Revenue Recognition (Analysis of Product Return Liability) (Details) - USD ($) $ in Thousands	3 Months Ended
Mar. 31, 2016	Mar. 31, 2015
Revenue Recognition
Beginning balance	$ 2,621	$ 2,408
Provision for product returns	(255)	803
Credits issued to third parties	(493)	(630)
Ending balance	$ 1,873	$ 2,581
Aggregate product return rate	1.10%	1.10%

Represents the aggregate product return rate percentage of qualified sales.

No definition available.

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Period Type:	duration

- Definition

Represents the provision for sales returns liability during the period.

+ References

No definition available.

+ Details

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Namespace Prefix:	amph_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- References

No definition available.

+ Details

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Period Type:	duration

- Definition

Amount of estimated sales returns.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 235
-SubTopic 10
-Section 50
-Paragraph 3
-URI http://asc.fasb.org/extlink&oid=51655414&loc=d3e18780-107790

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 605
-SubTopic 15
-Section 45
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=51671139&loc=d3e47468-111626

+ Details

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- Definition

Total deduction from sales during the period arising from goods returned by customers (other than under warranty provisions) and price reductions (allowance, price protection agreements) given by the entity. Returns and allowances are a deduction from gross revenue in arriving at net revenue.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 225
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03.1(a))
-URI http://asc.fasb.org/extlink&oid=26872669&loc=d3e20235-122688

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration