Financial Instruments and Fair Value Measurements (Financial Assets that are Measured at Fair Value on a Recurring Basis) (Details) - USD ($) $ in Thousands	Jun. 30, 2015	Sep. 30, 2014
Equity securities	$ 10,399	$ 9,645
Total financial assets	97,783	124,932
Fair Value, Inputs, Level 1 [Member]
Equity securities	10,399	9,645
Total financial assets	97,783	124,932
Fair Value, Inputs, Level 2 [Member]
Equity securities	0	0
Total financial assets	0	0
Fair Value, Inputs, Level 3 [Member]
Equity securities	0	0
Total financial assets	0	0
Cash [Member]
Cash and cash equivalents	77,855	92,590
Cash [Member] | Fair Value, Inputs, Level 1 [Member]
Cash and cash equivalents	77,855	92,590
Cash [Member] | Fair Value, Inputs, Level 2 [Member]
Cash and cash equivalents	0	0
Cash [Member] | Fair Value, Inputs, Level 3 [Member]
Cash and cash equivalents	0	0
Investments in Money Market Funds [Member]
Cash and cash equivalents	4,117	11,210
Investments in Money Market Funds [Member] | Fair Value, Inputs, Level 1 [Member]
Cash and cash equivalents	4,117	11,210
Investments in Money Market Funds [Member] | Fair Value, Inputs, Level 2 [Member]
Cash and cash equivalents	0	0
Investments in Money Market Funds [Member] | Fair Value, Inputs, Level 3 [Member]
Cash and cash equivalents	0	0
Investments in Reverse Repurchase Agreements [Member]
Cash and cash equivalents	5,412	11,487
Investments in Reverse Repurchase Agreements [Member] | Fair Value, Inputs, Level 1 [Member]
Cash and cash equivalents	5,412	11,487
Investments in Reverse Repurchase Agreements [Member] | Fair Value, Inputs, Level 2 [Member]
Cash and cash equivalents	0	0
Investments in Reverse Repurchase Agreements [Member] | Fair Value, Inputs, Level 3 [Member]
Cash and cash equivalents	$ 0	$ 0