Allowance for Loan and Lease Losses (Details 2) - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015
Credit Quality Information
Recorded investment	$ 5,332,300	$ 4,995,540
Originated
Credit Quality Information
Recorded investment	4,985,923	4,572,888
Acquired
Credit Quality Information
Recorded investment	346,377	422,652
Commercial real estate
Credit Quality Information
Recorded investment	2,038,477	1,875,592
Commercial real estate | Originated
Credit Quality Information
Recorded investment	1,880,163	1,684,548
Commercial real estate | Acquired
Credit Quality Information
Recorded investment	158,314	191,044
Commercial real estate | Pass | Originated
Credit Quality Information
Recorded investment	1,874,534	1,668,891
Commercial real estate | Pass | Acquired
Credit Quality Information
Recorded investment	147,218	182,377
Commercial real estate | OAEM | Originated
Credit Quality Information
Recorded investment	1,546	12,781
Commercial real estate | OAEM | Acquired
Credit Quality Information
Recorded investment	1,424	1,202
Commercial real estate | Substandard | Originated
Credit Quality Information
Recorded investment	3,457	780
Commercial real estate | Substandard | Acquired
Credit Quality Information
Recorded investment	9,570	7,066
Commercial real estate | Doubtful | Originated
Credit Quality Information
Recorded investment	626	2,096
Commercial real estate | Doubtful | Acquired
Credit Quality Information
Recorded investment	102	399
Multi-family mortgage
Credit Quality Information
Recorded investment	703,743	658,480
Multi-family mortgage | Originated
Credit Quality Information
Recorded investment	673,108	620,865
Multi-family mortgage | Acquired
Credit Quality Information
Recorded investment	30,635	37,615
Multi-family mortgage | Pass | Originated
Credit Quality Information
Recorded investment	671,690	619,786
Multi-family mortgage | Pass | Acquired
Credit Quality Information
Recorded investment	29,913	35,785
Multi-family mortgage | OAEM | Originated
Credit Quality Information
Recorded investment	0	788
Multi-family mortgage | OAEM | Acquired
Credit Quality Information
Recorded investment	404	612
Multi-family mortgage | Substandard | Originated
Credit Quality Information
Recorded investment	1,418	291
Multi-family mortgage | Substandard | Acquired
Credit Quality Information
Recorded investment	318	1,218
Multi-family mortgage | Doubtful | Originated
Credit Quality Information
Recorded investment	0	0
Multi-family mortgage | Doubtful | Acquired
Credit Quality Information
Recorded investment	0	0
Construction
Credit Quality Information
Recorded investment	141,208	130,322
Construction | Originated
Credit Quality Information
Recorded investment	140,990	129,742
Construction | Acquired
Credit Quality Information
Recorded investment	218	580
Construction | Pass | Originated
Credit Quality Information
Recorded investment	140,802	129,534
Construction | Pass | Acquired
Credit Quality Information
Recorded investment	218	580
Construction | OAEM | Originated
Credit Quality Information
Recorded investment	188	208
Construction | OAEM | Acquired
Credit Quality Information
Recorded investment	0	0
Construction | Substandard | Originated
Credit Quality Information
Recorded investment	0	0
Construction | Substandard | Acquired
Credit Quality Information
Recorded investment	0	0
Construction | Doubtful | Originated
Credit Quality Information
Recorded investment	0	0
Construction | Doubtful | Acquired
Credit Quality Information
Recorded investment	0	0
Commercial
Credit Quality Information
Recorded investment	652,316	592,531
Commercial | Originated
Credit Quality Information
Recorded investment	636,658	576,599
Commercial | Acquired
Credit Quality Information
Recorded investment	15,658	15,932
Commercial | Pass | Originated
Credit Quality Information
Recorded investment	604,282	562,615
Commercial | Pass | Acquired
Credit Quality Information
Recorded investment	11,203	11,959
Commercial | OAEM | Originated
Credit Quality Information
Recorded investment	7,540	9,976
Commercial | OAEM | Acquired
Credit Quality Information
Recorded investment	464	902
Commercial | Substandard | Originated
Credit Quality Information
Recorded investment	24,692	1,714
Commercial | Substandard | Acquired
Credit Quality Information
Recorded investment	3,018	3,071
Commercial | Doubtful | Originated
Credit Quality Information
Recorded investment	144	2,294
Commercial | Doubtful | Acquired
Credit Quality Information
Recorded investment	973	0
