Loans - Schedule of Loans Renegotiated in Troubled Debt Restructurings (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013 notes	Dec. 31, 2012 notes	Dec. 31, 2011 notes
Loans and Leases Receivable, Troubled Debt Restructuring
Financing Receivables, Impaired, Troubled Debt Restructuring, Write-down	$ 0	$ 0	$ 0
Loans renegotiated in troubled debt restructurings	59,792	76,597
Loans renegotiated in troubled debt restructurings, non-accrual loans	38,011	44,665
Loans tenegotiated in troubled debt restructurings, accrual loans	21,781	31,932
Financing receivable, modifications, subsequent default, number of contracts, during period	43	38	137
Principle balance at restructure date	28,403	22,760	85,143
Interest only period
Loans and Leases Receivable, Troubled Debt Restructuring
Principle balance at restructure date	1,684	955	57,835
Extension of terms or maturity
Loans and Leases Receivable, Troubled Debt Restructuring
Principle balance at restructure date	9,980	2,704	10,790
Interest rate adjustment
Loans and Leases Receivable, Troubled Debt Restructuring
Principle balance at restructure date	14,263	6,494	5,119
Other
Loans and Leases Receivable, Troubled Debt Restructuring
Principle balance at restructure date	2,476	12,607	11,399
Commercial real estate
Loans and Leases Receivable, Troubled Debt Restructuring
Financing receivable, modifications, subsequent default, number of contracts, during period	19	16	60
Principle balance at restructure date	15,651	14,074	38,921
Commercial real estate | Interest only period
Loans and Leases Receivable, Troubled Debt Restructuring
Principle balance at restructure date	543	0	23,982
Commercial real estate | Extension of terms or maturity
Loans and Leases Receivable, Troubled Debt Restructuring
Principle balance at restructure date	1,378	959	4,444
Commercial real estate | Interest rate adjustment
Loans and Leases Receivable, Troubled Debt Restructuring
Principle balance at restructure date	11,420	4,504	3,131
Commercial real estate | Other
Loans and Leases Receivable, Troubled Debt Restructuring
Principle balance at restructure date	2,310	8,611	7,364
Commercial construction real estate
Loans and Leases Receivable, Troubled Debt Restructuring
Financing receivable, modifications, subsequent default, number of contracts, during period		1
Principle balance at restructure date		3,155
Commercial construction real estate | Interest only period
Loans and Leases Receivable, Troubled Debt Restructuring
Principle balance at restructure date		0
Commercial construction real estate | Extension of terms or maturity
Loans and Leases Receivable, Troubled Debt Restructuring
Principle balance at restructure date		0
Commercial construction real estate | Interest rate adjustment
Loans and Leases Receivable, Troubled Debt Restructuring
Principle balance at restructure date		0
Commercial construction real estate | Other
Loans and Leases Receivable, Troubled Debt Restructuring
Principle balance at restructure date		3,155
Land acquisition & development construction real estate
Loans and Leases Receivable, Troubled Debt Restructuring
Financing receivable, modifications, subsequent default, number of contracts, during period	8	5	9
Principle balance at restructure date	9,788	3,380	6,207
Land acquisition & development construction real estate | Interest only period
Loans and Leases Receivable, Troubled Debt Restructuring
Principle balance at restructure date	528	0	995
Land acquisition & development construction real estate | Extension of terms or maturity
Loans and Leases Receivable, Troubled Debt Restructuring
Principle balance at restructure date	7,308	1,000	4,124
Land acquisition & development construction real estate | Interest rate adjustment
Loans and Leases Receivable, Troubled Debt Restructuring
Principle balance at restructure date	1,952	1,757	680
Land acquisition & development construction real estate | Other
Loans and Leases Receivable, Troubled Debt Restructuring
Principle balance at restructure date	0	623	408
Residential construction real estate
Loans and Leases Receivable, Troubled Debt Restructuring
Financing receivable, modifications, subsequent default, number of contracts, during period	3	2	5
Principle balance at restructure date	819	513	8,861
Residential construction real estate | Interest only period
Loans and Leases Receivable, Troubled Debt Restructuring
Principle balance at restructure date	0	0	7,749
Residential construction real estate | Extension of terms or maturity
Loans and Leases Receivable, Troubled Debt Restructuring
Principle balance at restructure date	408	280	878
Residential construction real estate | Interest rate adjustment
Loans and Leases Receivable, Troubled Debt Restructuring
Principle balance at restructure date	411	233	234
Residential construction real estate | Other
Loans and Leases Receivable, Troubled Debt Restructuring
Principle balance at restructure date	0	0	0
Total construction loans
Loans and Leases Receivable, Troubled Debt Restructuring
Financing receivable, modifications, subsequent default, number of contracts, during period	11	8	14
Principle balance at restructure date	10,607	7,048	15,068
Total construction loans | Interest only period
Loans and Leases Receivable, Troubled Debt Restructuring
Principle balance at restructure date	528	0	8,744
Total construction loans | Extension of terms or maturity
Loans and Leases Receivable, Troubled Debt Restructuring
Principle balance at restructure date	7,716	1,280	5,002
Total construction loans | Interest rate adjustment
Loans and Leases Receivable, Troubled Debt Restructuring
Principle balance at restructure date	2,363	1,990	914
Total construction loans | Other
Loans and Leases Receivable, Troubled Debt Restructuring
Principle balance at restructure date	0	3,778	408
Residential real estate
Loans and Leases Receivable, Troubled Debt Restructuring
Financing receivable, modifications, subsequent default, number of contracts, during period	5	2	6
Principle balance at restructure date	787	593	10,948
Residential real estate | Interest only period
Loans and Leases Receivable, Troubled Debt Restructuring
