Fair Value Measurements (Details) (USD $)	3 Months Ended	6 Months Ended
	Mar. 31, 2013	Mar. 31, 2013	Mar. 31, 2013 Estimate of Fair Value, Fair Value Disclosure [Member] Fair Value, Measurements, Recurring [Member]	Sep. 30, 2012 Estimate of Fair Value, Fair Value Disclosure [Member] Fair Value, Measurements, Recurring [Member]	Mar. 31, 2012 Estimate of Fair Value, Fair Value Disclosure [Member] Fair Value, Measurements, Recurring [Member]	Mar. 31, 2013 Level 1 [Member] Fair Value, Measurements, Recurring [Member]	Sep. 30, 2012 Level 1 [Member] Fair Value, Measurements, Recurring [Member]	Mar. 31, 2012 Level 1 [Member] Fair Value, Measurements, Recurring [Member]	Mar. 31, 2013 Level 2 [Member] Fair Value, Measurements, Recurring [Member]	Sep. 30, 2012 Level 2 [Member] Fair Value, Measurements, Recurring [Member]	Mar. 31, 2012 Level 2 [Member] Fair Value, Measurements, Recurring [Member]	Mar. 31, 2013 Level 3 [Member] Fair Value, Measurements, Recurring [Member]	Sep. 30, 2012 Level 3 [Member] Fair Value, Measurements, Recurring [Member]	Mar. 31, 2012 Level 3 [Member] Fair Value, Measurements, Recurring [Member]
Financial assets that are measured at fair value on a recurring basis
Marketable equity securities			$ 4,367,000	$ 4,631,000	$ 4,628,000	$ 4,367,000	$ 4,631,000	$ 4,628,000	$ 0	$ 0	$ 0	$ 0	$ 0	$ 0
Contingent consideration			(23,678,000)	(23,432,000)	(23,000,000)	0	0	0	0	0	0	(23,678,000)	(23,432,000)	(23,000,000)
Net financial assets (liabilities)			(19,311,000)	(18,801,000)	(18,372,000)	4,367,000	4,631,000	4,628,000	0	0	0	(23,678,000)	(23,432,000)	(23,000,000)
Gross unrealized losses (less than $0.1 million)	100,000	100,000
Contingent consideration, accretion expense	$ 100,000	$ 300,000