Allowance for Loan Losses and Credit Quality of Loans, Credit Quality by Loan Class (Details) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2014	Dec. 31, 2013
Commercial Credit Exposure [Member] | ACQUIRED [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	$ 312,903	$ 332,240
Commercial Credit Exposure [Member] | Pass [Member] | ACQUIRED [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	282,341	290,702
Commercial Credit Exposure [Member] | Special Mention [Member] | ACQUIRED [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	6,817	8,413
Commercial Credit Exposure [Member] | Substandard [Member] | ACQUIRED [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	23,745	33,125
Commercial Credit Exposure [Member] | Commercial Loans [Member] | ORIGINATED [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	1,758,042	1,652,553
Commercial Credit Exposure [Member] | Commercial Loans [Member] | Pass [Member] | ORIGINATED [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	1,644,377	1,547,669
Commercial Credit Exposure [Member] | Commercial Loans [Member] | Special Mention [Member] | ORIGINATED [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	32,092	40,037
Commercial Credit Exposure [Member] | Commercial Loans [Member] | Substandard [Member] | ORIGINATED [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	81,497	64,835
Commercial Credit Exposure [Member] | Commercial Loans [Member] | Doubtful [Member] | ORIGINATED [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	76	12
Commercial Credit Exposure [Member] | Commercial [Member] | ACQUIRED [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	98,688	103,226
Commercial Credit Exposure [Member] | Commercial [Member] | ORIGINATED [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	657,206	616,423
Commercial Credit Exposure [Member] | Commercial [Member] | Pass [Member] | ACQUIRED [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	84,842	85,692
Commercial Credit Exposure [Member] | Commercial [Member] | Pass [Member] | ORIGINATED [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	606,388	576,079
Commercial Credit Exposure [Member] | Commercial [Member] | Special Mention [Member] | ACQUIRED [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	4,339	2,230
Commercial Credit Exposure [Member] | Commercial [Member] | Special Mention [Member] | ORIGINATED [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	11,782	16,836
Commercial Credit Exposure [Member] | Commercial [Member] | Substandard [Member] | ACQUIRED [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	9,507	15,304
Commercial Credit Exposure [Member] | Commercial [Member] | Substandard [Member] | ORIGINATED [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	39,036	23,508
Commercial Credit Exposure [Member] | Commercial [Member] | Doubtful [Member] | ORIGINATED [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	0	0
Commercial Credit Exposure [Member] | Commercial Real Estate [Member] | ACQUIRED [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	214,215	229,014
Commercial Credit Exposure [Member] | Commercial Real Estate [Member] | ORIGINATED [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	1,001,389	934,316
Commercial Credit Exposure [Member] | Commercial Real Estate [Member] | Pass [Member] | ACQUIRED [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	197,499	205,010
Commercial Credit Exposure [Member] | Commercial Real Estate [Member] | Pass [Member] | ORIGINATED [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	946,883	878,411
Commercial Credit Exposure [Member] | Commercial Real Estate [Member] | Special Mention [Member] | ACQUIRED [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	2,478	6,183
Commercial Credit Exposure [Member] | Commercial Real Estate [Member] | Special Mention [Member] | ORIGINATED [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	19,949	22,777
Commercial Credit Exposure [Member] | Commercial Real Estate [Member] | Substandard [Member] | ACQUIRED [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	14,238	17,821
Commercial Credit Exposure [Member] | Commercial Real Estate [Member] | Substandard [Member] | ORIGINATED [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	34,557	33,128
Commercial Credit Exposure [Member] | Commercial Real Estate [Member] | Doubtful [Member] | ORIGINATED [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	0	0
Commercial Credit Exposure [Member] | Agricultural [Member] | ACQUIRED [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	0	0
Commercial Credit Exposure [Member] | Agricultural [Member] | ORIGINATED [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	57,085	65,162
Commercial Credit Exposure [Member] | Agricultural [Member] | Pass [Member] | ACQUIRED [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	0	0
Commercial Credit Exposure [Member] | Agricultural [Member] | Pass [Member] | ORIGINATED [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	52,603	60,043
Commercial Credit Exposure [Member] | Agricultural [Member] | Special Mention [Member] | ACQUIRED [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	0	0
Commercial Credit Exposure [Member] | Agricultural [Member] | Special Mention [Member] | ORIGINATED [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	354	381
Commercial Credit Exposure [Member] | Agricultural [Member] | Substandard [Member] | ACQUIRED [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	0	0
Commercial Credit Exposure [Member] | Agricultural [Member] | Substandard [Member] | ORIGINATED [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	4,052	4,726
Commercial Credit Exposure [Member] | Agricultural [Member] | Doubtful [Member] | ORIGINATED [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	76	12
Commercial Credit Exposure [Member] | Agricultural Real Estate [Member] | ORIGINATED [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	42,362	36,652
Commercial Credit Exposure [Member] | Agricultural Real Estate [Member] | Pass [Member] | ORIGINATED [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	38,503	33,136
Commercial Credit Exposure [Member] | Agricultural Real Estate [Member] | Special Mention [Member] | ORIGINATED [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	7	43
Commercial Credit Exposure [Member] | Agricultural Real Estate [Member] | Substandard [Member] | ORIGINATED [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	3,852	3,473
Commercial Credit Exposure [Member] | Agricultural Real Estate [Member] | Doubtful [Member] | ORIGINATED [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	0	0
Consumer Credit Exposure [Member] | Consumer Loans [Member] | ACQUIRED [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	179,253	219,587
Consumer Credit Exposure [Member] | Consumer Loans [Member] | ORIGINATED [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	1,845,782	1,752,950
Consumer Credit Exposure [Member] | Consumer Loans [Member] | Nonperforming [Member] | ACQUIRED [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	764	792
