Quarterly report pursuant to Section 13 or 15(d)

Segment Information - Summarized Financial Information (Detail)

v2.4.1.9
Segment Information - Summarized Financial Information (Detail) (USD $)
In Thousands, unless otherwise specified
3 Months Ended
Mar. 31, 2015
Mar. 31, 2014
Segment Reporting Information [Line Items]    
Revenues $ 1,886,956us-gaap_SalesRevenueServicesNet $ 1,762,574us-gaap_SalesRevenueServicesNet
Operating income (loss) 93,717us-gaap_OperatingIncomeLoss 90,495us-gaap_OperatingIncomeLoss
Depreciation 44,074us-gaap_Depreciation 36,865us-gaap_Depreciation
Electric Power Infrastructure [Member]    
Segment Reporting Information [Line Items]    
Revenues 1,225,743us-gaap_SalesRevenueServicesNet
/ us-gaap_StatementBusinessSegmentsAxis
= pwr_ElectricPowerInfrastructureMember
1,278,168us-gaap_SalesRevenueServicesNet
/ us-gaap_StatementBusinessSegmentsAxis
= pwr_ElectricPowerInfrastructureMember
Operating income (loss) 107,932us-gaap_OperatingIncomeLoss
/ us-gaap_StatementBusinessSegmentsAxis
= pwr_ElectricPowerInfrastructureMember
144,412us-gaap_OperatingIncomeLoss
/ us-gaap_StatementBusinessSegmentsAxis
= pwr_ElectricPowerInfrastructureMember
Depreciation 20,527us-gaap_Depreciation
/ us-gaap_StatementBusinessSegmentsAxis
= pwr_ElectricPowerInfrastructureMember
17,564us-gaap_Depreciation
/ us-gaap_StatementBusinessSegmentsAxis
= pwr_ElectricPowerInfrastructureMember
Oil and Gas Infrastructure Services [Member]    
Segment Reporting Information [Line Items]    
Revenues 621,094us-gaap_SalesRevenueServicesNet
/ us-gaap_StatementBusinessSegmentsAxis
= pwr_OilAndGasInfrastructureServicesMember
445,857us-gaap_SalesRevenueServicesNet
/ us-gaap_StatementBusinessSegmentsAxis
= pwr_OilAndGasInfrastructureServicesMember
Operating income (loss) 24,147us-gaap_OperatingIncomeLoss
/ us-gaap_StatementBusinessSegmentsAxis
= pwr_OilAndGasInfrastructureServicesMember
(21,172)us-gaap_OperatingIncomeLoss
/ us-gaap_StatementBusinessSegmentsAxis
= pwr_OilAndGasInfrastructureServicesMember
Depreciation 16,469us-gaap_Depreciation
/ us-gaap_StatementBusinessSegmentsAxis
= pwr_OilAndGasInfrastructureServicesMember
13,215us-gaap_Depreciation
/ us-gaap_StatementBusinessSegmentsAxis
= pwr_OilAndGasInfrastructureServicesMember
Fiber Optic Licensing and Other [Member]    
Segment Reporting Information [Line Items]    
Revenues 40,119us-gaap_SalesRevenueServicesNet
/ us-gaap_StatementBusinessSegmentsAxis
= pwr_FiberOpticLicensingAndOtherMember
38,549us-gaap_SalesRevenueServicesNet
/ us-gaap_StatementBusinessSegmentsAxis
= pwr_FiberOpticLicensingAndOtherMember
Operating income (loss) 11,532us-gaap_OperatingIncomeLoss
/ us-gaap_StatementBusinessSegmentsAxis
= pwr_FiberOpticLicensingAndOtherMember
12,109us-gaap_OperatingIncomeLoss
/ us-gaap_StatementBusinessSegmentsAxis
= pwr_FiberOpticLicensingAndOtherMember
Depreciation 5,066us-gaap_Depreciation
/ us-gaap_StatementBusinessSegmentsAxis
= pwr_FiberOpticLicensingAndOtherMember
4,318us-gaap_Depreciation
/ us-gaap_StatementBusinessSegmentsAxis
= pwr_FiberOpticLicensingAndOtherMember
Corporate and Non-Allocated Costs [Member]    
Segment Reporting Information [Line Items]    
Operating income (loss) (49,894)us-gaap_OperatingIncomeLoss
/ us-gaap_StatementBusinessSegmentsAxis
= pwr_CorporateAndNonAllocatedCostsMember
(44,854)us-gaap_OperatingIncomeLoss
/ us-gaap_StatementBusinessSegmentsAxis
= pwr_CorporateAndNonAllocatedCostsMember
Depreciation $ 2,012us-gaap_Depreciation
/ us-gaap_StatementBusinessSegmentsAxis
= pwr_CorporateAndNonAllocatedCostsMember
$ 1,768us-gaap_Depreciation
/ us-gaap_StatementBusinessSegmentsAxis
= pwr_CorporateAndNonAllocatedCostsMember