CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (Unaudited) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Dec. 31, 2012		Dec. 31, 2011
Net income	$ 60,206		$ 57,357
Other comprehensive income, net of tax
Unrealized (loss) gain on available for sale securities, net of tax of $221 and $(600), respectively (1)	(320)	[1]	869	[1]
Net unrealized (loss) on derivatives, net of tax of $6 and $23, respectively	(10)		(40)
Adjustment to postemployment benefit obligation, net of tax of $(203) and $(150), respectively	413		219
Other comprehensive income	83		1,048
Comprehensive income	$ 60,289		$ 58,405

[1] Available for sale securities are included in other noncurrent assets on the Unaudited Condensed Consolidated Balance Sheets.