Consumer Credit Exposure [Member] | Consumer Loans [Member] | Nonperforming [Member] | ORIGINATED [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	11,164	10,222
Consumer Credit Exposure [Member] | Consumer Loans [Member] | Performing [Member] | ACQUIRED [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	178,489	218,795
Consumer Credit Exposure [Member] | Consumer Loans [Member] | Performing [Member] | ORIGINATED [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	1,834,618	1,742,728
Consumer Credit Exposure [Member] | Indirect [Member] | ACQUIRED [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	91,979	125,086
Consumer Credit Exposure [Member] | Indirect [Member] | ORIGINATED [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	1,282,058	1,161,844
Consumer Credit Exposure [Member] | Indirect [Member] | Nonperforming [Member] | ACQUIRED [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	172	164
Consumer Credit Exposure [Member] | Indirect [Member] | Nonperforming [Member] | ORIGINATED [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	2,459	3,044
Consumer Credit Exposure [Member] | Indirect [Member] | Performing [Member] | ACQUIRED [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	91,807	124,922
Consumer Credit Exposure [Member] | Indirect [Member] | Performing [Member] | ORIGINATED [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	1,279,599	1,158,800
Consumer Credit Exposure [Member] | Home Equity Member] | ACQUIRED [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	81,192	87,076
Consumer Credit Exposure [Member] | Home Equity Member] | ORIGINATED [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	508,199	532,823
Consumer Credit Exposure [Member] | Home Equity Member] | Nonperforming [Member] | ACQUIRED [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	550	570
Consumer Credit Exposure [Member] | Home Equity Member] | Nonperforming [Member] | ORIGINATED [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	8,611	7,046
Consumer Credit Exposure [Member] | Home Equity Member] | Performing [Member] | ACQUIRED [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	80,642	86,506
Consumer Credit Exposure [Member] | Home Equity Member] | Performing [Member] | ORIGINATED [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	499,588	525,777
Consumer Credit Exposure [Member] | Direct [Member] | ACQUIRED [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	6,082	7,425
Consumer Credit Exposure [Member] | Direct [Member] | ORIGINATED [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	55,525	58,283
Consumer Credit Exposure [Member] | Direct [Member] | Nonperforming [Member] | ACQUIRED [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	42	58
Consumer Credit Exposure [Member] | Direct [Member] | Nonperforming [Member] | ORIGINATED [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	94	132
Consumer Credit Exposure [Member] | Direct [Member] | Performing [Member] | ACQUIRED [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	6,040	7,367
Consumer Credit Exposure [Member] | Direct [Member] | Performing [Member] | ORIGINATED [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	55,431	58,151
Residential Mortgage Credit Exposure [Member] | ACQUIRED [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	289,405	308,416
Residential Mortgage Credit Exposure [Member] | ORIGINATED [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	783,802	733,221
Residential Mortgage Credit Exposure [Member] | Nonperforming [Member] | ACQUIRED [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	3,498	3,872
Residential Mortgage Credit Exposure [Member] | Nonperforming [Member] | ORIGINATED [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	7,830	7,913
Residential Mortgage Credit Exposure [Member] | Performing [Member] | ACQUIRED [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	285,907	304,544
Residential Mortgage Credit Exposure [Member] | Performing [Member] | ORIGINATED [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	775,972	725,308
Residential Mortgage Credit Exposure [Member] | Residential Mortgage [Member] | ACQUIRED [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	289,405	308,416
Residential Mortgage Credit Exposure [Member] | Residential Mortgage [Member] | ORIGINATED [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	783,802	733,221
Residential Mortgage Credit Exposure [Member] | Residential Mortgage [Member] | Nonperforming [Member] | ACQUIRED [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	3,498	3,872
Residential Mortgage Credit Exposure [Member] | Residential Mortgage [Member] | Nonperforming [Member] | ORIGINATED [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	7,830	7,913
Residential Mortgage Credit Exposure [Member] | Residential Mortgage [Member] | Performing [Member] | ACQUIRED [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	285,907	304,544
Residential Mortgage Credit Exposure [Member] | Residential Mortgage [Member] | Performing [Member] | ORIGINATED [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	775,972	725,308
Business Banking Credit Exposure [Member] | Commercial Loans [Member] | ACQUIRED [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	64,587	70,149
Business Banking Credit Exposure [Member] | Commercial Loans [Member] | ORIGINATED [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	340,714	337,679
Business Banking Credit Exposure [Member] | Commercial Loans [Member] | Non-classified [Member] | ACQUIRED [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	59,227	65,437
Business Banking Credit Exposure [Member] | Commercial Loans [Member] | Non-classified [Member] | ORIGINATED [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	323,200	319,578
Business Banking Credit Exposure [Member] | Commercial Loans [Member] | Classified [Member] | ACQUIRED [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	5,360	4,712
Business Banking Credit Exposure [Member] | Commercial Loans [Member] | Classified [Member] | ORIGINATED [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	17,514	18,101
Business Banking Credit Exposure [Member] | Business Banking [Member] | ACQUIRED [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	64,587	70,149
Business Banking Credit Exposure [Member] | Business Banking [Member] | ORIGINATED [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	340,714	337,679
Business Banking Credit Exposure [Member] | Business Banking [Member] | Non-classified [Member] | ACQUIRED [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	59,227	65,437
Business Banking Credit Exposure [Member] | Business Banking [Member] | Non-classified [Member] | ORIGINATED [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	323,200	319,578
Business Banking Credit Exposure [Member] | Business Banking [Member] | Classified [Member] | ACQUIRED [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	5,360	4,712
Business Banking Credit Exposure [Member] | Business Banking [Member] | Classified [Member] | ORIGINATED [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	$ 17,514	$ 18,101