Allowance for Loan Losses Allowance Rollforward (Details) - USD ($) $ in Thousands	3 Months Ended
Mar. 31, 2019	Mar. 31, 2018
Allowance for Loan and Lease Losses [Roll Forward]
Allowance for loan losses, beginning of period:	$ 75,312	$ 74,742
Loans charged-off:	(564)	(389)
Recoveries on loans previously charged-off:	492	340
Provision/ (credit) for loan losses	(1,426)	(1,795)
Allowance for loan losses at end of period:	73,814	72,898
Commercial and industrial
Allowance for Loan and Lease Losses [Roll Forward]
Allowance for loan losses, beginning of period:	15,912	11,735
Loans charged-off:	0	(214)
Recoveries on loans previously charged-off:	188	82
Provision/ (credit) for loan losses	(413)	(160)
Allowance for loan losses at end of period:	15,687	11,443
Commercial real estate
Allowance for Loan and Lease Losses [Roll Forward]
Allowance for loan losses, beginning of period:	41,934	46,820
Loans charged-off:	0	(135)
Recoveries on loans previously charged-off:	189	125
Provision/ (credit) for loan losses	(310)	(694)
Allowance for loan losses at end of period:	41,813	46,116
Construction and land
Allowance for Loan and Lease Losses [Roll Forward]
Allowance for loan losses, beginning of period:	6,022	4,949
Loans charged-off:	0	0
Recoveries on loans previously charged-off:	0	0
Provision/ (credit) for loan losses	(669)	(416)
Allowance for loan losses at end of period:	5,353	4,533
Residential
Allowance for Loan and Lease Losses [Roll Forward]
Allowance for loan losses, beginning of period:	10,026	9,773
Loans charged-off:	0	(16)
Recoveries on loans previously charged-off:	100	0
Provision/ (credit) for loan losses	(69)	139
Allowance for loan losses at end of period:	10,057	9,896
Home equity
Allowance for Loan and Lease Losses [Roll Forward]
Allowance for loan losses, beginning of period:	1,284	835
Loans charged-off:	(562)	0
Recoveries on loans previously charged-off:	0	1
Provision/ (credit) for loan losses	74	(52)
Allowance for loan losses at end of period:	796	784
Consumer and other
Allowance for Loan and Lease Losses [Roll Forward]
Allowance for loan losses, beginning of period:	134	630
Loans charged-off:	(2)	(24)
Recoveries on loans previously charged-off:	15	132
Provision/ (credit) for loan losses	(39)	(612)
Allowance for loan losses at end of period:	$ 108	$ 126

A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

No definition available.

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- Definition

Amount of recovery of financing receivables doubtful of collection that were previously charged off.

+ References

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- Definition

Amount of direct write-downs of financing receivables charged against the allowance.

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- Definition

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.

+ References

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- Definition

Amount of expense related to estimated loss from loan and lease transactions.

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