRetainageReceivablesMember
/ us-gaap_ConcentrationRiskByTypeAxis
= us-gaap_CustomerConcentrationRiskMember
/ orn_CustomerByTypeAxis
= orn_CustomerTypeStateMember		   476orn_TradeAccountsReceivableAndContractReceivableRetainageNet
/ us-gaap_ConcentrationRiskByBenchmarkAxis
= orn_TradeAndContractRetainageReceivablesMember
/ us-gaap_ConcentrationRiskByTypeAxis
= us-gaap_CustomerConcentrationRiskMember
/ orn_CustomerByTypeAxis
= orn_CustomerTypeStateMember
Concentration risk, percentage 3.00%us-gaap_ConcentrationRiskPercentage1
/ us-gaap_ConcentrationRiskByBenchmarkAxis
= orn_TradeAndContractRetainageReceivablesMember
/ us-gaap_ConcentrationRiskByTypeAxis
= us-gaap_CustomerConcentrationRiskMember
/ orn_CustomerByTypeAxis
= orn_CustomerTypeStateMember		   1.00%us-gaap_ConcentrationRiskPercentage1
/ us-gaap_ConcentrationRiskByBenchmarkAxis
= orn_TradeAndContractRetainageReceivablesMember
/ us-gaap_ConcentrationRiskByTypeAxis
= us-gaap_CustomerConcentrationRiskMember
/ orn_CustomerByTypeAxis
= orn_CustomerTypeStateMember
Customer concentration risk | State Governments | Contract revenues      
Concentration Risk [Line Items]      
Contract revenues 9,631us-gaap_ContractsRevenue
/ us-gaap_ConcentrationRiskByBenchmarkAxis
= us-gaap_SalesRevenueServicesNetMember
/ us-gaap_ConcentrationRiskByTypeAxis
= us-gaap_CustomerConcentrationRiskMember
/ orn_CustomerByTypeAxis
= orn_CustomerTypeStateMember		 6,911us-gaap_ContractsRevenue
/ us-gaap_ConcentrationRiskByBenchmarkAxis
= us-gaap_SalesRevenueServicesNetMember
/ us-gaap_ConcentrationRiskByTypeAxis
= us-gaap_CustomerConcentrationRiskMember
/ orn_CustomerByTypeAxis
= orn_CustomerTypeStateMember		  
Concentration risk, percentage 12.00%us-gaap_ConcentrationRiskPercentage1
/ us-gaap_ConcentrationRiskByBenchmarkAxis
= us-gaap_SalesRevenueServicesNetMember
/ us-gaap_ConcentrationRiskByTypeAxis
= us-gaap_CustomerConcentrationRiskMember
/ orn_CustomerByTypeAxis
= orn_CustomerTypeStateMember		 8.00%us-gaap_ConcentrationRiskPercentage1
/ us-gaap_ConcentrationRiskByBenchmarkAxis
= us-gaap_SalesRevenueServicesNetMember
/ us-gaap_ConcentrationRiskByTypeAxis
= us-gaap_CustomerConcentrationRiskMember
/ orn_CustomerByTypeAxis
= orn_CustomerTypeStateMember		  
Customer concentration risk | Local Governments | Trade and contract retainage receivables      
Concentration Risk [Line Items]      
Trade and retainage receivables 13,517orn_TradeAccountsReceivableAndContractReceivableRetainageNet
/ us-gaap_ConcentrationRiskByBenchmarkAxis
= orn_TradeAndContractRetainageReceivablesMember
/ us-gaap_ConcentrationRiskByTypeAxis
= us-gaap_CustomerConcentrationRiskMember
/ orn_CustomerByTypeAxis
= orn_CustomerTypeLocalMember		   13,927orn_TradeAccountsReceivableAndContractReceivableRetainageNet
/ us-gaap_ConcentrationRiskByBenchmarkAxis
= orn_TradeAndContractRetainageReceivablesMember
/ us-gaap_ConcentrationRiskByTypeAxis
= us-gaap_CustomerConcentrationRiskMember
/ orn_CustomerByTypeAxis
= orn_CustomerTypeLocalMember
Concentration risk, percentage 32.00%us-gaap_ConcentrationRiskPercentage1
/ us-gaap_ConcentrationRiskByBenchmarkAxis
= orn_TradeAndContractRetainageReceivablesMember
/ us-gaap_ConcentrationRiskByTypeAxis
= us-gaap_CustomerConcentrationRiskMember
/ orn_CustomerByTypeAxis
= orn_CustomerTypeLocalMember		   26.00%us-gaap_ConcentrationRiskPercentage1
/ us-gaap_ConcentrationRiskByBenchmarkAxis
= orn_TradeAndContractRetainageReceivablesMember
/ us-gaap_ConcentrationRiskByTypeAxis
= us-gaap_CustomerConcentrationRiskMember
/ orn_CustomerByTypeAxis
= orn_CustomerTypeLocalMember
Customer concentration risk | Local Governments | Contract revenues      
