Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2014
Interest and dividend income
Loans	$ 370,444	$ 338,458	$ 324,610
Taxable securities	23,249	22,973	26,363
Nontaxable securities	230	51	80
Dividends on securities	1,201	1,247	968
Federal funds sold and other	574	652	455
Total interest and dividend income	395,698	363,381	352,476
Interest expense
Deposits	25,114	23,362	25,764
Securities sold under agreements to repurchase	519	563	600
FHLB advances and other borrowings	4,154	3,631	3,452
Related party notes payable	0	771	921
Subordinated debentures and subordinated notes payable	3,737	1,557	1,315
Total interest expense	33,524	29,884	32,052
Net interest income	362,174	333,497	320,424
Provision for loan and lease losses	16,955	19,041	684
Net interest income after provision for loan losses	345,219	314,456	319,740
Noninterest income
Service charges and other fees	46,209	39,134	40,204
Wealth management fees	7,283	7,412	7,228
Mortgage banking income, net	7,261	6,694	5,539
Net gain on sale of securities	160	310	90
Net increase in fair value of loans at fair value	26,314	36,742	11,904
Net realized and unrealized (loss) on derivatives	(48,658)	(62,088)	(30,177)
Other	3,968	5,686	4,993
Total noninterest income	42,537	33,890	39,781
Noninterest expense
Salaries and employee benefits	109,055	100,646	95,105
Data processing	21,719	19,531	19,548
Occupancy expenses, net	15,759	14,809	17,526
Professional fees	13,572	14,024	12,233
Communication expenses	3,721	4,455	4,510
Advertising	4,267	3,940	4,746
Equipment expenses	3,795	3,905	4,350
Net loss recognized on repossessed property and other related expenses	1,263	5,382	8,644
Amortization of core deposits and other intangibles	3,264	7,110	16,215
Acquisition expenses	15,692	0	0
Other	15,533	12,992	17,345
Total noninterest expense	207,640	186,794	200,222
Income before income taxes	180,116	161,552	159,299
Provision for income taxes	58,863	52,487	54,347
Net income	121,253	109,065	104,952
Other comprehensive income - change in net unrealized gain on securities available-for-sale (net of deferred income tax (expense) of $(1,971), $(5,194) and $(386) in 2016, 2015 and 2014, respectively)	3,216	8,475	924
Comprehensive income	$ 124,469	$ 117,540	$ 105,876
Basic earnings per common share
Weighted average shares outstanding, basic (in shares)	56,563,438	57,455,693	57,886,114
Basic earnings per share (in dollars per share)	$ 2.14	$ 1.90	$ 1.81
Diluted earnings per common share
Weighted average shares outstanding, diluted (in shares)	56,729,350	57,500,878	57,886,114
Diluted earnings per share (in dollars per share)	$ 2.14	$ 1.90	$ 1.81
Dividends per share
Dividends paid	$ 31,419	$ 20,520	$ 102,000
Dividends per share (in dollars per share)	$ 0.5588402961	$ 0.3568641161	$ 1.7620806261