Cost Method Investment, Ownership Percentage

No definition available.

Name:	nblx_CostMethodInvestmentOwnershipPercentage
Namespace Prefix:	nblx_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Payments to Acquire Equity Method Investments, Net

+ References

No definition available.

+ Details

Name:	nblx_PaymentstoAcquireEquityMethodInvestmentsNet
Namespace Prefix:	nblx_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

The percentage of ownership of common stock or equity participation in the investee accounted for under the equity method of accounting.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 323
-SubTopic 10
-Section 50
-Paragraph 3
-Subparagraph (a)(1)
-URI http://asc.fasb.org/extlink&oid=114001798&loc=d3e33918-111571

+ Details

Name:	us-gaap_EquityMethodInvestmentOwnershipPercentage
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

The cash outflow associated with the purchase of or advances to an equity method investments, which are investments in joint ventures and entities in which the entity has an equity ownership interest normally of 20 to 50 percent and exercises significant influence.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 13
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=121586364&loc=d3e3213-108585

+ Details

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

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

- Details

Name:	srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis=nblx_WhiteCliffsPipelineMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis=nblx_AdvantageJointVentureMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis=nblx_DelawareCrossingJVMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis=nblx_EPICYGradePipelineMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis=nblx_EPICCrudeOilPipelineMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis=nblx_EPICInvestmentsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis=nblx_SaddlehornPipelineCompanyLLCMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_CounterpartyNameAxis=nblx_GreenfieldMemberMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_CounterpartyNameAxis=nblx_BlackDiamondMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_CounterpartyNameAxis=nblx_MagellanandPlainsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_CounterpartyNameAxis=nblx_BlackDiamondandWesternMidstreamMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Investments - Narrative (Details) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
Investments - Narrative (Details) - USD ($) $ in Millions	Mar. 31, 2020	Sep. 30, 2020
White Cliffs
Schedule of Equity Method Investments
Ownership percentage (percent)		3.33%
Advantage
Schedule of Equity Method Investments
Ownership interest, equity method (percent)		50.00%
Delaware Crossing
Schedule of Equity Method Investments
Ownership interest, equity method (percent)		50.00%
Capital contributions		$ 14.9
EPIC Y-Grade
Schedule of Equity Method Investments
Ownership interest, equity method (percent)		15.00%
Capital contributions		$ 29.7
EPIC Crude
Schedule of Equity Method Investments
Ownership interest, equity method (percent)		30.00%
Capital contributions		$ 54.0
EPIC Propane
Schedule of Equity Method Investments
Ownership interest, equity method (percent)		15.00%
Capital contributions		$ 8.4
Saddlehorn
Schedule of Equity Method Investments
Ownership percentage (percent)	20.00%	20.00%
Capital contributions	$ 160.0
Payments to acquire equity method investments, net	87.0
Saddlehorn \| Greenfield Member
Schedule of Equity Method Investments
Capital contributions	$ 73.0
Saddlehorn \| Black Diamond
Schedule of Equity Method Investments
Ownership percentage (percent)	10.00%
Saddlehorn \| Magellan and Plains
Schedule of Equity Method Investments
Ownership percentage (percent)	30.00%
Saddlehorn \| Black Diamond and Western Midstream
Schedule of Equity Method Investments
Ownership percentage (percent)	20.00%