Accounts Receivable Credit Period

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Cash Discount Invoice Terms

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Cash Discount Percent

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Change In Control Obligations

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Class Of Warrant Expiration Date

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Derivative Amount Outstanding

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Fair Value Assumptions, Comparable Yield to Maturity

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Fair Value Assumptions Coupon Rate

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Maturity Period Used to Classify Investments

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Significant Assumptions in Market Price Of Stock

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Unrealized Gain on Derivatives

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Write Offs Of Accounts Receivables

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

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The carrying amount of consideration received or receivable as of the balance sheet date on potential earnings that were not recognized as revenue in conformity with GAAP, and which are expected to be recognized as such within one year or the normal operating cycle, if longer, including sales, license fees, and royalties, but excluding interest income.

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Fair value, after the effects of master netting arrangements, of a financial liability or contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset, expected to be settled within one year or normal operating cycle, if longer. Includes assets not subject to a master netting arrangement and not elected to be offset.

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Fair value as of the balance sheet date of the embedded derivative or group of embedded derivatives classified as a liability.

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Amount of expense (income) related to adjustment to fair value of warrant liability.

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Expected dividends to be paid to holders of the underlying shares or financial instruments (expressed as a percentage of the share or instrument's price).

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Period the instrument, asset or liability is expected to be outstanding, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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Measure of dispersion, in percentage terms (for instance, the standard deviation or variance), for a given stock price.

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Risk-free interest rate assumption used in valuing an instrument.

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The increase (decrease) during the period in the carrying value of derivative instruments reported as liabilities that are due to be disposed of within one year (or the normal operating cycle, if longer).

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Number of operating segments. An operating segment is a component of an enterprise: (a) that engages in business activities from which it may earn revenues and incur expenses (including revenues and expenses relating to transactions with other components of the same enterprise), (b) whose operating results are regularly reviewed by the enterprise's chief operating decision maker to make decisions about resources to be allocated to the segment and assess its performance, and (c) for which discrete financial information is available. An operating segment may engage in business activities for which it has yet to earn revenues, for example, start-up operations may be operating segments before earning revenues.

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Minimum amount of other commitment not otherwise specified in the taxonomy. Excludes commitments explicitly modeled in the taxonomy, including but not limited to, long-term and short-term purchase commitments, recorded and unrecorded purchase obligations, supply commitments, registration payment arrangements, leases, debt, product warranties, guarantees, environmental remediation obligations, and pensions.

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Price of a single share of a number of saleable stocks of a company.

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The net change in the difference between the fair value and the carrying value, or in the comparative fair values, of derivative instruments, including options, swaps, futures, and forward contracts, held at each balance sheet date, that was included in earnings for the period.

