Summary of Significant Accounting Policies (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2018 USD ($) Payment Quarter	Dec. 31, 2017 USD ($)
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Equity securities		$ 25,000
Unrealized holding loss on securities		$ (600)
Federal corporate income tax rate	21.00%
Loans [Abstract]
Past due period after which loans must be well secured and in the process of collection to continue accruing interest	90 days
Period of current principal and interest payments for reclassifying nonaccrual loans as accruing loans	6 months
Allowance for Loan and Lease Losses [Abstract]
Number of delinquent monthly payments before loan charge off | Payment	5
Threshold period past due for initiation of foreclosure proceedings	120 days
Current value assessment period for past due loans secured against real estate	90 days
Historical loan loss review period | Quarter	12
Minimum [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Net present value of all potential lease payments	$ 10,100
Other Real Estate Owned [Abstract]
Typical frequency of periodic reviews	12 months
Maximum [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Net present value of all potential lease payments	$ 20,300
Other Real Estate Owned [Abstract]
Typical frequency of periodic reviews	18 months
Frequency of periodic reviews in general	24 months
Commercial [Member] | Unsecured Commercial Loan [Member]
Allowance for Loan and Lease Losses [Abstract]
Charge off threshold for loans considered uncollectible	90 days
Consumer [Member] | Closed-End Consumer Loan [Member]
Allowance for Loan and Lease Losses [Abstract]
Charge off threshold for loans considered uncollectible	120 days
ASU 2017-08 [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Quarterly increase in amortization expense	$ 27