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

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Amount of allowance for credit loss for debt security measured at amortized cost (held-to-maturity).

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Amount of expense (reversal of expense) for expected credit loss on investment in debt security measured at amortized cost (held-to-maturity).

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Amount of allowance for credit loss on financing receivable. Excludes allowance for financing receivable covered under loss sharing agreement.

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Amount, before troubled debt restructuring, of financing receivable to be modified.

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Amount of financing receivable on nonaccrual status with no allowance for credit loss.

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Amount of expense related loan transactions, lease transactions, credit loss from transactions other than loan and lease transactions, and other loss based on assessment of uncollectability from the counterparty to reduce the account to their net realizable value.

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Allowance for Credit Losses (Allowance for Credit Losses Narrative) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019	Jan. 01, 2020	Dec. 31, 2019	Dec. 31, 2018
Financing Receivable, Allowance for Credit Loss [Line Items]
Nonaccrual loans with no related allowance for credit losses	$ 75,000
Loans reasonably expected to be modified into TDRs	8,300
Allowance for loan losses	253,412	$ 159,622		$ 158,461	$ 154,164
Provision for credit losses	52,961	10,624
Loan net charge-offs	5,300
Allowance for held-to-maturity securities losses	70	0		0
Held-to-maturity securities, provision (reversal) for credit losses	(4)
Cumulative effect adjustment from the adoption of ASU 2016-13
Financing Receivable, Allowance for Credit Loss [Line Items]
Allowance for loan losses			$ 47,300	47,344
Allowance for held-to-maturity securities losses			74
Loans acquired with deteriorated credit quality
Financing Receivable, Allowance for Credit Loss [Line Items]
Allowance for loan losses		644
Loans acquired with deteriorated credit quality \| Cumulative effect adjustment from the adoption of ASU 2016-13
Financing Receivable, Allowance for Credit Loss [Line Items]
Allowance for loan losses			11,000
Loans acquired without deteriorated credit quality \| Cumulative effect adjustment from the adoption of ASU 2016-13
Financing Receivable, Allowance for Credit Loss [Line Items]
Allowance for loan losses			3,200
Unfunded lending-related commitments
Financing Receivable, Allowance for Credit Loss [Line Items]
Allowance for loan losses	37,362	1,410		1,633
Unfunded lending-related commitments \| Cumulative effect adjustment from the adoption of ASU 2016-13
Financing Receivable, Allowance for Credit Loss [Line Items]
Allowance for loan losses			33,200
Loans
Financing Receivable, Allowance for Credit Loss [Line Items]
Allowance for loan losses	$ 216,050	$ 158,212		$ 156,828
Loans \| Cumulative effect adjustment from the adoption of ASU 2016-13
Financing Receivable, Allowance for Credit Loss [Line Items]
Allowance for loan losses			$ 14,200