Deferred Tax Assets and Liabilities (Detail) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012
Deferred tax assets:
Net operating loss carryforward	$ 21,529	$ 22,120
Research credit carryforward	4,074	2,310
Capital loss carryforward	165	91
Investments	1,101	1,141
Accrued compensation	1,662	1,297
Share-based compensation	16,443	20,109
Deferred revenue	2,139	3,577
Accrued lease costs	1,127	1,774
Property and equipment	2,155	3,629
Other	7,093	14,183
Deferred Tax Assets, Gross, Total	57,488	70,231
Less valuation allowance	(8,712)	(5,425)
Total deferred tax assets	48,776	64,806
Deferred tax liabilities:
Intangible assets	(29,912)	(31,364)
Prepaid expense	(3,526)	(3,405)
Other	(1,515)	(1,019)
Total deferred tax liabilities	(34,953)	(35,788)
Deferred tax assets, net	$ 13,823	$ 29,018