Purchased Loans - Narrative (Details)	9 Months Ended
Sep. 30, 2019 USD ($) loan	Sep. 30, 2018 USD ($) loan	Dec. 31, 2018 USD ($)
Loans and Allowance for Loan Losses (Textual) [Abstract]
Allowance for loan losses attributable to restructured loans	$ 50,814,000		$ 49,026,000
Purchased loans
Loans and Allowance for Loan Losses (Textual) [Abstract]
Modifications with subsequent default	$ 0	$ 5,000
Number of restructured loans \| loan	2	3
Restructured loans discontinued past due period	90 days	90 days
Remaining availability under commitments to lend additional funds on restructured loans	$ 5,000	$ 2,000
Purchased loans \| Nonaccruing Loans
Loans and Allowance for Loan Losses (Textual) [Abstract]
Outstanding balance of restructured loans	272,000	503,000
Purchased loans \| Restructured Loans
Loans and Allowance for Loan Losses (Textual) [Abstract]
Outstanding balance of restructured loans	707,000	493,000
Allowance for loan losses attributable to restructured loans	$ 91,000	$ 62,000

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Maximum duration past due for restructured loans to be considered performing.

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Amount of financing receivable modified as troubled debt restructuring within previous 12 months, with subsequent payment default.

+ References

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-Publisher FASB
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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 unfunded portion of contractual agreement to lend funds to borrower for financing receivable modified as troubled debt restructuring.

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

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