Equipment Financing
Credit Quality Information
Recorded investment	764,647	721,890
Equipment Financing | Originated
Credit Quality Information
Recorded investment	758,086	712,988
Equipment Financing | Acquired
Credit Quality Information
Recorded investment	6,561	8,902
Equipment Financing | Pass | Originated
Credit Quality Information
Recorded investment	750,322	709,381
Equipment Financing | Pass | Acquired
Credit Quality Information
Recorded investment	6,553	8,902
Equipment Financing | OAEM | Originated
Credit Quality Information
Recorded investment	1,039	804
Equipment Financing | OAEM | Acquired
Credit Quality Information
Recorded investment	0	0
Equipment Financing | Substandard | Originated
Credit Quality Information
Recorded investment	5,989	1,414
Equipment Financing | Substandard | Acquired
Credit Quality Information
Recorded investment	0	0
Equipment Financing | Doubtful | Originated
Credit Quality Information
Recorded investment	736	1,389
Equipment Financing | Doubtful | Acquired
Credit Quality Information
Recorded investment	8	0
Condominium association
Credit Quality Information
Recorded investment	53,903	59,875
Condominium association | Originated
Credit Quality Information
Recorded investment	53,903	59,875
Condominium association | Acquired
Credit Quality Information
Recorded investment	0	0
Condominium association | Pass | Originated
Credit Quality Information
Recorded investment	53,903	59,875
Condominium association | Pass | Acquired
Credit Quality Information
Recorded investment	0	0
Condominium association | OAEM | Originated
Credit Quality Information
Recorded investment	0	0
Condominium association | OAEM | Acquired
Credit Quality Information
Recorded investment	0	0
Condominium association | Substandard | Originated
Credit Quality Information
Recorded investment	0	0
Condominium association | Substandard | Acquired
Credit Quality Information
Recorded investment	0	0
Condominium association | Doubtful | Originated
Credit Quality Information
Recorded investment	0	0
Condominium association | Doubtful | Acquired
Credit Quality Information
Recorded investment	0	0
Other Consumer
Credit Quality Information
Recorded investment	12,380	12,170
Other Consumer | Originated
Credit Quality Information
Recorded investment	12,254	12,039
Other Consumer | Acquired
Credit Quality Information
Recorded investment	126	131
Other Consumer | Pass | Originated
Credit Quality Information
Recorded investment	12,219	12,017
Other Consumer | Pass | Acquired
Credit Quality Information
Recorded investment	126	131
Other Consumer | OAEM | Originated
Credit Quality Information
Recorded investment	0	0
Other Consumer | OAEM | Acquired
Credit Quality Information
Recorded investment	0	0
Other Consumer | Substandard | Originated
Credit Quality Information
Recorded investment	35	22
Other Consumer | Substandard | Acquired
Credit Quality Information
Recorded investment	0	0
Other Consumer | Doubtful | Originated
Credit Quality Information
Recorded investment	0	0
Other Consumer | Doubtful | Acquired
Credit Quality Information
Recorded investment	0	0
Indirect Automobile
Credit Quality Information
Recorded investment	7,607	13,678
Indirect Automobile | Originated
Credit Quality Information
Recorded investment	$ 7,607	$ 13,678
Percentage of loans to aggregate outstanding amount	100.00%	100.00%
Indirect Automobile | Acquired
Credit Quality Information
Recorded investment	$ 0	$ 0
Indirect Automobile | Credit score, Over 700 | Originated
Credit Quality Information
Recorded investment	$ 3,044	$ 5,435
Percentage of loans to aggregate outstanding amount	40.00%	39.70%
Indirect Automobile | Credit score, 661-700 | Originated
Credit Quality Information
Recorded investment	$ 1,145	$ 1,965
Percentage of loans to aggregate outstanding amount	15.00%	14.40%
Indirect Automobile | Credit score, 660 and below | Originated
Credit Quality Information
Recorded investment	$ 3,391	$ 6,217
Percentage of loans to aggregate outstanding amount	44.60%	45.50%
Indirect Automobile | Data not available | Originated
Credit Quality Information
Recorded investment	$ 27	$ 61
Percentage of loans to aggregate outstanding amount	0.40%	0.40%
Residential mortgage
Credit Quality Information
Recorded investment	$ 617,065	$ 616,449
Percentage of loans to aggregate outstanding amount	100.00%	100.00%
Residential mortgage | Originated
Credit Quality Information
Recorded investment	$ 540,650	$ 527,846
Percentage of loans to aggregate outstanding amount	87.60%	85.60%
