Amount paid for premium on extinguishment of debt.

No definition available.

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Namespace Prefix:	trgp_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

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

+ References

No definition available.

+ Details

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Namespace Prefix:	trgp_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Write off of unamortized debt premium.

+ References

No definition available.

+ Details

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Namespace Prefix:	trgp_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
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

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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

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Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Date when the debt instrument is scheduled to be fully repaid, in CCYY-MM-DD format.

+ 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)(2))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

+ Details

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Data Type:	xbrli:dateItemType
Balance Type:	na
Period Type:	duration

- Definition

Difference between the fair value of payments made and the carrying amount of debt which is extinguished prior to maturity.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 50
-Section 40
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=49170532&loc=d3e12317-112629

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 28
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=66902209&loc=d3e3602-108585

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 50
-Section 40
-Paragraph 4
-URI http://asc.fasb.org/extlink&oid=49170532&loc=d3e12355-112629

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- Definition

Including the current and noncurrent portions, carrying value as of the balance sheet date of Notes with the highest claim on the assets of the issuer in case of bankruptcy or liquidation (with maturities initially due after one year or beyond the operating cycle if longer). Senior note holders are paid off in full before any payments are made to junior note holders.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-03.16(a))
-URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03.16)
-URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- 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

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

- Details

Name:	us-gaap_LongtermDebtTypeAxis=trgp_ConcurrentSeniorNotesTenderOffersMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=trgp_SeniorUnsecuredNotesDueJanuary2018Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=trgp_SeniorUnsecuredNotesDueOctober2020Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=trgp_SeniorUnsecuredNotesDueFebruary2021Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_LongtermDebtTypeAxis=trgp_SeniorNotesWithOffersTenderedMember
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Debt Obligations - Senior Notes Tender Offers - Additional Information (Details) - USD ($)	1 Months Ended	3 Months Ended	12 Months Ended
	Oct. 31, 2016	Dec. 31, 2016	Dec. 31, 2016	Dec. 31, 2015
Debt Instrument [Line Items]
Write off debt issuance cost			$ 3,500,000	$ 100,000
Concurrent Senior Notes Tender Offers [Member]
Debt Instrument [Line Items]
Aggregate principal amount outstanding	$ 1,000
Concurrent Senior Notes Tender Offers [Member] \| Senior Unsecured 5% Notes due January 2018 [Member]
Debt Instrument [Line Items]
Interest rate on fixed rate debt	5.00%
Maturity date	Jan. 15, 2018
Concurrent Senior Notes Tender Offers [Member] \| Senior Unsecured 6 5/8% Notes due October 2020 [Member]
Debt Instrument [Line Items]
Interest rate on fixed rate debt	6.625%
Maturity date	Oct. 01, 2020
Concurrent Senior Notes Tender Offers [Member] \| Senior Unsecured 6 7/8% Notes due February 2021 [Member]
Debt Instrument [Line Items]
Interest rate on fixed rate debt	6.875%
Maturity date	Feb. 01, 2021
Senior Notes with Offers Tendered [Member]
Debt Instrument [Line Items]
Aggregate principal amount outstanding		$ 383,800,000	383,800,000	1,522,100,000
Loss on extinguishment of debt		59,200,000
Premium Paid		41,800,000	41,800,000
Write off debt issuance cost		5,800,000
Write off of debt premiums		3,500,000
Write off of debt discount		15,100,000
Senior Notes with Offers Tendered [Member] \| Senior Unsecured 5% Notes due January 2018 [Member]
Debt Instrument [Line Items]
Aggregate principal amount outstanding		250,500,000	250,500,000	733,600,000
Premium Paid			16,900,000
Senior Notes with Offers Tendered [Member] \| Senior Unsecured 6 5/8% Notes due October 2020 [Member]
Debt Instrument [Line Items]
Aggregate principal amount outstanding		28,200,000	28,200,000	309,900,000
Premium Paid			10,500,000
Senior Notes with Offers Tendered [Member] \| Senior Unsecured 6 7/8% Notes due February 2021 [Member]
Debt Instrument [Line Items]
Aggregate principal amount outstanding		$ 105,100,000	105,100,000	$ 478,600,000
Premium Paid			$ 14,400,000