Long Term Obligations - Additional Information (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended	6 Months Ended
Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011
Debt Instrument [Line Items]
Term loan, period			5 years
Weighted-average interest rate for five year Term Loan	1.30%	1.00%	1.20%	1.00%
Total leverage ratio	1.2		1.2
Fixed charge coverage ratio	1.4		1.4
Amount of Revolving Credit Facility	$ 250.0		$ 250.0
Availability under the revolving credit facility	229.5		229.5
Outstanding letters of credit	$ 20.5		$ 20.5
Revolving Credit Facilities
Debt Instrument [Line Items]
Revolving credit facility, maturity date			2013-03-26

Debt Instruments, Maturity Date

No definition available.

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- Definition

Ratio of adjusted earnings before interest, taxes , depreciation and amortization plus rent expense to certain fixed charges (interest expense, required principal payments and capital expenditures).

+ References

No definition available.

+ Details

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- Definition

Amount of a short-term or long-term contractual arrangement with a lender, including letter of credit, standby letter of credit, and revolving credit arrangements, under which borrowings can be made up to maximum amount as of any point in time conditional on satisfaction of specified terms before, as of and after the date of drawdowns on the line of credit.

+ References

No definition available.

+ Details

Name:	amed_RevolvingCreditFacilityTotal
Namespace Prefix:	amed_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Period of term loan

+ References

No definition available.

+ Details

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

- Definition

Reflects the calculation as of the average interest rate weighted by the amount outstanding at the balance sheet date.

+ References

No definition available.

+ Details

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Balance Type:	na
Period Type:	duration

- Definition

Ratio of debt to earnings before interest, taxes, depreciation and amortization.

+ References

No definition available.

+ Details

Name:	amed_TotalLeverageRatio
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Data Type:	xbrli:decimalItemType
Balance Type:	na
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- Details

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- Definition

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

+ References

No definition available.

+ Details

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

- Definition

Amount of borrowing capacity currently available under the credit facility (current borrowing capacity less the amount of borrowings outstanding).

+ 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

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Balance Type:	credit
Period Type:	instant