Residential mortgage | Acquired
Credit Quality Information
Recorded investment	$ 76,415	$ 88,603
Percentage of loans to aggregate outstanding amount	12.40%	14.40%
Residential mortgage | Loan-to-value ratio, less than 50% | Originated
Credit Quality Information
Recorded investment	$ 126,290	$ 118,628
Percentage of loans to aggregate outstanding amount	20.50%	19.20%
Residential mortgage | Loan-to-value ratio, less than 50% | Acquired
Credit Quality Information
Recorded investment	$ 17,034	$ 18,857
Percentage of loans to aggregate outstanding amount	2.70%	3.10%
Residential mortgage | Loan-to-value ratio, 50% - 69% | Originated
Credit Quality Information
Recorded investment	$ 224,791	$ 214,390
Percentage of loans to aggregate outstanding amount	36.40%	34.80%
Residential mortgage | Loan-to-value ratio, 50% - 69% | Acquired
Credit Quality Information
Recorded investment	$ 28,240	$ 32,986
Percentage of loans to aggregate outstanding amount	4.60%	5.30%
Residential mortgage | Loan-to-value ratio, 70% - 79% | Originated
Credit Quality Information
Recorded investment	$ 166,363	$ 173,774
Percentage of loans to aggregate outstanding amount	26.90%	28.20%
Residential mortgage | Loan-to-value ratio, 70% - 79% | Acquired
Credit Quality Information
Recorded investment	$ 15,165	$ 17,883
Percentage of loans to aggregate outstanding amount	2.50%	2.90%
Residential mortgage | Loan-to-value ratio, 80% and over | Originated
Credit Quality Information
Recorded investment	$ 18,336	$ 17,808
Percentage of loans to aggregate outstanding amount	3.00%	2.90%
Residential mortgage | Loan-to-value ratio, 80% and over | Acquired
Credit Quality Information
Recorded investment	$ 11,416	$ 14,011
Percentage of loans to aggregate outstanding amount	1.90%	2.30%
Residential mortgage | Data not available | Originated
Credit Quality Information
Recorded investment	$ 4,870	$ 3,246
Percentage of loans to aggregate outstanding amount	0.80%	0.50%
Residential mortgage | Data not available | Acquired
Credit Quality Information
Recorded investment	$ 4,560	$ 4,866
Percentage of loans to aggregate outstanding amount	0.70%	0.80%
Home Equity
Credit Quality Information
Recorded investment	$ 340,954	$ 314,553
Percentage of loans to aggregate outstanding amount	100.00%	100.00%
Home Equity | Originated
Credit Quality Information
Recorded investment	$ 282,504	$ 234,708
Percentage of loans to aggregate outstanding amount	82.90%	74.60%
Home Equity | Acquired
Credit Quality Information
Recorded investment	$ 58,450	$ 79,845
Percentage of loans to aggregate outstanding amount	17.10%	25.40%
Home Equity | Loan-to-value ratio, less than 50% | Originated
Credit Quality Information
Recorded investment	$ 153,001	$ 131,584
Percentage of loans to aggregate outstanding amount	44.90%	41.80%
Home Equity | Loan-to-value ratio, less than 50% | Acquired
Credit Quality Information
Recorded investment	$ 36,541	$ 48,563
Percentage of loans to aggregate outstanding amount	10.70%	15.40%
Home Equity | Loan-to-value ratio, 50% - 69% | Originated
Credit Quality Information
Recorded investment	$ 59,629	$ 51,492
Percentage of loans to aggregate outstanding amount	17.60%	16.40%
Home Equity | Loan-to-value ratio, 50% - 69% | Acquired
Credit Quality Information
Recorded investment	$ 15,939	$ 20,623
Percentage of loans to aggregate outstanding amount	4.70%	6.60%
Home Equity | Loan-to-value ratio, 70% - 79% | Originated
Credit Quality Information
Recorded investment	$ 45,455	$ 32,916
Percentage of loans to aggregate outstanding amount	13.30%	10.50%
Home Equity | Loan-to-value ratio, 70% - 79% | Acquired
Credit Quality Information
Recorded investment	$ 3,459	$ 7,144
Percentage of loans to aggregate outstanding amount	1.00%	2.30%
Home Equity | Loan-to-value ratio, 80% and over | Originated
Credit Quality Information
Recorded investment	$ 23,678	$ 18,082
Percentage of loans to aggregate outstanding amount	6.90%	5.70%
Home Equity | Loan-to-value ratio, 80% and over | Acquired
Credit Quality Information
Recorded investment	$ 1,116	$ 2,650
Percentage of loans to aggregate outstanding amount	0.30%	0.80%
Home Equity | Data not available | Originated
Credit Quality Information
Recorded investment	$ 741	$ 634
Percentage of loans to aggregate outstanding amount	0.20%	0.20%
Home Equity | Data not available | Acquired
Credit Quality Information
Recorded investment	$ 1,395	$ 865
Percentage of loans to aggregate outstanding amount	0.40%	0.30%