Loans Receivable - Risk Grades of the Loan Portfolio (Details) (USD $)	6 Months Ended
	Mar. 31, 2015	Mar. 31, 2014	Sep. 30, 2014
Composition Of Loan Portfolio [Line Items]
Loans receivable, net of undisbursed proceeds of loans in process	$ 656,212,122		$ 606,366,713
Accretion of discount	4,322,062	5,986,428
Non-covered loans
Composition Of Loan Portfolio [Line Items]
Loans receivable, net of undisbursed proceeds of loans in process	617,053,035	491,481,394	546,570,720
Non-covered loans | Pass (1-4)
Composition Of Loan Portfolio [Line Items]
Loans receivable, net of undisbursed proceeds of loans in process	584,953,691		516,894,804
Non-covered loans | Special Mention (5)
Composition Of Loan Portfolio [Line Items]
Loans receivable, net of undisbursed proceeds of loans in process	2,819,343		3,416,324
Non-covered loans | Substandard (6)
Composition Of Loan Portfolio [Line Items]
Loans receivable, net of undisbursed proceeds of loans in process	29,280,001		26,259,592
Non-covered loans | Doubtful (7)
Composition Of Loan Portfolio [Line Items]
Loans receivable, net of undisbursed proceeds of loans in process	0		0
Non-covered loans | Loss (8)
Composition Of Loan Portfolio [Line Items]
Loans receivable, net of undisbursed proceeds of loans in process	0		0
Non-covered loans | 1-4 family residential real estate
Composition Of Loan Portfolio [Line Items]
Loans receivable, net of undisbursed proceeds of loans in process	172,131,248	135,181,013	152,810,501
Non-covered loans | 1-4 family residential real estate | Pass (1-4)
Composition Of Loan Portfolio [Line Items]
Loans receivable, net of undisbursed proceeds of loans in process	169,257,202		151,661,479
Non-covered loans | 1-4 family residential real estate | Special Mention (5)
Composition Of Loan Portfolio [Line Items]
Loans receivable, net of undisbursed proceeds of loans in process	750,553		0
Non-covered loans | 1-4 family residential real estate | Substandard (6)
Composition Of Loan Portfolio [Line Items]
Loans receivable, net of undisbursed proceeds of loans in process	2,123,493		1,149,022
Non-covered loans | 1-4 family residential real estate | Doubtful (7)
Composition Of Loan Portfolio [Line Items]
Loans receivable, net of undisbursed proceeds of loans in process	0		0
Non-covered loans | 1-4 family residential real estate | Loss (8)
Composition Of Loan Portfolio [Line Items]
Loans receivable, net of undisbursed proceeds of loans in process	0		0
Non-covered loans | Commercial real estate
Composition Of Loan Portfolio [Line Items]
Loans receivable, net of undisbursed proceeds of loans in process	340,171,680	271,156,431	300,556,023
Non-covered loans | Commercial real estate | Pass (1-4)
Composition Of Loan Portfolio [Line Items]
Loans receivable, net of undisbursed proceeds of loans in process	311,500,448		273,587,373
Non-covered loans | Commercial real estate | Special Mention (5)
Composition Of Loan Portfolio [Line Items]
Loans receivable, net of undisbursed proceeds of loans in process	2,055,331		3,325,324
Non-covered loans | Commercial real estate | Substandard (6)
Composition Of Loan Portfolio [Line Items]
Loans receivable, net of undisbursed proceeds of loans in process	26,615,901		23,643,326
Non-covered loans | Commercial real estate | Doubtful (7)
Composition Of Loan Portfolio [Line Items]
Loans receivable, net of undisbursed proceeds of loans in process	0		0
Non-covered loans | Commercial real estate | Loss (8)
Composition Of Loan Portfolio [Line Items]
Loans receivable, net of undisbursed proceeds of loans in process	0		0
Non-covered loans | Commercial
Composition Of Loan Portfolio [Line Items]
Loans receivable, net of undisbursed proceeds of loans in process	29,431,806	21,500,766	24,759,682
Non-covered loans | Commercial | Pass (1-4)
Composition Of Loan Portfolio [Line Items]
Loans receivable, net of undisbursed proceeds of loans in process	28,911,206		23,205,880
Non-covered loans | Commercial | Special Mention (5)
Composition Of Loan Portfolio [Line Items]
Loans receivable, net of undisbursed proceeds of loans in process	13,459		91,000
Non-covered loans | Commercial | Substandard (6)
Composition Of Loan Portfolio [Line Items]
Loans receivable, net of undisbursed proceeds of loans in process	507,141		1,462,802
Non-covered loans | Commercial | Doubtful (7)
Composition Of Loan Portfolio [Line Items]
Loans receivable, net of undisbursed proceeds of loans in process	0		0
Non-covered loans | Commercial | Loss (8)
Composition Of Loan Portfolio [Line Items]
Loans receivable, net of undisbursed proceeds of loans in process	0		0
Non-covered loans | Real estate construction
Composition Of Loan Portfolio [Line Items]
