Summary of Product Revenue Allowances and Reserve Categories (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
Dec. 31, 2013
Valuation Allowance [Line Items]
Provision	$ 4,059
Payments or credits	(3,449)
Ending balance	610
Trade Allowances
Valuation Allowance [Line Items]
Provision	1,158
Payments or credits	(1,140)
Ending balance	18
Rebates Chargebacks and Discounts
Valuation Allowance [Line Items]
Provision	2,721
Payments or credits	(2,206)
Ending balance	515
Other Incentives/ Returns
Valuation Allowance [Line Items]
Provision	180
Payments or credits	(103)
Ending balance	$ 77

Total of the provision for allowances and reserves in a given period, the valuation and qualifying accounts that are netted against gross revenue or that reflect a liability established to represent expected future costs.

No definition available.

+ Details

Name:	aria_ValuationAllowancesAndReservesProvision
Namespace Prefix:	aria_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Details

Name:	us-gaap_ValuationAllowanceLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Total of allowances and reserves, the valuation and qualifying accounts that are either netted against the cost of an asset (in order to value it at its carrying value) or that reflect a liability established to represent expected future costs.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 235

-SubTopic 10

-Section S99

-Paragraph 4

-URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e24092-122690

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

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 09

-Article 12

+ Details

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

- Definition

Total of the deductions in a given period to allowances and reserves, the valuation and qualifying accounts that are either netted against the cost of an asset (in order to value it at its carrying value) or that reflect a liability established to represent expected future costs, representing receivables written off as uncollectible and portions of the reserves utilized, respectively.

+ References

+ Details

Name:	us-gaap_ValuationAllowancesAndReservesDeductions
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration