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Allowance for Credit Losses and Credit Quality of Loans, Past Due Loans (Details) $ in Thousands	Jun. 30, 2020 USD ($) Relationship	Mar. 31, 2020 USD ($) Relationship	Dec. 31, 2019 USD ($)
Allowance for Credit Losses and Credit Quality of Loans [Abstract]
Individually evaluated loans, number of relationships | Relationship	0	1
Individually evaluated loans, amortized cost		$ 4,200
Individually evaluated loans, allowance for credit losses		$ 2,100
Financing Receivable, Recorded Investment, Aging [Abstract]
Total past due accruing	$ 22,426		$ 34,803
Nonaccrual	25,567		25,174
Current	7,579,998		7,076,121
Recorded total loans	7,627,991		7,136,098
Loans in non-accrual without an allowance for credit losses	0
31-60 Days Past Due Accruing [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total past due accruing	14,931		25,610
61-90 Days Past Due Accruing [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total past due accruing	5,438		5,476
Greater Than 90 Days Past Due Accruing [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total past due accruing	2,057		3,717
Commercial Loans [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total past due accruing	2,247
Nonaccrual	11,542
Current	3,961,153
Recorded total loans	3,974,942
Commercial Loans [Member] | 31-60 Days Past Due Accruing [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total past due accruing	921
Commercial Loans [Member] | 61-90 Days Past Due Accruing [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total past due accruing	1,236
Commercial Loans [Member] | Greater Than 90 Days Past Due Accruing [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total past due accruing	90
Commercial Loans [Member] | Commercial & Industrial [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total past due accruing	679
Nonaccrual	2,992
Current	1,125,180
Recorded total loans	1,128,851
Commercial Loans [Member] | Commercial & Industrial [Member] | 31-60 Days Past Due Accruing [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total past due accruing	550
Commercial Loans [Member] | Commercial & Industrial [Member] | 61-90 Days Past Due Accruing [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total past due accruing	39
Commercial Loans [Member] | Commercial & Industrial [Member] | Greater Than 90 Days Past Due Accruing [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total past due accruing	90
Commercial Loans [Member] | Commercial Real Estate [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total past due accruing	1,568
Nonaccrual	8,550
Current	2,325,876
Recorded total loans	2,335,994
Commercial Loans [Member] | Commercial Real Estate [Member] | 31-60 Days Past Due Accruing [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total past due accruing	371
Commercial Loans [Member] | Commercial Real Estate [Member] | 61-90 Days Past Due Accruing [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total past due accruing	1,197
Commercial Loans [Member] | Commercial Real Estate [Member] | Greater Than 90 Days Past Due Accruing [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total past due accruing	0
Commercial Loans [Member] | Paycheck Protection Plan [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total past due accruing	0
Nonaccrual	0
Current	510,097
Recorded total loans	510,097
Commercial Loans [Member] | Paycheck Protection Plan [Member] | 31-60 Days Past Due Accruing [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total past due accruing	0
Commercial Loans [Member] | Paycheck Protection Plan [Member] | 61-90 Days Past Due Accruing [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total past due accruing	0
Commercial Loans [Member] | Paycheck Protection Plan [Member] | Greater Than 90 Days Past Due Accruing [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total past due accruing	0
Consumer Loans [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total past due accruing	14,001
Nonaccrual	2,695
Current	1,624,340
Recorded total loans	1,641,036
Consumer Loans [Member] | 31-60 Days Past Due Accruing [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total past due accruing	9,322
Consumer Loans [Member] | 61-90 Days Past Due Accruing [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total past due accruing	2,964
Consumer Loans [Member] | Greater Than 90 Days Past Due Accruing [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total past due accruing	1,715
Consumer Loans [Member] | Auto [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total past due accruing	8,103
Nonaccrual	2,452
Current	1,038,232
Recorded total loans	1,048,787
Consumer Loans [Member] | Auto [Member] | 31-60 Days Past Due Accruing [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total past due accruing	6,012
Consumer Loans [Member] | Auto [Member] | 61-90 Days Past Due Accruing [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total past due accruing	1,418
