Accrued Expenses and Other Current Liabilities (Detail) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2013	Sep. 30, 2013
Payables and Accruals [Abstract]
Compensation	$ 91,875	$ 112,756
Acquisition costs and liabilities	31,546	15,722
Accrued interest payable	27,005	15,879
Cost of revenue related liabilities	18,600	17,992
Professional fees	15,881	17,682
Sales and marketing incentives	12,803	11,681
Sales and other taxes payable	11,980	10,625
Other	17,492	12,088
Total	$ 227,182	$ 214,425