Aggregate business acquisition consideration of acquired entity cash paid and liabilities incurred during period.

No definition available.

Name:	pwr_AggregateBusinessAcquisitionConsiderationOfAcquiredEntityCashPaidAndLiabilitiesIncurred
Namespace Prefix:	pwr_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

The number of businesses acquired by the entity during the period.

+ References

No definition available.

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Details

Name:	us-gaap_SubsequentEventLineItems
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Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Number of shares that have been repurchased during the period and are being held in treasury.

+ References

+ Details

Name:	us-gaap_TreasuryStockSharesAcquired
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

- Definition

Equity impact of the cost of common and preferred stock that were repurchased during the period. Recorded using the cost method.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 04

-Article 3

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 505

-SubTopic 10

-Section 50

-Paragraph 2

-URI http://asc.fasb.org/extlink&oid=6928386&loc=d3e21463-112644

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 505

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.3-04)

-URI http://asc.fasb.org/extlink&oid=27012166&loc=d3e187085-122770

Reference 4: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 505

-SubTopic 30

-Section 45

-Paragraph 1

-URI http://asc.fasb.org/extlink&oid=6405813&loc=d3e23239-112655

+ Details

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

- Details

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

Subsequent Event - Additional Information (Detail) (USD $) In Thousands, except Share data, unless otherwise specified	6 Months Ended	12 Months Ended			3 Months Ended
	Jun. 30, 2012 Entity	Dec. 31, 2014 Entity	Dec. 31, 2013 Entity	Dec. 31, 2012 Entity	Mar. 31, 2015 Entity
Subsequent Event [Line Items]
Number of business acquisitions	4us-gaap_NumberOfBusinessesAcquired	9us-gaap_NumberOfBusinessesAcquired	6us-gaap_NumberOfBusinessesAcquired	4us-gaap_NumberOfBusinessesAcquired
Cash paid for acquisitions		$ 284,300	$ 341,100
Common stock repurchases		93,482
Scenario Forecast [Member]
Subsequent Event [Line Items]
Number of business acquisitions					3
Cash paid for acquisitions					36,300
Common stock repurchases, shares					6,700,000
Common stock repurchases					$ 182,000