Fair Value Measurements - Assets and Liabilities Measured at Fair Value on Recurring Basis (Detail) - Assets and Liabilities Measured at Fair Value on a Recurring Basis [Member] - USD ($)	Mar. 31, 2016	Sep. 30, 2015
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Assets measured at fair value	$ 31,624	$ 53,591
Liabilities measured at fair value	(13,646)
Significant Other Observable Inputs (Level 2) [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Assets measured at fair value	31,624	53,591
Significant Unobservable Inputs (Level 3) [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Liabilities measured at fair value	(13,646)
Cash equivalents [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Assets measured at fair value	31,624	53,591
Cash equivalents [Member] | Significant Other Observable Inputs (Level 2) [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Assets measured at fair value	31,624	$ 53,591
Contingent consideration - current and noncurrent [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Liabilities measured at fair value	(13,646)
Contingent consideration - current and noncurrent [Member] | Significant Unobservable Inputs (Level 3) [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Liabilities measured at fair value	$ (13,646)