Concentration Risk [Line Items]      
Contract revenues 21,292us-gaap_ContractsRevenue
/ us-gaap_ConcentrationRiskByBenchmarkAxis
= us-gaap_SalesRevenueServicesNetMember
/ us-gaap_ConcentrationRiskByTypeAxis
= us-gaap_CustomerConcentrationRiskMember
/ orn_CustomerByTypeAxis
= orn_CustomerTypeLocalMember		 13,505us-gaap_ContractsRevenue
/ us-gaap_ConcentrationRiskByBenchmarkAxis
= us-gaap_SalesRevenueServicesNetMember
/ us-gaap_ConcentrationRiskByTypeAxis
= us-gaap_CustomerConcentrationRiskMember
/ orn_CustomerByTypeAxis
= orn_CustomerTypeLocalMember		  
Concentration risk, percentage 26.00%us-gaap_ConcentrationRiskPercentage1
/ us-gaap_ConcentrationRiskByBenchmarkAxis
= us-gaap_SalesRevenueServicesNetMember
/ us-gaap_ConcentrationRiskByTypeAxis
= us-gaap_CustomerConcentrationRiskMember
/ orn_CustomerByTypeAxis
= orn_CustomerTypeLocalMember		 17.00%us-gaap_ConcentrationRiskPercentage1
/ us-gaap_ConcentrationRiskByBenchmarkAxis
= us-gaap_SalesRevenueServicesNetMember
/ us-gaap_ConcentrationRiskByTypeAxis
= us-gaap_CustomerConcentrationRiskMember
/ orn_CustomerByTypeAxis
= orn_CustomerTypeLocalMember		  
Customer concentration risk | Private Companies | Trade and contract retainage receivables      
Concentration Risk [Line Items]      
Trade and retainage receivables 23,159orn_TradeAccountsReceivableAndContractReceivableRetainageNet
/ us-gaap_ConcentrationRiskByBenchmarkAxis
= orn_TradeAndContractRetainageReceivablesMember
/ us-gaap_ConcentrationRiskByTypeAxis
= us-gaap_CustomerConcentrationRiskMember
/ orn_CustomerByTypeAxis
= orn_CustomerTypePrivateMember		   33,778orn_TradeAccountsReceivableAndContractReceivableRetainageNet
/ us-gaap_ConcentrationRiskByBenchmarkAxis
= orn_TradeAndContractRetainageReceivablesMember
/ us-gaap_ConcentrationRiskByTypeAxis
= us-gaap_CustomerConcentrationRiskMember
/ orn_CustomerByTypeAxis
= orn_CustomerTypePrivateMember
Concentration risk, percentage 55.00%us-gaap_ConcentrationRiskPercentage1
/ us-gaap_ConcentrationRiskByBenchmarkAxis
= orn_TradeAndContractRetainageReceivablesMember
/ us-gaap_ConcentrationRiskByTypeAxis
= us-gaap_CustomerConcentrationRiskMember
/ orn_CustomerByTypeAxis
= orn_CustomerTypePrivateMember		   64.00%us-gaap_ConcentrationRiskPercentage1
/ us-gaap_ConcentrationRiskByBenchmarkAxis
= orn_TradeAndContractRetainageReceivablesMember
/ us-gaap_ConcentrationRiskByTypeAxis
= us-gaap_CustomerConcentrationRiskMember
/ orn_CustomerByTypeAxis
= orn_CustomerTypePrivateMember
Customer concentration risk | Private Companies | Contract revenues      
Concentration Risk [Line Items]      
Contract revenues $ 38,220us-gaap_ContractsRevenue
/ us-gaap_ConcentrationRiskByBenchmarkAxis
= us-gaap_SalesRevenueServicesNetMember
/ us-gaap_ConcentrationRiskByTypeAxis
= us-gaap_CustomerConcentrationRiskMember
/ orn_CustomerByTypeAxis
= orn_CustomerTypePrivateMember		 $ 48,945us-gaap_ContractsRevenue
/ us-gaap_ConcentrationRiskByBenchmarkAxis
= us-gaap_SalesRevenueServicesNetMember
/ us-gaap_ConcentrationRiskByTypeAxis
= us-gaap_CustomerConcentrationRiskMember
/ orn_CustomerByTypeAxis
= orn_CustomerTypePrivateMember		  
Concentration risk, percentage 47.00%us-gaap_ConcentrationRiskPercentage1
/ us-gaap_ConcentrationRiskByBenchmarkAxis
= us-gaap_SalesRevenueServicesNetMember
/ us-gaap_ConcentrationRiskByTypeAxis
= us-gaap_CustomerConcentrationRiskMember
/ orn_CustomerByTypeAxis
= orn_CustomerTypePrivateMember		 60.00%us-gaap_ConcentrationRiskPercentage1
/ us-gaap_ConcentrationRiskByBenchmarkAxis
= us-gaap_SalesRevenueServicesNetMember
/ us-gaap_ConcentrationRiskByTypeAxis
= us-gaap_CustomerConcentrationRiskMember
/ orn_CustomerByTypeAxis
= orn_CustomerTypePrivateMember