Accumulated Other Comprehensive Income (Schedule of Reclassification out of Accumulated Other Comprehensive Income) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Reclassification out of Accumulated Other Comprehensive Income [Line Items]
Gain on sale of investments	$ 7,280	$ 0	$ 9,339	$ 0
Provision for income taxes	(5,215)	(2,454)	(9,619)	(5,404)
Consolidated net income	7,246	3,147	13,014	10,513
Amount Reclassified from Accumulated Other Comprehensive Income | Unrealized Holding Gains (Losses) on Available-for-Sale Investments
Reclassification out of Accumulated Other Comprehensive Income [Line Items]
Gain on sale of investments	4,428		5,232
Provision for income taxes	(2,057)		(2,193)
Consolidated net income	$ 2,371		$ 3,039