Loans and Leases (Impaired loans not covered by loss share agreements) (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2016	Dec. 31, 2015
Impaired Financing Receivable, Unpaid Principal Balance [Abstract]
Impaired loans with a related allowance, Unpaid Contractual Balance	$ 15,189	$ 9,210
Impaired loans without a related allowance, Unpaid Contractual Balance	82,343	74,644
Total impaired loans held to maturity, Unpaid Contractual Balance	97,532	83,854
Impaired Financing Receivable, Recorded Investment [Abstract]
Impaired loans with a related allowance, Loan Balance	15,100	9,093
Impaired loans without a related allowance, Loan Balance	78,901	71,128
Total impaired loans held to maturity, Loan Balance	94,001	80,221
Impaired loans, Related Allowance Recorded	3,794	2,768
Impaired Financing Receivable, Average Recorded Investment [Abstract]
Impaired loans with a related allowance, Avg. Loan Balance	12,472	11,287
Impaired loans without a related allowance, Avg. Loan Balance	84,286	60,831
Total impaired loans held to maturity, Avg. Loan Balance	96,758	72,118
Impaired Financing Receivable, Interest Income, Accrual Method [Abstract]
Impaired loans with a related allowance, Interest Income Recognized	73	80
Impaired loans without a related allowance, Interest Income Recognized	819	2,268
Total impaired loans held to maturity, Interest Income Recognized	892	2,348
Commercial
Impaired Financing Receivable, Unpaid Principal Balance [Abstract]
Impaired loans with a related allowance, Unpaid Contractual Balance	4,766	1,192
Impaired loans without a related allowance, Unpaid Contractual Balance	6,277	5,784
Total impaired loans held to maturity, Unpaid Contractual Balance	11,043	6,976
Impaired Financing Receivable, Recorded Investment [Abstract]
Impaired loans with a related allowance, Loan Balance	4,766	1,160
Impaired loans without a related allowance, Loan Balance	6,252	5,759
Total impaired loans held to maturity, Loan Balance	11,018	6,919
Impaired loans, Related Allowance Recorded	984	471
Impaired Financing Receivable, Average Recorded Investment [Abstract]
Impaired loans with a related allowance, Avg. Loan Balance	2,137	524
Impaired loans without a related allowance, Avg. Loan Balance	9,849	7,511
Total impaired loans held to maturity, Avg. Loan Balance	11,986	8,035
Impaired Financing Receivable, Interest Income, Accrual Method [Abstract]
Impaired loans with a related allowance, Interest Income Recognized	35	12
Impaired loans without a related allowance, Interest Income Recognized	143	515
Total impaired loans held to maturity, Interest Income Recognized	178	527
Commercial real estate
Impaired Financing Receivable, Unpaid Principal Balance [Abstract]
Impaired loans with a related allowance, Unpaid Contractual Balance	4,297	2,697
Impaired loans without a related allowance, Unpaid Contractual Balance	43,157	46,099
Total impaired loans held to maturity, Unpaid Contractual Balance	47,454	48,796
Impaired Financing Receivable, Recorded Investment [Abstract]
Impaired loans with a related allowance, Loan Balance	4,203	2,697
Impaired loans without a related allowance, Loan Balance	39,879	42,745
Total impaired loans held to maturity, Loan Balance	44,082	45,442
Impaired loans, Related Allowance Recorded	1,252	698
Impaired Financing Receivable, Average Recorded Investment [Abstract]
Impaired loans with a related allowance, Avg. Loan Balance	4,210	2,539
Impaired loans without a related allowance, Avg. Loan Balance	46,872	38,444
Total impaired loans held to maturity, Avg. Loan Balance	51,082	40,983
Impaired Financing Receivable, Interest Income, Accrual Method [Abstract]
Impaired loans with a related allowance, Interest Income Recognized	25	19
Impaired loans without a related allowance, Interest Income Recognized	384	1,395
Total impaired loans held to maturity, Interest Income Recognized	409	1,414
Commercial and commercial real estate
Impaired Financing Receivable, Unpaid Principal Balance [Abstract]
Impaired loans with a related allowance, Unpaid Contractual Balance	9,063	3,889
Impaired loans without a related allowance, Unpaid Contractual Balance	49,434	51,883
Total impaired loans held to maturity, Unpaid Contractual Balance	58,497	55,772
Impaired Financing Receivable, Recorded Investment [Abstract]
Impaired loans with a related allowance, Loan Balance	8,969	3,857
Impaired loans without a related allowance, Loan Balance	46,131	48,504
