Accrued Expenses and Other Current Liabilities (Detail) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2014	Sep. 30, 2013
Payables and Accruals [Abstract]
Compensation	$ 128,100	$ 112,756
Acquisition costs and liabilities	38,367	15,722
Accrued interest payable	26,893	15,879
Cost of revenue related liabilities	18,930	17,992
Sales and other taxes payable	13,505	10,625
Sales and marketing incentives	10,508	11,681
Professional fees	9,517	17,682
Other	17,341	12,088
Total	$ 263,161	$ 214,425