Refers to the cash payment related to the change of control payments in association with the business acquisition.

No definition available.

Name:	trgp_BusinessAcquisitionCashPaymentRelatedToChangeOfControlPayments
Namespace Prefix:	trgp_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Debt instrument maturity month year.

+ References

No definition available.

+ Details

Name:	trgp_DebtInstrumentMaturityMonthYear
Namespace Prefix:	trgp_
Data Type:	xbrli:gYearMonthItemType
Balance Type:	na
Period Type:	duration

- Definition

The additional commitment increase under the credit facility available upon request.

+ References

No definition available.

+ Details

Name:	trgp_LineOfCreditAdditionalCommitmentIncreaseAvailableUponRequest
Namespace Prefix:	trgp_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Financial covenant which sets forth the maximum ratio of consolidated funded indebtedness to consolidated adjusted EBITDA (consolidated leverage ratio).

+ References

No definition available.

+ Details

Name:	trgp_LineOfCreditMaximumConsolidatedLeverageRatio
Namespace Prefix:	trgp_
Data Type:	xbrli:pureItemType
Balance Type:	na
Period Type:	duration

- Definition

Financial covenant which sets forth the minimum ratio of consolidated EBITDA to consolidated interest expense.

+ References

No definition available.

+ Details

Name:	trgp_LineOfCreditMinimumRatioOfConsolidatedEbitdaToConsolidatedInterestExpense
Namespace Prefix:	trgp_
Data Type:	xbrli:pureItemType
Balance Type:	na
Period Type:	duration

- Definition

Percentage points added to the reference rate to compute the variable rate on the debt instrument.

+ References

No definition available.

+ Details

Name:	us-gaap_DebtInstrumentBasisSpreadOnVariableRate1
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Contractual interest rate for funds borrowed, under the debt agreement.

+ 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 210.5-02.22(a)(1))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

+ Details

Name:	us-gaap_DebtInstrumentInterestRateStatedPercentage
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
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_DebtInstrumentLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

The fee, expressed as a percentage of the line of credit facility, for the line of credit facility regardless of whether the facility has been used.

+ References

No definition available.

+ Details

Name:	us-gaap_LineOfCreditFacilityCommitmentFeePercentage
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Maximum borrowing capacity under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility.

+ 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 210.5-02.19(b),22(b))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

+ Details

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

- Definition

The cash outflow associated with the acquisition of business during the period. The cash portion only of the acquisition price.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Glossary Investing Activities
-URI http://asc.fasb.org/extlink&oid=6516133

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 13
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=66902209&loc=d3e3213-108585

+ Details

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

- Definition

Write-off of amounts previously capitalized as debt issuance cost in an extinguishment of debt.

+ 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 210.5-03.8)
-URI http://asc.fasb.org/extlink&oid=63488584&loc=d3e20235-122688

+ Details

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

- Details

Name:	us-gaap_BusinessAcquisitionAxis=trgp_AtlasPipelinePartnersLPAcquisitionMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_CreditFacilityAxis=us-gaap_RevolvingCreditFacilityMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	dei_LegalEntityAxis=trgp_TargaResourcesPartnersLpMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=trgp_TRPRevolverMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RangeAxis=us-gaap_MinimumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RangeAxis=us-gaap_MaximumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_VariableRateAxis=trgp_FederalFundsRateMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_VariableRateAxis=us-gaap_LondonInterbankOfferedRateLIBORMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_VariableRateAxis=us-gaap_BaseRateMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_VariableRateAxis=us-gaap_EurodollarMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=trgp_SecondAmendmentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_CreditFacilityAxis=us-gaap_LetterOfCreditMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Debt Obligations, Partnership's Revolving Credit Facility - Additional Information (Details) - USD ($)		1 Months Ended	3 Months Ended	12 Months Ended
	Feb. 27, 2015	Oct. 31, 2016	Dec. 31, 2016	Dec. 31, 2016	Dec. 31, 2015	Feb. 28, 2015
Debt Instrument [Line Items]
Write off debt issuance cost				$ 3,500,000	$ 100,000
Atlas Pipeline Partners [Member]
Debt Instrument [Line Items]
Cash payments related to change of control payments					28,800,000
Revolving Credit Facility [Member] \| Atlas Pipeline Partners [Member]
Debt Instrument [Line Items]
Cash payments related to acquisition	$ 701,400,000				$ 701,400,000
Targa Resources Partners LP [Member] \| TRP Revolver [Member]
Debt Instrument [Line Items]
Maximum consolidated leverage ratio				5.50
Minimum ratio of consolidated EBITDA to consolidated interest expense				2.25
Targa Resources Partners LP [Member] \| TRP Revolver [Member] \| Minimum [Member]
Debt Instrument [Line Items]
Commitment fee percentage				0.30%
Targa Resources Partners LP [Member] \| TRP Revolver [Member] \| Maximum [Member]
Debt Instrument [Line Items]
Commitment fee percentage				0.50%
Targa Resources Partners LP [Member] \| TRP Revolver [Member] \| Federal Funds Rate [Member]
Debt Instrument [Line Items]
Commitment fee percentage				0.50%
Targa Resources Partners LP [Member] \| TRP Revolver [Member] \| LIBOR [Member]
Debt Instrument [Line Items]
Debt instrument, basis spread on variable rate				1.00%
Targa Resources Partners LP [Member] \| TRP Revolver [Member] \| Base Rate [Member] \| Minimum [Member]
Debt Instrument [Line Items]
Debt instrument, basis spread on variable rate				0.75%
Targa Resources Partners LP [Member] \| TRP Revolver [Member] \| Base Rate [Member] \| Maximum [Member]
Debt Instrument [Line Items]
Debt instrument, basis spread on variable rate				1.75%
Targa Resources Partners LP [Member] \| TRP Revolver [Member] \| Eurodollar \| Minimum [Member]
Debt Instrument [Line Items]
Debt instrument, basis spread on variable rate				1.75%
Targa Resources Partners LP [Member] \| TRP Revolver [Member] \| Eurodollar \| Maximum [Member]
Debt Instrument [Line Items]
Debt instrument, basis spread on variable rate				2.75%
Targa Resources Partners LP [Member] \| Revolving Credit Facility [Member] \| Second Amendment [Member]
Debt Instrument [Line Items]
Maximum borrowing capacity		$ 1,600,000,000
Additional commitment increase available upon request		$ 500,000,000				$ 300,000,000
Debt maturity period		2020-10
Write off debt issuance cost			$ 900,000
Targa Resources Partners LP [Member] \| Letters of Credit [Member] \| TRP Revolver [Member] \| Minimum [Member]
Debt Instrument [Line Items]
Interest rate on fixed rate debt			1.75%	1.75%
Targa Resources Partners LP [Member] \| Letters of Credit [Member] \| TRP Revolver [Member] \| Maximum [Member]
Debt Instrument [Line Items]
Interest rate on fixed rate debt			2.75%	2.75%