Executive Compensation Plan - Additional Information (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended	6 Months Ended
Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Executive Compensation Plan Expense [Line Items]
Deferred executive compensation plan, grant date value of awards			$ 0
Deferred executive compensation plan, net expense	$ 351	$ 644	$ 683	$ 1,500

The compensation expense recognized during the period related to the deferred executive compensation plan.

No definition available.

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