Proceeds obtained expressed as a percentage of debt instrument face value.

No definition available.

Name:	a_PercentageOfFaceAmountOfSeniorNoteInstrumentIssued
Namespace Prefix:	a_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Date the debt agreement requires the first payment to be made, in CCYY-MM-DD format.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.22)
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Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
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-Section 50
-Paragraph 3
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=75038535&loc=d3e64711-112823

+ Details

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

- Definition

Face (par) amount of debt instrument at time of issuance.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 45
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-SubTopic 30
-Section 55
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-URI http://asc.fasb.org/extlink&oid=114775985&loc=d3e28878-108400

+ Details

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

- Definition

Description of the frequency of periodic payments (monthly, quarterly, annual).

+ References

+ Details

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

- Definition

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

+ References

+ Details

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

- Definition

Date the debt instrument was issued, in CCYY-MM-DD format.

+ References

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:dateItemType
Balance Type:	na
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_DebtInstrumentLineItems
Namespace Prefix:	us-gaap_
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/disclosureRef
-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

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 820
-SubTopic 10
-Section 50
-Paragraph 2
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-URI http://asc.fasb.org/extlink&oid=99377789&loc=d3e19207-110258

+ Details

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

- Details

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Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

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Balance Type:
Period Type:

- Details

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Balance Type:
Period Type:

- Details

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LONG-TERM DEBT - Senior Notes and Mortgage (Details) - USD ($) $ in Millions	Sep. 15, 2016	Jun. 18, 2013	Sep. 10, 2012	Jul. 13, 2010	Oct. 24, 2007	Aug. 09, 2011
Senior Notes 2017 [Member]
Debt Instrument [Line Items]
Issuance date of debt					Oct. 24, 2007
Aggregate face amount of debt					$ 600
Senior Notes 2020 [Member]
Debt Instrument [Line Items]
Issuance date of debt				Jul. 13, 2010
Aggregate face amount of debt				$ 500		$ 500
Issue rate percentage of principal amount				99.54%
Maturity date				Jul. 15, 2020
Fixed interest rate per annum (in hundredths)				5.00%
Interest payment frequency				semi-annually
Date payments commenced				Jan. 15, 2011
Senior Notes 2022 [Member]
Debt Instrument [Line Items]
Issuance date of debt			Sep. 10, 2012
Aggregate face amount of debt			$ 400
Issue rate percentage of principal amount			99.80%
Maturity date			Oct. 01, 2022
Fixed interest rate per annum (in hundredths)			3.20%
Interest payment frequency			semi-annually
Date payments commenced			Apr. 01, 2013
Senior Notes 2023 [Member]
Debt Instrument [Line Items]
Issuance date of debt		Jun. 18, 2013
Aggregate face amount of debt		$ 600
Issue rate percentage of principal amount		99.544%
Maturity date		Jul. 15, 2023
Fixed interest rate per annum (in hundredths)		3.875%
Interest payment frequency		semi-annually
Date payments commenced		Jan. 15, 2014
Senior Notes 2026 [Member]
Debt Instrument [Line Items]
Issuance date of debt	Sep. 15, 2016
Aggregate face amount of debt	$ 300
Issue rate percentage of principal amount	99.624%
Maturity date	Sep. 22, 2026
Fixed interest rate per annum (in hundredths)	3.05%
Interest payment frequency	semi-annually
Date payments commenced	Mar. 22, 2017