Loans (Additional Information) (Details)	3 Months Ended
	Mar. 31, 2018 USD ($) loan	Mar. 31, 2017 USD ($) loan	Dec. 31, 2017 USD ($)
Accounts, Notes, Loans and Financing Receivable [Line Items]
Number of loans modified as troubled debt restructurings | loan	0	1
Additional lending amount to customers whose loan terms has been modified in troubled debt restructuring	$ 0		$ 0
Increase in allowance for loan losses for troubled debt restructuring loans	0	$ 2,000
Charge-offs due to troubled debt restructurings	$ 0	0
Number of loans modified as troubled debt restructuring subsequently defaulted | loan	0
Threshold amount to individually classify loans by credit risk	$ 250,000
Carrying amount of consumer mortgage loans secured by residential real estate properties	28,000		$ 14,000
Receivables Acquired with Deteriorated Credit Quality
Accounts, Notes, Loans and Financing Receivable [Line Items]
Increase in allowance for loan losses	$ 30,000	11,000
Loans Purchased [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Reversal of allowance for loan losses		$ 0