Fair Value Measures (Changes in Fair Value of Contingent Earn-Out Liabilities) (Detail) (USD $)	3 Months Ended	6 Months Ended
	Mar. 31, 2014	Mar. 31, 2014
Fair Value Disclosures [Abstract]
Business Combination, Contingent Consideration Arrangements, Range of Outcomes, Value, High	$ 18,900,000	$ 18,900,000
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Settlements	(661,000)	(661,000)
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability, Purchases	7,438,000	8,307,000
Balance at beginning of period	1,319,000	450,000
Balance at end of period	$ 8,096,000	$ 8,096,000