Unaudited Condensed Consolidated Statement Of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Statement of Comprehensive Income [Abstract]
Net income	$ 112,992	$ 71,925	$ 281,879	$ 228,622
Derivative financial instruments:
Unrealized holding gains (losses)	(2,870)	96	87	(1,228)
Gains/(losses) reclassified to net income	(216)	363	(483)	1,284
Total other comprehensive income (loss)	(3,086)	459	(396)	56
Comprehensive income	$ 109,906	$ 72,384	$ 281,483	$ 228,678