Loans receivable, net of undisbursed proceeds of loans in process	70,758,469	47,111,623	63,485,411
Non-covered loans | Real estate construction | Pass (1-4)
Composition Of Loan Portfolio [Line Items]
Loans receivable, net of undisbursed proceeds of loans in process	70,758,469		63,485,411
Non-covered loans | Real estate construction | Special Mention (5)
Composition Of Loan Portfolio [Line Items]
Loans receivable, net of undisbursed proceeds of loans in process	0		0
Non-covered loans | Real estate construction | Substandard (6)
Composition Of Loan Portfolio [Line Items]
Loans receivable, net of undisbursed proceeds of loans in process	0		0
Non-covered loans | Real estate construction | Doubtful (7)
Composition Of Loan Portfolio [Line Items]
Loans receivable, net of undisbursed proceeds of loans in process	0		0
Non-covered loans | Real estate construction | Loss (8)
Composition Of Loan Portfolio [Line Items]
Loans receivable, net of undisbursed proceeds of loans in process	0		0
Non-covered loans | Consumer and other
Composition Of Loan Portfolio [Line Items]
Loans receivable, net of undisbursed proceeds of loans in process	4,559,832	16,531,561	4,959,103
Non-covered loans | Consumer and other | Pass (1-4)
Composition Of Loan Portfolio [Line Items]
Loans receivable, net of undisbursed proceeds of loans in process	4,526,366		4,954,661
Non-covered loans | Consumer and other | Special Mention (5)
Composition Of Loan Portfolio [Line Items]
Loans receivable, net of undisbursed proceeds of loans in process	0		0
Non-covered loans | Consumer and other | Substandard (6)
Composition Of Loan Portfolio [Line Items]
Loans receivable, net of undisbursed proceeds of loans in process	33,466		4,442
Non-covered loans | Consumer and other | Doubtful (7)
Composition Of Loan Portfolio [Line Items]
Loans receivable, net of undisbursed proceeds of loans in process	0		0
Non-covered loans | Consumer and other | Loss (8)
Composition Of Loan Portfolio [Line Items]
Loans receivable, net of undisbursed proceeds of loans in process	0		0
Covered loans
Composition Of Loan Portfolio [Line Items]
Loans receivable, net of nonaccretable differences and allowances for covered loan losses	53,423,117		75,637,900
Accretion of discount	4,322,062	5,986,428
Covered loans | Numerical risk rating (1-4)
Composition Of Loan Portfolio [Line Items]
Loans receivable, net of nonaccretable differences and allowances for covered loan losses	31,350,320		43,467,072
Covered loans | Numerical risk rating (5)
Composition Of Loan Portfolio [Line Items]
Loans receivable, net of nonaccretable differences and allowances for covered loan losses	6,467,091		9,553,968
Covered loans | Numerical risk rating (6)
Composition Of Loan Portfolio [Line Items]
Loans receivable, net of nonaccretable differences and allowances for covered loan losses	15,605,706		22,616,860
Covered loans | Numerical risk rating (7)
Composition Of Loan Portfolio [Line Items]
Loans receivable, net of nonaccretable differences and allowances for covered loan losses	0		0
Covered loans | Numerical risk rating (8)
Composition Of Loan Portfolio [Line Items]
Loans receivable, net of nonaccretable differences and allowances for covered loan losses	0		0
Covered loans | 1-4 family residential real estate
Composition Of Loan Portfolio [Line Items]
Loans receivable, net of nonaccretable differences and allowances for covered loan losses	7,454,597		10,677,336
Covered loans | 1-4 family residential real estate | Numerical risk rating (1-4)
Composition Of Loan Portfolio [Line Items]
Loans receivable, net of nonaccretable differences and allowances for covered loan losses	6,086,210		7,392,585
Covered loans | 1-4 family residential real estate | Numerical risk rating (5)
Composition Of Loan Portfolio [Line Items]
Loans receivable, net of nonaccretable differences and allowances for covered loan losses	63,123		693,038
Covered loans | 1-4 family residential real estate | Numerical risk rating (6)
Composition Of Loan Portfolio [Line Items]
Loans receivable, net of nonaccretable differences and allowances for covered loan losses	1,305,264		2,591,713
Covered loans | 1-4 family residential real estate | Numerical risk rating (7)
Composition Of Loan Portfolio [Line Items]
Loans receivable, net of nonaccretable differences and allowances for covered loan losses	0		0
Covered loans | 1-4 family residential real estate | Numerical risk rating (8)
Composition Of Loan Portfolio [Line Items]
Loans receivable, net of nonaccretable differences and allowances for covered loan losses	0		0
Covered loans | Commercial real estate
Composition Of Loan Portfolio [Line Items]
Loans receivable, net of nonaccretable differences and allowances for covered loan losses	44,112,157		61,299,587
