Commitments and Contingencies - Additional Information (Detail) (USD $)	12 Months Ended
	Sep. 30, 2013 Milestone Licenses	Sep. 30, 2012	Sep. 30, 2011
Other Commitments [Line Items]
Aggregate minimum payments over the initial lease term	$ 19,294,515
Rent expense, excluding other area charges	1,100,000	2,000,000	1,900,000
Sublease rent income	294,000	997,000	961,000
Milestones	75,000
Royalty ranging, Minimum	5.00%
Royalty ranging, Maximum	8.00%
Number of maximum milestones	10
Maximum payments for milestone	1,100,000
Number of specific licensed medical indication	5
Milestones range, Minimum	75,000
Milestones range, Maximum	125,000
Milestone and royalty payments clinical, minimum	2,000,000
Milestone and royalty payments clinical, maximum	6,000,000
Milestone and royalty payments regulatory, minimum	1,500,000
Milestone and royalty payments regulatory, maximum	15,000,000
Milestone and royalty payments commercial targets, minimum	25,000,000
Milestone and royalty payments commercial targets, maximum	60,000,000
Milestone and royalty payments, aggregate	200,000,000
Royalty payments are tiered, minimum	1,000,000,000
Paid milestone agreement expenses	2,000,000
Up-front cash payment	20,000,000
Maximum additional payments from future milestones	90,000,000
U.S. 282 Patent [Member]
Other Commitments [Line Items]
Patent expiration date	Aug. 01, 2026
U.S. 484 Patent [Member]
Other Commitments [Line Items]
Patent expiration date	Jul. 01, 2023
RE 115 Patent [Member]
Other Commitments [Line Items]
Patent expiration date	Jan. 01, 2016
November 2013 [Member]
Other Commitments [Line Items]
Office space commencing	61,000
Aggregate minimum payments over the initial lease term	14,300,000
Initial lease term	86 months
Aliso Viejo [Member]
Other Commitments [Line Items]
Office space commencing	38,000
Aggregate minimum payments over the initial lease term	$ 5,000,000