Accounting for Certain Loans Acquired in a Purchase - Narrative (Details) |
12 Months Ended | |
---|---|---|
Dec. 31, 2017
USD ($)
|
Dec. 31, 2016
USD ($)
loan
|
|
Accounts, Notes, Loans and Financing Receivable [Line Items] | ||
Outstanding balance amount of loans acquired | $ 1,302,134,000 | $ 698,097,000 |
Carrying amount of loans acquired | 1,257,617,000 | 665,037,000 |
Loans acquired with deteriorated credit quality | ||
Accounts, Notes, Loans and Financing Receivable [Line Items] | ||
Outstanding balance amount of loans acquired | 38,900,000 | 60,500,000 |
Carrying amount of loans acquired | 25,300,000 | 43,200,000 |
Allowance for loan losses and provision expense | $ 0 | 0 |
Loans acquired with deteriorated credit quality | Transferred to Other Real Estate Owned | ||
Accounts, Notes, Loans and Financing Receivable [Line Items] | ||
Outstanding balance amount of loans acquired | 12,100,000 | |
Carrying amount of loans acquired | $ 7,600,000 | |
Loans transferred to Other Real Estate Owned, number | loan | 1 |