CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (UNAUDITED) (PARENTHETICALS) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Other Comprehensive Income Loss Tax Portion Attributable To Parent Abstract
Unrealized holding gains (losses) on available-for-sale securities, tax	$ (41)	$ 216	$ (170)	$ 1,518
Amortization and unrealized gains (losses) on interest rate agreements, tax	31,314	(13,472)	(17,232)	(21,005)
Net unrealized gains (losses) on commodity cash flow hedging transactions, tax	$ 7,393	$ (1,580)	$ (12,698)	$ 4,122