Loans - Impaired Loans - Average Recorded Investment and Interest Income Recognized (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Average Recorded Investment
With no related allowance recorded	$ 35,043	$ 47,877	$ 68,403
With an allowance recorded	6,185	19,901	45,402
Total impaired loans	41,228	67,778	113,805
Interest Income Recognized
With no related allowance recorded	467	390	642
With an allowance recorded	1		40
Total impaired loans	468	390	682
Commercial
Average Recorded Investment
With no related allowance recorded	764	112	354
With an allowance recorded		283	610
Real estate - commercial \| Owner occupied general purpose
Average Recorded Investment
With no related allowance recorded	4,834	3,508	4,616
With an allowance recorded	365	872	4,499
Interest Income Recognized
With no related allowance recorded	104	3
Real estate - commercial \| Owner occupied special purpose
Average Recorded Investment
With no related allowance recorded	2,584	5,275	9,893
With an allowance recorded	2,150	4,277	4,106
Interest Income Recognized
With no related allowance recorded	45
Real estate - commercial \| Non-owner occupied general purpose
Average Recorded Investment
With no related allowance recorded	5,130	9,892	11,329
With an allowance recorded	508	1,859	5,588
Interest Income Recognized
With no related allowance recorded		75	270
Real estate - commercial \| Non-owner occupied special purpose
Average Recorded Investment
With no related allowance recorded	1,042	569	928
With an allowance recorded			217
Real estate - commercial \| Retail properties
Average Recorded Investment
With no related allowance recorded	1,572	5,962	6,683
With an allowance recorded		876	6,531
Real estate - commercial \| Farm
Average Recorded Investment
With no related allowance recorded		1,259	1,798
With an allowance recorded			248
Real estate - construction \| Homebuilder
Average Recorded Investment
With no related allowance recorded	1,903	3,085	7,413
With an allowance recorded	84	97	1,115
Interest Income Recognized
With no related allowance recorded	82	97	119
Real estate - construction \| Land
Average Recorded Investment
With no related allowance recorded	105	232	1,140
Real estate - construction \| Commercial speculative
Average Recorded Investment
With no related allowance recorded	369	1,501	5,907
With an allowance recorded	587	2,748	4,495
Real estate - construction \| All other
Average Recorded Investment
With no related allowance recorded	147	41	2,193
With an allowance recorded	353	458	430
Real estate - residential \| Investor
Average Recorded Investment
With no related allowance recorded	4,290	5,576	4,075
With an allowance recorded	410	2,713	8,514
Interest Income Recognized
With no related allowance recorded	43
Real estate - residential \| Owner occupied
Average Recorded Investment
With no related allowance recorded	10,299	9,284	10,635
With an allowance recorded	794	3,737	7,141
Interest Income Recognized
With no related allowance recorded	187	209	249
With an allowance recorded	1		40
Real estate - residential \| Revolving and junior liens
Average Recorded Investment
With no related allowance recorded	2,004	1,570	1,428
With an allowance recorded	934	1,981	1,908
Interest Income Recognized
With no related allowance recorded	6	6	4
Consumer
Average Recorded Investment
With no related allowance recorded		$ 11	$ 11

Average amount of investment of impaired financing receivables with related allowance for credit losses and without a related allowance for credit losses.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 310

-SubTopic 10

-Section 50

-Paragraph 15

-Subparagraph (c)(1)

-URI http://asc.fasb.org/extlink&oid=35738203&loc=d3e5212-111524

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 310

-SubTopic 10

-Section 50

-Paragraph 17

-URI http://asc.fasb.org/extlink&oid=35738203&loc=d3e5258-111524

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