Loans Receivable - Summary of Non-Covered Loans Receivable (Details) (USD $)	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013
Loans not covered by loss sharing agreements:
Loans receivable, net of undisbursed proceeds of loans in process	$ 656,212,122		$ 606,366,713
Total loans not covered, net	607,118,216		536,732,494
Non-covered loans
Loans not covered by loss sharing agreements:
Loans receivable, net of undisbursed proceeds of loans in process	617,053,035		546,570,720	491,481,394
Unamortized loan origination fees, net	1,471,715		1,364,853
Allowance for loan losses	8,463,104	8,494,197	8,473,373	8,430,617	8,494,412	8,188,896
Non-covered loans | 1-4 family residential real estate
Loans not covered by loss sharing agreements:
Loans receivable, net of undisbursed proceeds of loans in process	172,131,248		152,810,501	135,181,013
Allowance for loan losses	625,506	810,797	812,130	671,496	739,764	862,043
Non-covered loans | Commercial real estate
Loans not covered by loss sharing agreements:
Loans receivable, net of undisbursed proceeds of loans in process	340,171,680		300,556,023	271,156,431
Allowance for loan losses	6,071,131	5,887,208	5,969,819	6,498,419	6,002,964	5,446,357
Non-covered loans | Commercial
Loans not covered by loss sharing agreements:
Loans receivable, net of undisbursed proceeds of loans in process	29,431,806		24,759,682	21,500,766
Allowance for loan losses	397,611	391,617	400,883	441,323	684,585	455,833
Non-covered loans | Real estate construction
Loans not covered by loss sharing agreements:
Loans receivable, net of undisbursed proceeds of loans in process	70,758,469		63,485,411	47,111,623
Allowance for loan losses	419,981	470,369	492,903	405,500	362,591	387,302
Non-covered loans | Consumer and other
Loans not covered by loss sharing agreements:
Loans receivable, net of undisbursed proceeds of loans in process	4,559,832		4,959,103	16,531,561
Allowance for loan losses	$ 14,019	$ 14,144	$ 13,990	$ 51,580	$ 54,067	$ 124,717