Consumer Loans [Member] | Auto [Member] | Greater Than 90 Days Past Due Accruing [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total past due accruing	673
Consumer Loans [Member] | Other Consumer [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total past due accruing	5,898
Nonaccrual	243
Current	586,108
Recorded total loans	592,249
Consumer Loans [Member] | Other Consumer [Member] | 31-60 Days Past Due Accruing [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total past due accruing	3,310
Consumer Loans [Member] | Other Consumer [Member] | 61-90 Days Past Due Accruing [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total past due accruing	1,546
Consumer Loans [Member] | Other Consumer [Member] | Greater Than 90 Days Past Due Accruing [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total past due accruing	1,042
Residential [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total past due accruing	6,178
Nonaccrual	11,330
Current	1,994,505
Recorded total loans	2,012,013
Residential [Member] | 31-60 Days Past Due Accruing [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total past due accruing	4,688
Residential [Member] | 61-90 Days Past Due Accruing [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total past due accruing	1,238
Residential [Member] | Greater Than 90 Days Past Due Accruing [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total past due accruing	$ 252
Originated Loans [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total past due accruing			32,917
Nonaccrual			23,581
Current			6,814,722
Recorded total loans			6,871,220
Originated Loans [Member] | 31-60 Days Past Due Accruing [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total past due accruing			24,353
Originated Loans [Member] | 61-90 Days Past Due Accruing [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total past due accruing			5,111
Originated Loans [Member] | Greater Than 90 Days Past Due Accruing [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total past due accruing			3,453
Originated Loans [Member] | Commercial Loans [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total past due accruing			5,759
Nonaccrual			13,059
Current			3,310,182
Recorded total loans			3,329,000
Originated Loans [Member] | Commercial Loans [Member] | 31-60 Days Past Due Accruing [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total past due accruing			5,597
Originated Loans [Member] | Commercial Loans [Member] | 61-90 Days Past Due Accruing [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total past due accruing			162
Originated Loans [Member] | Commercial Loans [Member] | Greater Than 90 Days Past Due Accruing [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total past due accruing			0
Originated Loans [Member] | Commercial Loans [Member] | Commercial & Industrial [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total past due accruing			1,227
Nonaccrual			1,177
Current			838,502
Recorded total loans			840,906
Originated Loans [Member] | Commercial Loans [Member] | Commercial & Industrial [Member] | 31-60 Days Past Due Accruing [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total past due accruing			1,227
Originated Loans [Member] | Commercial Loans [Member] | Commercial & Industrial [Member] | 61-90 Days Past Due Accruing [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total past due accruing			0
Originated Loans [Member] | Commercial Loans [Member] | Commercial & Industrial [Member] | Greater Than 90 Days Past Due Accruing [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total past due accruing			0
Originated Loans [Member] | Commercial Loans [Member] | Commercial Real Estate [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total past due accruing			3,576
Nonaccrual			4,847
Current			1,941,143
Recorded total loans			1,949,566
Originated Loans [Member] | Commercial Loans [Member] | Commercial Real Estate [Member] | 31-60 Days Past Due Accruing [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total past due accruing			3,576
Originated Loans [Member] | Commercial Loans [Member] | Commercial Real Estate [Member] | 61-90 Days Past Due Accruing [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total past due accruing			0
Originated Loans [Member] | Commercial Loans [Member] | Commercial Real Estate [Member] | Greater Than 90 Days Past Due Accruing [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total past due accruing			0
Originated Loans [Member] | Commercial Loans [Member] | Business Banking [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total past due accruing			956
Nonaccrual			7,035
Current			530,537
Recorded total loans			538,528
Originated Loans [Member] | Commercial Loans [Member] | Business Banking [Member] | 31-60 Days Past Due Accruing [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total past due accruing			794
Originated Loans [Member] | Commercial Loans [Member] | Business Banking [Member] | 61-90 Days Past Due Accruing [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total past due accruing			162
Originated Loans [Member] | Commercial Loans [Member] | Business Banking [Member] | Greater Than 90 Days Past Due Accruing [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total past due accruing			0
Originated Loans [Member] | Consumer Loans [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total past due accruing			25,126
Nonaccrual			4,650
Current			2,193,167
Recorded total loans			2,222,943
Originated Loans [Member] | Consumer Loans [Member] | 31-60 Days Past Due Accruing [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total past due accruing			17,577
Originated Loans [Member] | Consumer Loans [Member] | 61-90 Days Past Due Accruing [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total past due accruing			4,759
Originated Loans [Member] | Consumer Loans [Member] | Greater Than 90 Days Past Due Accruing [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total past due accruing			2,790
Originated Loans [Member] | Consumer Loans [Member] | Indirect Auto [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total past due accruing			14,973
Nonaccrual			2,175
Current			1,176,487
Recorded total loans			1,193,635
Originated Loans [Member] | Consumer Loans [Member] | Indirect Auto [Member] | 31-60 Days Past Due Accruing [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total past due accruing			11,860
Originated Loans [Member] | Consumer Loans [Member] | Indirect Auto [Member] | 61-90 Days Past Due Accruing [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total past due accruing			2,108
Originated Loans [Member] | Consumer Loans [Member] | Indirect Auto [Member] | Greater Than 90 Days Past Due Accruing [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total past due accruing			1,005
Originated Loans [Member] | Consumer Loans [Member] | Specialty Lending [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total past due accruing			6,547
Nonaccrual			0
Current			535,516
Recorded total loans			542,063
Originated Loans [Member] | Consumer Loans [Member] | Specialty Lending [Member] | 31-60 Days Past Due Accruing [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total past due accruing			3,153
Originated Loans [Member] | Consumer Loans [Member] | Specialty Lending [Member] | 61-90 Days Past Due Accruing [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total past due accruing			2,087
Originated Loans [Member] | Consumer Loans [Member] | Specialty Lending [Member] | Greater Than 90 Days Past Due Accruing [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total past due accruing			1,307
Originated Loans [Member] | Consumer Loans [Member] | Direct [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total past due accruing			3,606
Nonaccrual			2,475
Current			481,164
Recorded total loans			487,245
Originated Loans [Member] | Consumer Loans [Member] | Direct [Member] | 31-60 Days Past Due Accruing [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total past due accruing			2,564
Originated Loans [Member] | Consumer Loans [Member] | Direct [Member] | 61-90 Days Past Due Accruing [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total past due accruing			564
Originated Loans [Member] | Consumer Loans [Member] | Direct [Member] | Greater Than 90 Days Past Due Accruing [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total past due accruing			478
Originated Loans [Member] | Residential [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total past due accruing			2,032
Nonaccrual			5,872
Current			1,311,373
Recorded total loans			1,319,277
Originated Loans [Member] | Residential [Member] | 31-60 Days Past Due Accruing [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total past due accruing			1,179
Originated Loans [Member] | Residential [Member] | 61-90 Days Past Due Accruing [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total past due accruing			190
Originated Loans [Member] | Residential [Member] | Greater Than 90 Days Past Due Accruing [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total past due accruing			663
Acquired Loans [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total past due accruing			1,886
Nonaccrual			1,593
Current			261,399
Recorded total loans			264,878
Acquired Loans [Member] | 31-60 Days Past Due Accruing [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total past due accruing			1,257
Acquired Loans [Member] | 61-90 Days Past Due Accruing [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total past due accruing			365
Acquired Loans [Member] | Greater Than 90 Days Past Due Accruing [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total past due accruing			264
Acquired Loans [Member] | Commercial Loans [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total past due accruing			833
Nonaccrual			382
Current			114,051
Recorded total loans			115,266
Acquired Loans [Member] | Commercial Loans [Member] | 31-60 Days Past Due Accruing [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total past due accruing			546
Acquired Loans [Member] | Commercial Loans [Member] | 61-90 Days Past Due Accruing [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total past due accruing			287
Acquired Loans [Member] | Commercial Loans [Member] | Greater Than 90 Days Past Due Accruing [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total past due accruing			0
Acquired Loans [Member] | Commercial Loans [Member] | Commercial & Industrial [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total past due accruing			149
Nonaccrual			0
Current			19,215
Recorded total loans			19,364
Acquired Loans [Member] | Commercial Loans [Member] | Commercial & Industrial [Member] | 31-60 Days Past Due Accruing [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total past due accruing			149
Acquired Loans [Member] | Commercial Loans [Member] | Commercial & Industrial [Member] | 61-90 Days Past Due Accruing [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total past due accruing			0
Acquired Loans [Member] | Commercial Loans [Member] | Commercial & Industrial [Member] | Greater Than 90 Days Past Due Accruing [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total past due accruing			0
Acquired Loans [Member] | Commercial Loans [Member] | Commercial Real Estate [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total past due accruing			0
Nonaccrual			0
Current			60,937
Recorded total loans			60,937
Acquired Loans [Member] | Commercial Loans [Member] | Commercial Real Estate [Member] | 31-60 Days Past Due Accruing [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total past due accruing			0
Acquired Loans [Member] | Commercial Loans [Member] | Commercial Real Estate [Member] | 61-90 Days Past Due Accruing [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total past due accruing			0
Acquired Loans [Member] | Commercial Loans [Member] | Commercial Real Estate [Member] | Greater Than 90 Days Past Due Accruing [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total past due accruing			0
Acquired Loans [Member] | Commercial Loans [Member] | Business Banking [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total past due accruing			684
Nonaccrual			382
Current			33,899
Recorded total loans			34,965
Acquired Loans [Member] | Commercial Loans [Member] | Business Banking [Member] | 31-60 Days Past Due Accruing [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total past due accruing			397
Acquired Loans [Member] | Commercial Loans [Member] | Business Banking [Member] | 61-90 Days Past Due Accruing [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total past due accruing			287
Acquired Loans [Member] | Commercial Loans [Member] | Business Banking [Member] | Greater Than 90 Days Past Due Accruing [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total past due accruing			0
Acquired Loans [Member] | Consumer Loans [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total past due accruing			194
Nonaccrual			105
Current			23,434
Recorded total loans			23,733
Acquired Loans [Member] | Consumer Loans [Member] | 31-60 Days Past Due Accruing [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total past due accruing			136
Acquired Loans [Member] | Consumer Loans [Member] | 61-90 Days Past Due Accruing [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total past due accruing			58
Acquired Loans [Member] | Consumer Loans [Member] | Greater Than 90 Days Past Due Accruing [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total past due accruing			0
Acquired Loans [Member] | Consumer Loans [Member] | Direct [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total past due accruing			194
Nonaccrual			105
Current			23,434
Recorded total loans			23,733
Acquired Loans [Member] | Consumer Loans [Member] | Direct [Member] | 31-60 Days Past Due Accruing [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total past due accruing			136
Acquired Loans [Member] | Consumer Loans [Member] | Direct [Member] | 61-90 Days Past Due Accruing [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total past due accruing			58
Acquired Loans [Member] | Consumer Loans [Member] | Direct [Member] | Greater Than 90 Days Past Due Accruing [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total past due accruing			0
Acquired Loans [Member] | Residential [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total past due accruing			859
Nonaccrual			1,106
Current			123,914
Recorded total loans			125,879
Acquired Loans [Member] | Residential [Member] | 31-60 Days Past Due Accruing [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total past due accruing			575
Acquired Loans [Member] | Residential [Member] | 61-90 Days Past Due Accruing [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total past due accruing			20
Acquired Loans [Member] | Residential [Member] | Greater Than 90 Days Past Due Accruing [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total past due accruing			$ 264

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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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No definition available.

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