Financial Instruments and Fair Value Measurements (Financial Assets that are Measured at Fair Value on a Recurring Basis) (Details) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2015	Sep. 30, 2014
Equity securities	$ 10,435	$ 9,645
Total financial assets	91,196	124,932
Fair Value, Inputs, Level 1 [Member]
Equity securities	10,435	9,645
Total financial assets	91,196	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	79,973	92,590
Cash [Member] | Fair Value, Inputs, Level 1 [Member]
Cash and cash equivalents	79,973	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	15	11,210
Investments in Money Market Funds [Member] | Fair Value, Inputs, Level 1 [Member]
Cash and cash equivalents	15	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	773	11,487
Investments in Reverse Repurchase Agreements [Member] | Fair Value, Inputs, Level 1 [Member]
Cash and cash equivalents	773	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