Available financing of receivables purchase agreement.

No definition available.

Name:	am_AvailableFinancingOfReceivablesPurchaseAgreement
Namespace Prefix:	am_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Details

Name:	am_DebtDisclosureLineItems
Namespace Prefix:	am_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Line of credit facility additional borrowing capacity.

+ References

No definition available.

+ Details

Name:	am_LineOfCreditFacilityAdditionalBorrowingCapacity
Namespace Prefix:	am_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Line of credit facility current interest rate.

+ References

No definition available.

+ Details

Name:	am_LineOfCreditFacilityCurrentInterestRate
Namespace Prefix:	am_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Receivable purchase facility amount outstanding.

+ References

No definition available.

+ Details

Name:	am_ReceivablePurchaseFacilityAmountOutstanding
Namespace Prefix:	am_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Term loan facility first installment payment.

+ References

No definition available.

+ Details

Name:	am_TermLoanFacilityFirstInstallmentPayment
Namespace Prefix:	am_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Term loan facility periodic payment.

+ References

No definition available.

+ Details

Name:	am_TermLoanFacilityPeriodicPayment
Namespace Prefix:	am_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Amount of short-term debt and current maturity of long-term debt and capital lease obligations due within one year or the normal operating cycle, if longer.

+ 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 210.5-02.19,20)

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

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 19

-Article 5

+ Details

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

- 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

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

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 835

-SubTopic 30

-Section 45

-Paragraph 2

-URI http://asc.fasb.org/extlink&oid=6451184&loc=d3e28551-108399

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 835

-SubTopic 30

-Section 55

-Paragraph 8

-URI http://asc.fasb.org/extlink&oid=6584090&loc=d3e28878-108400

+ Details

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

- Definition

Fair value portion of debt instrument payable, including, but not limited to, notes payable and loans payable.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 825

-SubTopic 10

-Section 50

-Paragraph 10

-Subparagraph (a)

-URI http://asc.fasb.org/extlink&oid=28364263&loc=d3e13433-108611

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 825

-SubTopic 10

-Section 50

-Paragraph 12

-URI http://asc.fasb.org/extlink&oid=28364263&loc=d3e13476-108611

+ Details

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

- Definition

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

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 22

-Article 5

Reference 2: 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

The amount of debt discount that was originally recognized at the issuance of the instrument that has yet to be amortized.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 835

-SubTopic 30

-Section 45

-Paragraph 1A

-URI http://asc.fasb.org/extlink&oid=6451184&loc=d3e28541-108399

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 835

-SubTopic 30

-Section 55

-Paragraph 8

-URI http://asc.fasb.org/extlink&oid=6584090&loc=d3e28878-108400

+ Details

Name:	us-gaap_DebtInstrumentUnamortizedDiscount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

The total amount of the contingent obligation under letters of credit outstanding as of the reporting date.

+ References

No definition available.

+ Details

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

- 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

Amount of current borrowing capacity under the credit facility considering any current restrictions on the amount that could be borrowed (for example, borrowings may be limited by the amount of current assets), but without considering any 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

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 19, 22

-Article 5

+ Details

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

- Definition

Carrying amount of long-term debt, net of unamortized discount or premium, excluding amounts to be repaid within one year or the normal operating cycle, if longer (current maturities). Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 22

-Article 5

Reference 2: 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)

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

+ Details

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

Debt - Additional Information (Detail) (USD $)					9 Months Ended			0 Months Ended	9 Months Ended		12 Months Ended					9 Months Ended		9 Months Ended
Debt - Additional Information (Detail) (USD $)	Nov. 29, 2013	Aug. 09, 2013	Feb. 28, 2013	Nov. 23, 2012	Nov. 29, 2013 First Installment [Member]	Nov. 29, 2013 Future Quarterly Installment Payments [Member]	Aug. 09, 2013 Credit Agreement [Member]	Aug. 09, 2013 Accounts Receivable Facility [Member]	Nov. 29, 2013 Accounts Receivable Facility [Member]	Nov. 23, 2012 Accounts Receivable Facility [Member]	Feb. 28, 2013 Accounts Receivable Facility [Member]	Nov. 29, 2013 7.375% Senior Notes, Due 2021 [Member]	Feb. 28, 2013 7.375% Senior Notes, Due 2021 [Member]	Nov. 23, 2012 7.375% Senior Notes, Due 2021 [Member]	Nov. 30, 2011 7.375% Senior Notes, Due 2021 [Member]	Nov. 29, 2013 Term Loan Facility [Member]	Aug. 09, 2013 Term Loan Facility [Member]	Nov. 29, 2013 Revolving Credit Facility [Member]	Aug. 09, 2013 Revolving Credit Facility [Member]	Nov. 29, 2013 Letters of Credit [Member]	Nov. 29, 2013 Publicly Traded [Member]	Feb. 28, 2013 Publicly Traded [Member]	Nov. 23, 2012 Publicly Traded [Member]	Nov. 29, 2013 Non Publicly Traded [Member]	Feb. 28, 2013 Non Publicly Traded [Member]	Nov. 23, 2012 Non Publicly Traded [Member]
Debt Disclosure [Line Items]
Debt due within one year	$ 20,000,000		$ 0	$ 0
Interest on line of credit facility borrowings																4.00%		3.20%
Current borrowing capacity							600,000,000										350,000,000		250,000,000	150,000,000
Balances outstanding under the revolving credit facility																				27,300,000
Aggregate principal amount of senior notes															225,000,000
Interest rate of debt												7.375%	7.375%	7.375%	7.375%
Fair value of Corporations publicly and non-publicly traded debt																					228,800,000	233,600,000	241,900,000	427,300,000	61,200,000	131,700,000
Carrying value of Corporations traded debt	622,328,000		286,381,000	356,832,000																	225,200,000	225,200,000	225,200,000	427,300,000	61,200,000	131,700,000
Installment payment					10,000,000
Scheduled payments						5,000,000
Loan Facility and the Revolving Credit Facility	150,000,000
Discount amount on term loan facility		10,800,000
Available financing of receivables purchase agreement									50,000,000
Balances outstanding under the amended and restated receivables purchase agreement									$ 0	$ 0	$ 0
Federal fund rate								0.50%
Annual facility fee								80.00%