Consolidated Statements Of Comprehensive Income (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Mar. 31, 2014	Mar. 31, 2013	Mar. 31, 2014	Mar. 31, 2013
Consolidated Statements Of Comprehensive Income [Abstract]
Net income	$ 19,688	$ 17,715	$ 37,501	$ 35,278
Other comprehensive income (loss), net of tax:
Changes in unrealized holding gains/(losses) on AFS securities, net of deferred income tax (benefits) expenses of $(279) and $1,594 for the three months ended March 31, 2014 and 2013, respectively, and $1,363 and $3,907 for the six months ended March 31, 2014 and 2013, respectively	459	(2,621)	(2,241)	(6,426)
Comprehensive income	$ 20,147	$ 15,094	$ 35,260	$ 28,852