Total impaired loans held to maturity, Loan Balance	55,100	52,361
Impaired loans, Related Allowance Recorded	2,236	1,169
Impaired Financing Receivable, Average Recorded Investment [Abstract]
Impaired loans with a related allowance, Avg. Loan Balance	6,347	3,063
Impaired loans without a related allowance, Avg. Loan Balance	56,721	45,955
Total impaired loans held to maturity, Avg. Loan Balance	63,068	49,018
Impaired Financing Receivable, Interest Income, Accrual Method [Abstract]
Impaired loans with a related allowance, Interest Income Recognized	60	31
Impaired loans without a related allowance, Interest Income Recognized	527	1,910
Total impaired loans held to maturity, Interest Income Recognized	587	1,941
Agricultural and agricultural real estate
Impaired Financing Receivable, Unpaid Principal Balance [Abstract]
Impaired loans with a related allowance, Unpaid Contractual Balance	0	0
Impaired loans without a related allowance, Unpaid Contractual Balance	13,593	4,612
Total impaired loans held to maturity, Unpaid Contractual Balance	13,593	4,612
Impaired Financing Receivable, Recorded Investment [Abstract]
Impaired loans with a related allowance, Loan Balance	0	0
Impaired loans without a related allowance, Loan Balance	13,593	4,612
Total impaired loans held to maturity, Loan Balance	13,593	4,612
Impaired loans, Related Allowance Recorded	0	0
Impaired Financing Receivable, Average Recorded Investment [Abstract]
Impaired loans with a related allowance, Avg. Loan Balance	0	2,823
Impaired loans without a related allowance, Avg. Loan Balance	7,422	2,287
Total impaired loans held to maturity, Avg. Loan Balance	7,422	5,110
Impaired Financing Receivable, Interest Income, Accrual Method [Abstract]
Impaired loans with a related allowance, Interest Income Recognized	0	0
Impaired loans without a related allowance, Interest Income Recognized	251	175
Total impaired loans held to maturity, Interest Income Recognized	251	175
Residential real estate
Impaired Financing Receivable, Unpaid Principal Balance [Abstract]
Impaired loans with a related allowance, Unpaid Contractual Balance	2,868	2,210
Impaired loans without a related allowance, Unpaid Contractual Balance	16,610	15,802
Total impaired loans held to maturity, Unpaid Contractual Balance	19,478	18,012
Impaired Financing Receivable, Recorded Investment [Abstract]
Impaired loans with a related allowance, Loan Balance	2,873	2,125
Impaired loans without a related allowance, Loan Balance	16,472	15,665
Total impaired loans held to maturity, Loan Balance	19,345	17,790
Impaired loans, Related Allowance Recorded	311	393
Impaired Financing Receivable, Average Recorded Investment [Abstract]
Impaired loans with a related allowance, Avg. Loan Balance	2,917	2,524
Impaired loans without a related allowance, Avg. Loan Balance	17,173	10,186
Total impaired loans held to maturity, Avg. Loan Balance	20,090	12,710
Impaired Financing Receivable, Interest Income, Accrual Method [Abstract]
Impaired loans with a related allowance, Interest Income Recognized	4	16
Impaired loans without a related allowance, Interest Income Recognized	32	145
Total impaired loans held to maturity, Interest Income Recognized	36	161
Consumer
Impaired Financing Receivable, Unpaid Principal Balance [Abstract]
Impaired loans with a related allowance, Unpaid Contractual Balance	3,258	3,111
Impaired loans without a related allowance, Unpaid Contractual Balance	2,706	2,347
Total impaired loans held to maturity, Unpaid Contractual Balance	5,964	5,458
Impaired Financing Receivable, Recorded Investment [Abstract]
Impaired loans with a related allowance, Loan Balance	3,258	3,111
Impaired loans without a related allowance, Loan Balance	2,705	2,347
Total impaired loans held to maturity, Loan Balance	5,963	5,458
Impaired loans, Related Allowance Recorded	1,247	1,206
Impaired Financing Receivable, Average Recorded Investment [Abstract]
Impaired loans with a related allowance, Avg. Loan Balance	3,208	2,877
Impaired loans without a related allowance, Avg. Loan Balance	2,970	2,403
Total impaired loans held to maturity, Avg. Loan Balance	6,178	5,280
Impaired Financing Receivable, Interest Income, Accrual Method [Abstract]
Impaired loans with a related allowance, Interest Income Recognized	9	33
Impaired loans without a related allowance, Interest Income Recognized	9	38
Total impaired loans held to maturity, Interest Income Recognized	$ 18	$ 71