Condensed Consolidated Statement Of Comprehensive Income (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Dec. 31, 2013	Dec. 31, 2012
Statement of Comprehensive Income [Abstract]
Net income	$ 83,397	$ 72,831
Other comprehensive gains (losses), net of tax:
Unrealized holding gain (loss)	(743)	(66)
Loss reclassified to net income	381	438
Total other comprehensive gain (loss)	(362)	372
Comprehensive income	$ 83,035	$ 73,203