Accumulated Other Comprehensive Income (Schedule of Accumulated Other Comprehensive Income (Loss)) (Details) (USD $) In Thousands, unless otherwise specified	6 Months Ended
	Mar. 31, 2013
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning Balance	$ 2,399	[1]
Other comprehensive income before reclassifications	7,596
Amounts reclassified out of accumulated other comprehensive income	(648)
Other comprehensive income (loss)	6,948
Ending Balance	9,347
Unrealized Holding Gains (Losses) on Available-for-Sale Investments
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning Balance	(1,523)
Other comprehensive income before reclassifications	9,935
Amounts reclassified out of accumulated other comprehensive income	(668)
Other comprehensive income (loss)	9,267
Ending Balance	7,744
Transition Obligation Credits
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning Balance	115
Other comprehensive income before reclassifications	0
Amounts reclassified out of accumulated other comprehensive income	(30)
Other comprehensive income (loss)	(30)
Ending Balance	85
Actuarial Losses
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning Balance	(2,241)
Other comprehensive income before reclassifications	0
Amounts reclassified out of accumulated other comprehensive income	50
Other comprehensive income (loss)	50
Ending Balance	(2,191)
Foreign Currency Translation Adjustment
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning Balance	6,048
Other comprehensive income before reclassifications	(2,339)
Amounts reclassified out of accumulated other comprehensive income	0
Other comprehensive income (loss)	(2,339)
Ending Balance	$ 3,709

[1] Derived from audited financial statements.