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Significant Accounting Policies - Additional Information (Detail) (USD $)	1 Months Ended	12 Months Ended
	Oct. 31, 2009	Dec. 31, 2014 Segment	Dec. 31, 2013	Dec. 31, 2012	May 31, 2014
Significant Accounting Policies [Line Items]
Deferred revenue		$ 0us-gaap_DeferredRevenueCurrent	$ 1,703,000us-gaap_DeferredRevenueCurrent
Sales discount percentage		2.00%amrn_CashDiscountPercent
Sales discount term		30 days
Trade receivables, credit period		30 days
Accounts receivable written off		0amrn_WriteOffsOfAccountsReceivables	0amrn_WriteOffsOfAccountsReceivables
Warrant derivative liability	48,300,000us-gaap_DerivativeLiabilitiesCurrent	119,000us-gaap_DerivativeLiabilitiesCurrent	6,894,000us-gaap_DerivativeLiabilitiesCurrent
Derivative liability fair value assumptions, risk-free rate	2.37%	0.04%	0.12%
Derivative liability fair value assumptions, term	5 years	1 month 28 days	9 months 18 days
Derivative liability fair value assumptions, dividend yield	0.00%	0.00%	0.00%
Derivative liability fair value assumptions, volatility rate	119.00%	79.00%	99.00%
Warrants expiration date	Feb. 27, 2015
Gain (loss) on change in fair value of derivative liability		13,472,000us-gaap_UnrealizedGainLossOnDerivatives	47,710,000us-gaap_UnrealizedGainLossOnDerivatives	(35,344,000)us-gaap_UnrealizedGainLossOnDerivatives
Market price of common stock		$ 0.98us-gaap_SharePrice
Hypothetical increase in market price of common shares		10.00%
Long term debt redemption feature				14,600,000
Number of operating segments		1us-gaap_NumberOfOperatingSegments
Prior To Agreement
Significant Accounting Policies [Line Items]
Warrants expiration date	Oct. 16, 2014
Foreign Exchange Contract
Significant Accounting Policies [Line Items]
Derivative, amount outstanding		0
Embedded Derivative Financial Instruments
Significant Accounting Policies [Line Items]
Gain (loss) on change in fair value of derivative liability		7,200,000	3,477,000
Change of control obligation				140,000,000
Maximum repayment of future revenue and receivables				150,000,000
Long term debt redemption feature		4,800,000	11,100,000
Gain on change in fair value of derivative liability		6,300,000
Effect of a hypothetical 10% increase in the market price of common shares
Significant Accounting Policies [Line Items]
Increase (Decrease) in the fair value of warrant derivative liability		100,000
Market price of common stock		$ 1.08
Convertible Debt
Significant Accounting Policies [Line Items]
Carrying value include debt discount		3,500,000
Gain (loss) on change in fair value of derivative liability		900,000
Convertible Debt \| 2014 Notes
Significant Accounting Policies [Line Items]
Carrying value include debt discount		27,900,000			27,900,000
Derivative liability fair value assumptions, risk-free rate		2.70%
Derivative liability fair value assumptions, dividend yield		24.80%
Derivative liability fair value assumptions, volatility rate		82.00%
Gain (loss) on change in fair value of derivative liability		900,000
Long term debt redemption feature		2,600,000
Convertible Debt \| 2012 Notes
Significant Accounting Policies [Line Items]
Carrying value include debt discount		0	700,000
Convertible Debt \| Non Cash \| 2014 Notes
Significant Accounting Policies [Line Items]
Carrying value include debt discount		28,200,000
Warrants Issued October 2009
Significant Accounting Policies [Line Items]
Warrants expiration date		Feb. 27, 2015
Increase (Decrease) in the fair value of warrant derivative liability		6,800,000	47,900,000
Gain (loss) on change in fair value of derivative liability		6,300,000	44,200,000
Compensation expense (income) for change in fair value of warrants issued to former employees		$ 500,000	$ 3,700,000
Warrants Issued October 2009 \| Prior To Agreement
Significant Accounting Policies [Line Items]
Warrants expiration date		Oct. 16, 2014
Top Three Customers \| Gross Product Sales \| Customer Concentration Risk
Significant Accounting Policies [Line Items]
Concentration risk percentage		95.00%	96.00%
Top Three Customers \| Accounts Receivable \| Customer Concentration Risk
Significant Accounting Policies [Line Items]
Concentration risk percentage		96.00%	95.00%
Minimum \| Embedded Derivative Financial Instruments
Significant Accounting Policies [Line Items]
Derivative liability fair value assumptions, term		2 years 3 months 18 days	3 years 3 months 18 days
Derivative liability fair value assumption, coupon rate		9.80%	9.90%
Derivative liability fair value assumptions, market yields		10.00%	9.00%
Maximum
Significant Accounting Policies [Line Items]
Short term highly liquid instruments, maturity date		90 days
Maximum \| Embedded Derivative Financial Instruments
Significant Accounting Policies [Line Items]
Derivative liability fair value assumptions, term		3 years 7 months 6 days	6 years 7 months 6 days
Derivative liability fair value assumption, coupon rate		10.80%	12.50%
Derivative liability fair value assumptions, market yields		16.80%	29.40%