Covered loans | Commercial real estate | Numerical risk rating (1-4)
Composition Of Loan Portfolio [Line Items]
Loans receivable, net of nonaccretable differences and allowances for covered loan losses	23,739,341		34,017,713
Covered loans | Commercial real estate | Numerical risk rating (5)
Composition Of Loan Portfolio [Line Items]
Loans receivable, net of nonaccretable differences and allowances for covered loan losses	6,403,968		8,411,973
Covered loans | Commercial real estate | Numerical risk rating (6)
Composition Of Loan Portfolio [Line Items]
Loans receivable, net of nonaccretable differences and allowances for covered loan losses	13,968,848		18,869,901
Covered loans | Commercial real estate | Numerical risk rating (7)
Composition Of Loan Portfolio [Line Items]
Loans receivable, net of nonaccretable differences and allowances for covered loan losses	0		0
Covered loans | Commercial real estate | Numerical risk rating (8)
Composition Of Loan Portfolio [Line Items]
Loans receivable, net of nonaccretable differences and allowances for covered loan losses	0		0
Covered loans | Commercial
Composition Of Loan Portfolio [Line Items]
Loans receivable, net of nonaccretable differences and allowances for covered loan losses	1,814,638		3,512,879
Covered loans | Commercial | Numerical risk rating (1-4)
Composition Of Loan Portfolio [Line Items]
Loans receivable, net of nonaccretable differences and allowances for covered loan losses	1,483,044		1,982,382
Covered loans | Commercial | Numerical risk rating (5)
Composition Of Loan Portfolio [Line Items]
Loans receivable, net of nonaccretable differences and allowances for covered loan losses	0		448,957
Covered loans | Commercial | Numerical risk rating (6)
Composition Of Loan Portfolio [Line Items]
Loans receivable, net of nonaccretable differences and allowances for covered loan losses	331,594		1,081,540
Covered loans | Commercial | Numerical risk rating (7)
Composition Of Loan Portfolio [Line Items]
Loans receivable, net of nonaccretable differences and allowances for covered loan losses	0		0
Covered loans | Commercial | Numerical risk rating (8)
Composition Of Loan Portfolio [Line Items]
Loans receivable, net of nonaccretable differences and allowances for covered loan losses	0		0
Covered loans | Real estate construction
Composition Of Loan Portfolio [Line Items]
Loans receivable, net of nonaccretable differences and allowances for covered loan losses	0		0
Covered loans | Real estate construction | Numerical risk rating (1-4)
Composition Of Loan Portfolio [Line Items]
Loans receivable, net of nonaccretable differences and allowances for covered loan losses	0		0
Covered loans | Real estate construction | Numerical risk rating (5)
Composition Of Loan Portfolio [Line Items]
Loans receivable, net of nonaccretable differences and allowances for covered loan losses	0		0
Covered loans | Real estate construction | Numerical risk rating (6)
Composition Of Loan Portfolio [Line Items]
Loans receivable, net of nonaccretable differences and allowances for covered loan losses	0		0
Covered loans | Real estate construction | Numerical risk rating (7)
Composition Of Loan Portfolio [Line Items]
Loans receivable, net of nonaccretable differences and allowances for covered loan losses	0		0
Covered loans | Real estate construction | Numerical risk rating (8)
Composition Of Loan Portfolio [Line Items]
Loans receivable, net of nonaccretable differences and allowances for covered loan losses	0		0
Covered loans | Consumer and other
Composition Of Loan Portfolio [Line Items]
Loans receivable, net of nonaccretable differences and allowances for covered loan losses	41,725		148,098
Covered loans | Consumer and other | Numerical risk rating (1-4)
Composition Of Loan Portfolio [Line Items]
Loans receivable, net of nonaccretable differences and allowances for covered loan losses	41,725		74,392
Covered loans | Consumer and other | Numerical risk rating (5)
Composition Of Loan Portfolio [Line Items]
Loans receivable, net of nonaccretable differences and allowances for covered loan losses	0		0
Covered loans | Consumer and other | Numerical risk rating (6)
Composition Of Loan Portfolio [Line Items]
Loans receivable, net of nonaccretable differences and allowances for covered loan losses	0		73,706
Covered loans | Consumer and other | Numerical risk rating (7)
Composition Of Loan Portfolio [Line Items]
Loans receivable, net of nonaccretable differences and allowances for covered loan losses	0		0
Covered loans | Consumer and other | Numerical risk rating (8)
Composition Of Loan Portfolio [Line Items]
Loans receivable, net of nonaccretable differences and allowances for covered loan losses	$ 0		$ 0