Employee Benefit Plans - Additional Information (Details) - USD ($)		12 Months Ended
Dec. 31, 2024	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Percent of employees covered by collective bargaining agreements	32.00%
Contributions		$ 183,756,000	$ 149,764,000	$ 167,399,000
Percentage of contribution by employer of each employee's contribution up to 3%		100.00%
Percentage of contribution by employer of each employee who contributes between 3% and 6%		50.00%
Contributions to Quanta 401(k) Plan		$ 93,900,000	75,900,000	61,700,000
Contributions to the deferred compensation plans		2,300,000	1,800,000	1,500,000
Discretionary contributions		0	0	0
Deferred compensation obligations included in other long-term liabilities	$ 110,200,000	$ 110,200,000	$ 88,900,000
Deferred compensation arrangement with individual, common stock reserved for future issuance (in shares)	154,991	154,991	174,079
Investments in company-owned life insurance policies	$ 102,700,000	$ 102,700,000	$ 83,400,000
Minimum
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Percentage of employee contribution		3.00%
Maximum
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Percentage of employee contribution		6.00%
Multiemployer Defined Contribution and Other Benefit Plans
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Contributions		$ 282,500,000	$ 254,700,000	$ 234,300,000

Defined Contribution Plan, Employer Matching Contribution, Percent of Match By Employer Up To Specific Percentage

No definition available.

Name:	pwr_DefinedContributionPlanEmployerMatchingContributionPercentOfMatchByEmployerUpToSpecificPercentage
Namespace Prefix:	pwr_
Data Type:	dtr-types1:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Defined Contribution Plan, Employer Matching Contribution, Percent of Match By Employer Of Each Employee Who Contributes To Plan

+ References

No definition available.

+ Details

Name:	pwr_DefinedContributionPlanEmployerMatchingContributionPercentofMatchByEmployerOfEachEmployeeWhoContributesToPlan
Namespace Prefix:	pwr_
Data Type:	dtr-types1:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Number of common shares reserved for future issuance related to deferred compensation arrangements with individuals.

+ References

No definition available.

+ Details

Name:	us-gaap_DeferredCompensationArrangementWithIndividualCommonStockReservedForFutureIssuance
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant

- Definition

Amount of contributions made by employer into fund established for purposes of making future disbursement to individual in accordance with deferred compensation arrangement.

+ References

No definition available.

+ Details

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

- Definition

Aggregate carrying value as of the balance sheet date of the liabilities for all deferred compensation arrangements payable beyond one year (or the operating cycle, if longer).

+ References

No definition available.

+ Details

Name:	us-gaap_DeferredCompensationLiabilityClassifiedNoncurrent
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

+ Details

Name:	us-gaap_DefinedBenefitPlansAndOtherPostretirementBenefitPlansTableTextBlockLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount of cost for defined contribution plan.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 715
-SubTopic 70
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480794/715-70-50-1

+ Details

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

- Definition

Amount of discretionary contributions made by an employer to a defined contribution plan.

+ References

No definition available.

+ Details

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

- Definition

Percentage of employees' gross pay for which the employer contributes a matching contribution to a defined contribution plan.

+ References

No definition available.

+ Details

Name:	us-gaap_DefinedContributionPlanEmployerMatchingContributionPercent
Namespace Prefix:	us-gaap_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

This item represents the amount that could be realized under a life insurance contract or contracts owned by the Entity as of the date of the statement of financial position. Such Entity-owned life insurance policies are commonly known as corporate-owned life insurance (COLI) or bank-owned life insurance (BOLI).

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 210
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(12))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480566/210-10-S99-1

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 325
-SubTopic 30
-Name Accounting Standards Codification
-Section 25
-Paragraph 1
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481612/325-30-25-1

+ Details

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

- Definition

Amount of cost for employer contribution to multiemployer plan. Multiemployer plan includes, but is not limited to, pension plan determined to be individually significant and insignificant and other postretirement benefit plan.

+ References

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Topic 715
-SubTopic 80
-Name Accounting Standards Codification
-Section 55
-Paragraph 8
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480547/715-80-55-8

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 715
-SubTopic 80
-Name Accounting Standards Codification
-Section 35
-Paragraph 1
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480606/715-80-35-1

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 715
-SubTopic 80
-Name Accounting Standards Codification
-Section 50
-Paragraph 11
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480576/715-80-50-11

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Topic 715
-SubTopic 80
-Name Accounting Standards Codification
-Section 50
-Paragraph 9
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480576/715-80-50-9

+ Details

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

- Definition

Percentage of entity's employees covered by collective-bargaining arrangement (CBA) to all participants in multiemployer pension plan determined to be individually significant.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 715
-SubTopic 80
-Name Accounting Standards Codification
-Section 50
-Paragraph 5
-Subparagraph (d)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480576/715-80-50-5

+ Details

Name:	us-gaap_MultiemployerPlanPensionSignificantEmployeesCoveredByCollectiveBargainingArrangementToAllParticipantsPercentage
Namespace Prefix:	us-gaap_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

- Details

Name:	srt_RangeAxis=srt_MinimumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_RangeAxis=srt_MaximumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RetirementPlanNameAxis=pwr_MultiemployerDefinedContributionPlansAndOtherBenefitPlansMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: