Allowance for Loan Losses Allowance by Impairment Analysis Method (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Financing Receivable, Allowance for Credit Losses [Line Items]
Individually Evaluated for Impairment, Recorded Investment	$ 15,643	$ 22,577
Collectively Evaluated for Impairment, Recorded Investment	6,877,515	6,482,451
Total loans	6,893,158	6,505,028
Individually Evaluated for Impairment, Allowance for loan losses	1,235	654
Collectively Evaluated for Impairment, Allowance for loan losses	74,077	74,088
Total allowance for loan losses	75,312	74,742	$ 78,077	$ 78,500
Consumer and other
Financing Receivable, Allowance for Credit Losses [Line Items]
Individually Evaluated for Impairment, Recorded Investment	0	125
Collectively Evaluated for Impairment, Recorded Investment	143,058	177,512
Total loans	143,058	177,637
Individually Evaluated for Impairment, Allowance for loan losses	0	125
Collectively Evaluated for Impairment, Allowance for loan losses	134	505
Total allowance for loan losses	134	630	391
Home equity
Financing Receivable, Allowance for Credit Losses [Line Items]
Individually Evaluated for Impairment, Recorded Investment	2,709	1,815
Collectively Evaluated for Impairment, Recorded Investment	87,712	98,143
Total loans	90,421	99,958
Individually Evaluated for Impairment, Allowance for loan losses	562	20
Collectively Evaluated for Impairment, Allowance for loan losses	722	815
Total allowance for loan losses	1,284	835	1,035
Residential
Financing Receivable, Allowance for Credit Losses [Line Items]
Individually Evaluated for Impairment, Recorded Investment	9,183	10,165
Collectively Evaluated for Impairment, Recorded Investment	2,939,790	2,672,368
Total loans	2,948,973	2,682,533
Individually Evaluated for Impairment, Allowance for loan losses	75	89
Collectively Evaluated for Impairment, Allowance for loan losses	9,951	9,684
Total allowance for loan losses	10,026	9,773	10,449
Construction and land
Financing Receivable, Allowance for Credit Losses [Line Items]
Individually Evaluated for Impairment, Recorded Investment	0	109
Collectively Evaluated for Impairment, Recorded Investment	240,306	164,881
Total loans	240,306	164,990
Individually Evaluated for Impairment, Allowance for loan losses	0	0
Collectively Evaluated for Impairment, Allowance for loan losses	6,022	4,949
Total allowance for loan losses	6,022	4,949	3,039
Commercial real estate
Financing Receivable, Allowance for Credit Losses [Line Items]
Individually Evaluated for Impairment, Recorded Investment	546	8,687
Collectively Evaluated for Impairment, Recorded Investment	2,395,146	2,431,533
Total loans	2,395,692	2,440,220
Individually Evaluated for Impairment, Allowance for loan losses	0	362
Collectively Evaluated for Impairment, Allowance for loan losses	41,934	46,458
Total allowance for loan losses	41,934	46,820	50,412
Commercial and industrial
Financing Receivable, Allowance for Credit Losses [Line Items]
Individually Evaluated for Impairment, Recorded Investment	3,205	1,676
Collectively Evaluated for Impairment, Recorded Investment	1,071,503	938,014
Total loans	1,074,708	939,690
Individually Evaluated for Impairment, Allowance for loan losses	598	58
Collectively Evaluated for Impairment, Allowance for loan losses	15,314	11,677
Total allowance for loan losses	$ 15,912	$ 11,735	$ 12,751

The valuation allowance for financing receivables that are expected to be uncollectible that were collectively evaluated for impairment.

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 11B
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Amount of valuation allowance for financing receivables that are expected to be uncollectible that were individually evaluated for impairment.

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The balance of financing receivables that were collectively evaluated for impairment.

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The balance of financing receivables that were individually evaluated for impairment.

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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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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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