Loans and Allowance for Credit Losses - Detail activity in the allowance for credit losses by portfolio segment (Details) - USD ($) $ in Thousands	3 Months Ended
Mar. 31, 2020	Mar. 31, 2019	Dec. 31, 2019
Allowance for Credit Losses, beginning balance	$ 73,658	$ 69,944
Impact of adopting ASC 326	(10,931)		$ 10,614
Loans charged-off	(2,318)	(3,500)
Recoveries of loans previously charged-off	72	139
Net loans charged-off	(2,246)	(3,361)
Provision for credit losses	14,310	3,360
Individually evaluated for impairment	11,833	6,507
Collectively evaluated for impairment	84,503	63,436
Allowance for Credit Losses, ending balance	96,336	69,943
Commercial
Allowance for Credit Losses, beginning balance	18,832	15,857
Impact of adopting ASC 326			892
Loans charged-off		(4)
Recoveries of loans previously charged-off	69	130
Net loans charged-off	69	126
Provision for credit losses	7,553	1,212
Individually evaluated for impairment	7,239	5,892
Collectively evaluated for impairment	20,107	11,303
Allowance for Credit Losses, ending balance	27,346	17,195
Income Producing - Commercial Real Estate
Allowance for Credit Losses, beginning balance	29,265	28,034
Impact of adopting ASC 326			11,230
Loans charged-off	(550)	(3,496)
Net loans charged-off	(550)	(3,496)
Provision for credit losses	3,606	2,227
Individually evaluated for impairment	1,903	15
Collectively evaluated for impairment	41,648	26,750
Allowance for Credit Losses, ending balance	43,551	26,765
Owner Occupied - Commercial Real Estate
Allowance for Credit Losses, beginning balance	5,838	6,242
Impact of adopting ASC 326			4,674
Provision for credit losses	(645)	(262)
Individually evaluated for impairment	375	600
Collectively evaluated for impairment	9,492	5,380
Allowance for Credit Losses, ending balance	9,867	5,980
Real Estate Mortgage Residential
Allowance for Credit Losses, beginning balance	1,557	965
Impact of adopting ASC 326			(301)
Recoveries of loans previously charged-off		1
Net loans charged-off		1
Provision for credit losses	113	(285)
Individually evaluated for impairment	657
Collectively evaluated for impairment	712	681
Allowance for Credit Losses, ending balance	1,369	681
Construction - Commercial and Residential
Allowance for Credit Losses, beginning balance	17,485	18,175
Impact of adopting ASC 326			(6,143)
Loans charged-off	(1,768)
Net loans charged-off	(1,768)
Provision for credit losses	3,767	294
Individually evaluated for impairment	1,554
Collectively evaluated for impairment	11,787	18,469
Allowance for Credit Losses, ending balance	13,341	18,469
Home Equity
Allowance for Credit Losses, beginning balance	656	599
Impact of adopting ASC 326			245
Provision for credit losses	(83)	6
Individually evaluated for impairment	105
Collectively evaluated for impairment	713	605
Allowance for Credit Losses, ending balance	818	605
Other Consumer
Allowance for Credit Losses, beginning balance	25	72
Impact of adopting ASC 326			$ 17
Recoveries of loans previously charged-off	3	8
Net loans charged-off	3	8
Provision for credit losses	(1)	168
Collectively evaluated for impairment	44	248
Allowance for Credit Losses, ending balance	$ 44	$ 248

Amount of recovery of loans and lease receivables which had previously been fully or partially written-off as bad debts.

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Amount of loans and leases that have been written off from both loan receivables and allowance reserve for credit loss.

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Amount, after recoveries, of loans and leases that have been written-off.

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Amount after tax of increase (decrease) to equity or (increase) decrease to net assets, resulting from the cumulative effect adjustment of a new accounting principle applied in the period of adoption.

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

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

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