Loans and Leases (Loans and Leases Receivable) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
Dec. 31, 2014	Dec. 31, 2013
Loans and Leases [Line Items]
Loans and leases receivable held to maturity	$ 3,877,863us-gaap_NotesReceivableGross	$ 3,500,109us-gaap_NotesReceivableGross
Gross loans and leases receivable held to maturity	3,877,863	3,500,109
Unearned discount	(90)	(168)
Deferred loan fees	(1,028)	(2,989)
Total net loans and leases receivable held to maturity	3,876,745	3,496,952
Loans covered under loss share agreement	1,258	5,749
Allowance for loan and lease losses	(41,449)	(41,685)
Loans and leases receivable, net	3,836,554	3,461,016
Threshold period past due, nonperforming status of loans and leases	90 days
Commercial
Loans and Leases [Line Items]
Loans and leases receivable held to maturity	1,036,080	950,197
Commercial Real Estate
Loans and Leases [Line Items]
Loans and leases receivable held to maturity	1,707,060	1,529,683
Agricultural and Agricultural Real Estate
Loans and Leases [Line Items]
Loans and leases receivable held to maturity	423,827	376,735
Loans covered under loss share agreement	0	543
Residential Real Estate
Loans and Leases [Line Items]
Loans and leases receivable held to maturity	380,341	349,349
Loans covered under loss share agreement	1,204	2,280
Consumer
Loans and Leases [Line Items]
Loans and leases receivable held to maturity	330,555	294,145
Loans covered under loss share agreement	0	612
Commercial and Commercial Real Estate
Loans and Leases [Line Items]
Loans and leases receivable held to maturity	2,743,140	2,479,880
Loans covered under loss share agreement	$ 54	$ 2,314
Citizens Finance Co \| Loans and Finance Receivables \| Consumer
Loans and Leases [Line Items]
Concentration risk, percentage	21.00%
Minimum \| Residential Real Estate
Loans and Leases [Line Items]
Length of loan agreements	10 years
Minimum \| Commercial and Commercial Real Estate
Loans and Leases [Line Items]
Length of loan agreements	1 year
Maximum \| Residential Real Estate
Loans and Leases [Line Items]
Length of loan agreements	30 years
Maximum \| Commercial and Commercial Real Estate
Loans and Leases [Line Items]
Length of loan agreements	5 years

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Loans and Leases Receivable, Contract Term

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- Definition

Threshold Period Past Due for Nonperforming Status of Financing Receivable

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- Definition

For an entity that discloses a concentration risk in relation to quantitative amount, which serves as the "benchmark" (or denominator) in the equation, this concept represents the concentration percentage derived from the division.

+ References

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-Publisher FASB

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Amount of allowance to cover probable credit losses on loans and leases. Includes carryover of or adjustments to the allowance for loan losses in connection with business combinations. Excludes allowance for loans and leases covered under loss sharing agreements.

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-Number Topic 6

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Amount of deferred interest and fee income, unamortized costs incurred to originate loans and leases, unamortized loan commitments and loan syndication fees, and premiums over or discounts from face amounts of acquired loans. Excludes amounts for loans and leases covered under loss sharing agreements.

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Amount before allowance of loans and leases held in portfolio, including but not limited to, commercial and consumer loans. Includes deferred interest and fees, undisbursed portion of loan balance, unamortized costs and premiums and discounts from face amounts. Excludes loans and leases covered under loss sharing agreements.

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- Definition

Aggregate gross carrying amount of loans and leases receivable covered by loss sharing agreements.

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- Definition

Amount before allowance and after deduction of deferred interest and fees, unamortized costs and premiums and discounts from face amounts, of loans and leases held in portfolio, including but not limited to, commercial and consumer loans. Excludes loans and leases covered under loss sharing agreements.

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Amount after allowance and deduction of deferred interest and fees, unamortized costs and premiums over and discounts from face amounts, of loans and leases held in portfolio, including but not limited to, commercial and consumer loans. Includes loans and leases covered under loss sharing agreements.

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- Definition

Amount representing an agreement for an unconditional promise by the maker to pay the entity (holder) a definite sum of money at a future date. Such amount may include accrued interest receivable in accordance with the terms of the note. The note also may contain provisions and related items including a discount or premium, payable on demand, secured, or unsecured, interest bearing or noninterest bearing, among a myriad of other features and characteristics. Excludes amounts related to receivables held-for-sale.

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Amount of deferred fees paid by borrowers and unamortized costs incurred to originate loans and leases, unamortized loan commitments and loan syndication fees, and premiums over or discounts from face amounts of loans that are being amortized into income as an adjustment to yield. Excludes amounts for loans and leases covered under loss sharing agreements.

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