v3.8.0.1

Commitments and Contingencies Contingencies (Details) $ in Millions	3 Months Ended
	Sep. 30, 2017 USD ($)
Accounts Payable and Accrued Liabilities [Member] | Operating Expense [Member] | Tioga, North Dakota Crude Oil Pipeline Release [Member] | Judicial Ruling [Member] | Unfavorable Regulatory Action [Member]
Loss Contingencies [Line Items]
Loss Contingency Accrual, Period Increase (Decrease)	$ 19

X

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

X

- Definition

Amount of increase (decrease) in loss contingency liability.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 450
-SubTopic 20
-Section 50
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=25496072&loc=d3e14326-108349

+ Details

Name:	us-gaap_LossContingencyAccrualCarryingValuePeriodIncreaseDecrease
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	na
Period Type:	duration

X

- Details

Name:	us-gaap_BalanceSheetLocationAxis=us-gaap_AccountsPayableAndAccruedLiabilitiesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_IncomeStatementLocationAxis=us-gaap_OperatingExpenseMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_LitigationCaseAxis=andx_TiogaNorthDakotaCrudeOilPipelineReleaseMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_LitigationStatusAxis=us-gaap_SettledLitigationMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_LossContingenciesByNatureOfContingencyAxis=us-gaap_UnfavorableRegulatoryActionMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: