Accounting for Certain Loans Acquired in a Purchase - Accretable Yield or Income Expected to be Collected (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Accretable Yield Movement Schedule [Roll Forward]
Beginning balance	$ 3,083	$ 5,299	$ 3,951	$ 5,612
Additions	667		667
Accretion	(1,158)	(2,115)	(4,396)	(3,611)
Reclassification from nonaccretable	682	1,686	3,052	2,869
Disposals	(667)	(243)	(667)	(243)
Ending balance	2,607	4,627	2,607	4,627
Arlington Bank
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Accretable Yield Movement Schedule [Roll Forward]
Beginning balance
Additions	667		667
Accretion
Reclassification from nonaccretable
Disposals
Ending balance	667		667
Ameriana
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Accretable Yield Movement Schedule [Roll Forward]
Beginning balance	824	2,120	1,630	2,160
Additions
Accretion	(156)	(47)	(2,658)	(87)
Reclassification from nonaccretable	3	5	1,699	5
Disposals		(232)		(232)
Ending balance	671	1,846	671	1,846
C Financial
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Accretable Yield Movement Schedule [Roll Forward]
Beginning balance	68	100	73	114
Additions
Accretion	(48)	(71)	(88)	(86)
Reclassification from nonaccretable	43	52	78	53
Disposals
Ending balance	63	81	63	81
Community
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Accretable Yield Movement Schedule [Roll Forward]
Beginning balance	1,202	1,456	1,233	1,508
Additions
Accretion	(371)	(849)	(433)	(912)
Reclassification from nonaccretable	181	738	212	749
Disposals	(122)		(122)
Ending balance	890	1,345	890	1,345
CFS
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Accretable Yield Movement Schedule [Roll Forward]
Beginning balance	732	1,033	736	1,188
Additions
Accretion	(417)	(855)	(887)	(2,145)
Reclassification from nonaccretable	311	737	777	1,872
Disposals	(545)	(11)	(545)	(11)
Ending balance	81	904	81	904
SCB
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Accretable Yield Movement Schedule [Roll Forward]
Beginning balance	257	590	279	642
Additions
Accretion	(166)	(293)	(330)	(381)
Reclassification from nonaccretable	144	154	286	190
Disposals
Ending balance	$ 235	$ 451	$ 235	$ 451

Amount of the excess of a loan's cash flows expected to be collected over the investor's initial investment in acquired loans not accounted for as debt securities with evidence of deterioration of credit quality.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 30
-Section 50
-Paragraph 2
-Subparagraph (a)(2)
-URI http://asc.fasb.org/extlink&oid=82894903&loc=d3e15032-111544

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 30
-Section 15
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=82894507&loc=d3e13503-111538

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- Definition

Amount of accretion recognized for the excess of a loan's cash flows expected to be collected over the investor's initial investment in acquired loans not accounted for as debt securities, with evidence of deterioration of credit quality.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 30
-Section 15
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=82894507&loc=d3e13503-111538

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 30
-Section 50
-Paragraph 2
-Subparagraph (a)(2)
-URI http://asc.fasb.org/extlink&oid=82894903&loc=d3e15032-111544

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- Definition

Amount of additions to the excess of a loan's cash flows expected to be collected over the investor's initial investment in acquired loans not accounted for as debt securities with evidence of deterioration of credit quality.

+ References

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- Definition

Amount of reduction, resulting from a sale or transfer of a loan, in the excess of a loan's cash flows expected to be collected over the investor's initial investment in acquired loans not accounted for as debt securities with evidence of deterioration of credit quality.

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- Definition

A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

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Amount of increase of reclassification from nonaccretable difference to the excess of a loan's cash flows expected to be collected over the investor's initial investment in acquired loans not accounted for as debt securities with evidence of deterioration of credit quality.

+ References

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