Represents a contract value.

No definition available.

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Namespace Prefix:	pwr_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Percent change in contract estimates impact on operating results is less than this percentage.

+ References

No definition available.

+ Details

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Namespace Prefix:	pwr_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Revenue recognition.

+ References

No definition available.

+ Details

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Period Type:	duration

- Definition

Losses recognized in the current period on contracts which are expected to generate losses, which are probable and can be reasonably estimated, in a future period.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 450
-SubTopic 20
-Section 50
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=25496072&loc=d3e14326-108349

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 225
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03.2)
-URI http://asc.fasb.org/extlink&oid=63488584&loc=d3e20235-122688

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Aggregate revenue during the period from services rendered in the normal course of business, after deducting allowances and discounts.

+ 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(d))
-URI http://asc.fasb.org/extlink&oid=63488584&loc=d3e20235-122688

+ Details

Name:	us-gaap_SalesRevenueServicesNet
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

The amount of costs incurred on unapproved change orders when it is probable that the cost will be recovered through a change in the contract price.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(3)(c)(3))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 910
-SubTopic 310
-Section 50
-Paragraph 1
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=68065756&loc=d3e49324-109356

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 910
-SubTopic 340
-Section 50
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=68053980&loc=d3e50000-109363

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Details

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Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_TypeOfArrangementAxis=pwr_AlaskaPowerPlantConstructionProjectMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_UnusualRiskOrUncertaintyByNatureAxis=pwr_RevenueRecognizedForLossesMember
Namespace Prefix:
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Summary of Significant Accounting Policies (Revenue Recognition) - Additional Information (Detail) - USD ($)	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
Revenue Recognition [Line Items]
Revenues	$ 2,102,966,000	$ 2,042,186,000	$ 1,792,430,000	$ 1,713,737,000	$ 1,899,272,000	$ 1,939,438,000	$ 1,872,340,000	$ 1,861,386,000	$ 7,651,319,000	$ 7,572,436,000	$ 7,747,229,000
Change orders and/or claims	137,800,000				$ 137,200,000				$ 137,800,000	$ 137,200,000
Maximum [Member]
Revenue Recognition [Line Items]
Percent change in contract estimates impact on operating results is less than this percentage									5.00%	5.00%	5.00%
Alaska Power Plant Construction Project [Member]
Revenue Recognition [Line Items]
Losses on Contracts									$ 54,800,000	$ 44,900,000
Contract value of project	$ 202,000,000								202,000,000
Revenue Recognized For Losses Member \| Alaska Power Plant Construction Project [Member]
Revenue Recognition [Line Items]
Revenues									$ 0