Principle balance at restructure date	0	568	9,771
Residential real estate | Extension of terms or maturity
Loans and Leases Receivable, Troubled Debt Restructuring
Principle balance at restructure date	708	25	364
Residential real estate | Interest rate adjustment
Loans and Leases Receivable, Troubled Debt Restructuring
Principle balance at restructure date	0	0	223
Residential real estate | Other
Loans and Leases Receivable, Troubled Debt Restructuring
Principle balance at restructure date	79	0	590
Agricultural real estate
Loans and Leases Receivable, Troubled Debt Restructuring
Financing receivable, modifications, subsequent default, number of contracts, during period	1	1	7
Principle balance at restructure date	188	154	4,540
Agricultural real estate | Interest only period
Loans and Leases Receivable, Troubled Debt Restructuring
Principle balance at restructure date	0	0	3,594
Agricultural real estate | Extension of terms or maturity
Loans and Leases Receivable, Troubled Debt Restructuring
Principle balance at restructure date	0	154	517
Agricultural real estate | Interest rate adjustment
Loans and Leases Receivable, Troubled Debt Restructuring
Principle balance at restructure date	188	0	189
Agricultural real estate | Other
Loans and Leases Receivable, Troubled Debt Restructuring
Principle balance at restructure date	0	0	240
Total real estate loans
Loans and Leases Receivable, Troubled Debt Restructuring
Financing receivable, modifications, subsequent default, number of contracts, during period	36	27	87
Principle balance at restructure date	27,233	21,869	69,477
Total real estate loans | Interest only period
Loans and Leases Receivable, Troubled Debt Restructuring
Principle balance at restructure date	1,071	568	46,091
Total real estate loans | Extension of terms or maturity
Loans and Leases Receivable, Troubled Debt Restructuring
Principle balance at restructure date	9,802	2,418	10,327
Total real estate loans | Interest rate adjustment
Loans and Leases Receivable, Troubled Debt Restructuring
Principle balance at restructure date	13,971	6,494	4,457
Total real estate loans | Other
Loans and Leases Receivable, Troubled Debt Restructuring
Principle balance at restructure date	2,389	12,389	8,602
Indirect consumer
Loans and Leases Receivable, Troubled Debt Restructuring
Financing receivable, modifications, subsequent default, number of contracts, during period			2
Principle balance at restructure date			29
Indirect consumer | Interest only period
Loans and Leases Receivable, Troubled Debt Restructuring
Principle balance at restructure date			0
Indirect consumer | Extension of terms or maturity
Loans and Leases Receivable, Troubled Debt Restructuring
Principle balance at restructure date			0
Indirect consumer | Interest rate adjustment
Loans and Leases Receivable, Troubled Debt Restructuring
Principle balance at restructure date			0
Indirect consumer | Other
Loans and Leases Receivable, Troubled Debt Restructuring
Principle balance at restructure date			29
Other consumer
Loans and Leases Receivable, Troubled Debt Restructuring
Financing receivable, modifications, subsequent default, number of contracts, during period	1	1	3
Principle balance at restructure date	27	69	78
Other consumer | Interest only period
Loans and Leases Receivable, Troubled Debt Restructuring
Principle balance at restructure date	0	0	17
Other consumer | Extension of terms or maturity
Loans and Leases Receivable, Troubled Debt Restructuring
Principle balance at restructure date	0	69	11
Other consumer | Interest rate adjustment
Loans and Leases Receivable, Troubled Debt Restructuring
Principle balance at restructure date	27	0	0
Other consumer | Other
Loans and Leases Receivable, Troubled Debt Restructuring
Principle balance at restructure date	0	0	50
Total consumer loans
Loans and Leases Receivable, Troubled Debt Restructuring
Financing receivable, modifications, subsequent default, number of contracts, during period			5
Principle balance at restructure date			107
Total consumer loans | Interest only period
Loans and Leases Receivable, Troubled Debt Restructuring
Principle balance at restructure date			17
Total consumer loans | Extension of terms or maturity
Loans and Leases Receivable, Troubled Debt Restructuring
Principle balance at restructure date			11
Total consumer loans | Interest rate adjustment
Loans and Leases Receivable, Troubled Debt Restructuring
Principle balance at restructure date			0
Total consumer loans | Other
Loans and Leases Receivable, Troubled Debt Restructuring
Principle balance at restructure date			79
Commercial
Loans and Leases Receivable, Troubled Debt Restructuring
Financing receivable, modifications, subsequent default, number of contracts, during period	6	10	40
Principle balance at restructure date	1,143	822	15,372
Commercial | Interest only period
Loans and Leases Receivable, Troubled Debt Restructuring
Principle balance at restructure date	613	387	11,727
Commercial | Extension of terms or maturity
Loans and Leases Receivable, Troubled Debt Restructuring
Principle balance at restructure date	178	217	428
Commercial | Interest rate adjustment
Loans and Leases Receivable, Troubled Debt Restructuring
Principle balance at restructure date	265	0	662
Commercial | Other
Loans and Leases Receivable, Troubled Debt Restructuring
Principle balance at restructure date	87	218	2,555
Agricultural
Loans and Leases Receivable, Troubled Debt Restructuring
Financing receivable, modifications, subsequent default, number of contracts, during period			5
Principle balance at restructure date			187
Agricultural | Interest only period
Loans and Leases Receivable, Troubled Debt Restructuring
Principle balance at restructure date			0
Agricultural | Extension of terms or maturity
Loans and Leases Receivable, Troubled Debt Restructuring
Principle balance at restructure date			24
Agricultural | Interest rate adjustment
Loans and Leases Receivable, Troubled Debt Restructuring
Principle balance at restructure date			0
Agricultural | Other
Loans and Leases Receivable, Troubled Debt Restructuring
Principle balance at restructure date			$ 163