OPERATING AND GEOGRAPHICAL SEGMENTS Reconciliation of Segment Information to Consolidated Statements of Operations (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
Mar. 31, 2015	Mar. 31, 2014
Reconciliation of Segment Information to Condensed Consolidated Statements of Operations
Segment income from operations	$ 40,686atml_SegmentOperatingIncomeLoss	$ 30,070atml_SegmentOperatingIncomeLoss
Unallocated amounts:
Share-based compensation expense	(13,687)	(15,617)
Loss from manufacturing facility damage and shutdown	0	(7,056)
Acquisition-related charges	(4,403)	(1,628)
French building (underutilization) and other credits	288atml_Frenchbuildingunderutilization	(1,296)atml_Frenchbuildingunderutilization
Restructuring (charges) credits	(1,147)us-gaap_RestructuringCharges	224us-gaap_RestructuringCharges
(Loss) gain related to foundry arrangements	(1,192)atml_Gainfromfoundryarrangement	58atml_Gainfromfoundryarrangement
Consolidated income from operations	20,545us-gaap_OperatingIncomeLoss	4,755us-gaap_OperatingIncomeLoss
Micro-Controllers
Reconciliation of Segment Information to Condensed Consolidated Statements of Operations
Segment income from operations	23,756	18,826
Nonvolatile Memories
Reconciliation of Segment Information to Condensed Consolidated Statements of Operations
Segment income from operations	11,670	5,047
RF and Automotive
Reconciliation of Segment Information to Condensed Consolidated Statements of Operations
Segment income from operations	3,297	6,754
Multi-market and other
Reconciliation of Segment Information to Condensed Consolidated Statements of Operations
Segment income from operations	$ 1,963	$ (557)
Sales Revenue, Goods, Net [Member] \| Credit Concentration Risk [Member] \| Major Customer with Largest Balance [Member]
Segment Reporting Information [Line Items]
Concentration Risk, Percentage	10.00%	10.00%

French building underutilization

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- Definition

Gain from foundry arrangement

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No definition available.

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- Definition

Loss from manufacturing facility damage and shutdown

+ References

No definition available.

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- Definition

Amount of income or loss for the reportable segment before unusual Items, equity method income or loss, income taxes, and extraordinary items.

+ References

No definition available.

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- Definition

Represents the expense recognized during the period arising from equity-based compensation arrangements (for example, shares of stock, unit, stock options or other equity instruments) with employees, directors and certain consultants qualifying for treatment as employees.

+ References

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- Definition

This element represents acquisition-related costs incurred to effect a business combination which costs have been expensed during the period. Such costs include finder's fees; advisory, legal, accounting, valuation, and other professional or consulting fees; general administrative costs, including the costs of maintaining an internal acquisitions department; and may include costs of registering and issuing debt and equity securities.

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- Definition

For an entity that discloses a concentration risk in relation to quantitative amount, which serves as the "benchmark" (or denominator) in the equation, this concept represents the concentration percentage derived from the division.

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- Definition

The net result for the period of deducting operating expenses from operating revenues.

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No definition available.

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- Definition

Amount of expenses associated with exit or disposal activities pursuant to an authorized plan. Excludes expenses related to a discontinued operation or an asset retirement obligation.

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-Number Topic 5

-Section P

-Subsection 3, 4

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