Accounting for Certain Loans Acquired in a Purchase - Carrying Amount of Loans Included in Balance Sheet (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Accounts, Notes, Loans and Financing Receivable [Line Items]
Outstanding Balance	$ 698,097	$ 961,382
Carrying Amount	665,417	917,589
Allowance	380	153
Carrying Amount Net of Allowance	665,037	917,436
Ameriana
Accounts, Notes, Loans and Financing Receivable [Line Items]
Outstanding Balance	250,824	330,918
Carrying Amount	240,053	319,664
Allowance	265
Carrying Amount Net of Allowance	239,788	319,664
C Financial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Outstanding Balance	77,100	99,166
Carrying Amount	75,194	96,829
Carrying Amount Net of Allowance	75,194	96,829
Community
Accounts, Notes, Loans and Financing Receivable [Line Items]
Outstanding Balance	60,108	99,541
Carrying Amount	56,007	93,355
Allowance	23	4
Carrying Amount Net of Allowance	55,984	93,351
CFS
Accounts, Notes, Loans and Financing Receivable [Line Items]
Outstanding Balance	279,479	393,014
Carrying Amount	266,845	373,649
Allowance	92	149
Carrying Amount Net of Allowance	266,753	373,500
SCB
Accounts, Notes, Loans and Financing Receivable [Line Items]
Outstanding Balance	30,586	38,743
Carrying Amount	27,318	34,092
Carrying Amount Net of Allowance	27,318	34,092
Commercial and industrial loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Outstanding Balance	37,236	85,441
Commercial and industrial loans | Ameriana
Accounts, Notes, Loans and Financing Receivable [Line Items]
Outstanding Balance	8,003	21,888
Commercial and industrial loans | C Financial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Outstanding Balance	85	104
Commercial and industrial loans | Community
Accounts, Notes, Loans and Financing Receivable [Line Items]
Outstanding Balance	2,269	6,769
Commercial and industrial loans | CFS
Accounts, Notes, Loans and Financing Receivable [Line Items]
Outstanding Balance	23,327	52,060
Commercial and industrial loans | SCB
Accounts, Notes, Loans and Financing Receivable [Line Items]
Outstanding Balance	3,552	4,620
Agriculture production financing and other loans to farmers
Accounts, Notes, Loans and Financing Receivable [Line Items]
Outstanding Balance	2,710	3,049
Agriculture production financing and other loans to farmers | Community
Accounts, Notes, Loans and Financing Receivable [Line Items]
Outstanding Balance	1,030	1,761
Agriculture production financing and other loans to farmers | CFS
Accounts, Notes, Loans and Financing Receivable [Line Items]
Outstanding Balance	50
Agriculture production financing and other loans to farmers | SCB
Accounts, Notes, Loans and Financing Receivable [Line Items]
Outstanding Balance	1,630	1,288
Construction
Accounts, Notes, Loans and Financing Receivable [Line Items]
Outstanding Balance	29,298	40,991
Construction | Ameriana
Accounts, Notes, Loans and Financing Receivable [Line Items]
Outstanding Balance	22,017	23,365
Construction | C Financial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Outstanding Balance	2,835	6,214
Construction | Community
Accounts, Notes, Loans and Financing Receivable [Line Items]
Outstanding Balance	4,026	10,436
Construction | CFS
Accounts, Notes, Loans and Financing Receivable [Line Items]
Outstanding Balance	420	976
Commercial and farmland
Accounts, Notes, Loans and Financing Receivable [Line Items]
Outstanding Balance	303,362	425,014
Commercial and farmland | Ameriana
Accounts, Notes, Loans and Financing Receivable [Line Items]
Outstanding Balance	103,075	144,514
Commercial and farmland | C Financial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Outstanding Balance	22,130	27,838
Commercial and farmland | Community
Accounts, Notes, Loans and Financing Receivable [Line Items]
Outstanding Balance	36,947	49,997
Commercial and farmland | CFS
Accounts, Notes, Loans and Financing Receivable [Line Items]
Outstanding Balance	131,895	189,372
Commercial and farmland | SCB
Accounts, Notes, Loans and Financing Receivable [Line Items]
Outstanding Balance	9,315	13,293
Residential
Accounts, Notes, Loans and Financing Receivable [Line Items]
Outstanding Balance	257,640	325,141
Residential | Ameriana
Accounts, Notes, Loans and Financing Receivable [Line Items]
Outstanding Balance	103,414	123,231
Residential | C Financial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Outstanding Balance	44,101	55,856
Residential | Community
Accounts, Notes, Loans and Financing Receivable [Line Items]
Outstanding Balance	9,363	21,886
Residential | CFS
Accounts, Notes, Loans and Financing Receivable [Line Items]
Outstanding Balance	96,627	118,105
Residential | SCB
Accounts, Notes, Loans and Financing Receivable [Line Items]
Outstanding Balance	4,135	6,063
Home equity
Accounts, Notes, Loans and Financing Receivable [Line Items]
Outstanding Balance	64,819	77,053
Home equity | Ameriana
Accounts, Notes, Loans and Financing Receivable [Line Items]
Outstanding Balance	11,728	14,261
Home equity | C Financial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Outstanding Balance	7,947	9,144
Home equity | Community
Accounts, Notes, Loans and Financing Receivable [Line Items]
Outstanding Balance	6,326	8,231
Home equity | CFS
Accounts, Notes, Loans and Financing Receivable [Line Items]
Outstanding Balance	26,894	31,986
Home equity | SCB
Accounts, Notes, Loans and Financing Receivable [Line Items]
Outstanding Balance	11,924	13,431
Individuals' loans for household and other personal expenditures
Accounts, Notes, Loans and Financing Receivable [Line Items]
Outstanding Balance	1,142	2,693
Individuals' loans for household and other personal expenditures | Ameriana
Accounts, Notes, Loans and Financing Receivable [Line Items]
Outstanding Balance	762	1,731
Individuals' loans for household and other personal expenditures | C Financial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Outstanding Balance	2	10
Individuals' loans for household and other personal expenditures | Community
Accounts, Notes, Loans and Financing Receivable [Line Items]
Outstanding Balance	147	461
Individuals' loans for household and other personal expenditures | CFS
Accounts, Notes, Loans and Financing Receivable [Line Items]
Outstanding Balance	201	443
Individuals' loans for household and other personal expenditures | SCB
Accounts, Notes, Loans and Financing Receivable [Line Items]
Outstanding Balance	30	48
Other commercial loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Outstanding Balance	1,890	2,000
Other commercial loans | Ameriana
Accounts, Notes, Loans and Financing Receivable [Line Items]
Outstanding Balance	1,825	1,928
Other commercial loans | CFS
Accounts, Notes, Loans and Financing Receivable [Line Items]
Outstanding Balance	$ 65	$ 72