Allowance for Loan Losses - Summary of Troubled Debt Restructurings (Detail) $ in Thousands		12 Months Ended
		Dec. 31, 2015 USD ($) Loan	Dec. 31, 2014 USD ($) Loan
Accounts, Notes, Loans and Financing Receivable [Line Items]
Subsequently defaulted number of loans | Loan			3
Construction, Land and Land Development
Accounts, Notes, Loans and Financing Receivable [Line Items]
Number of Loans | Loan	[1]		2
Pre-Modification Outstanding Recorded Investment	[1]		$ 282
Post-Modification Outstanding Recorded Investment	[1]		$ 277
Residential Revolving and Junior Mortgages
Accounts, Notes, Loans and Financing Receivable [Line Items]
Number of Loans | Loan	[1]		1
Pre-Modification Outstanding Recorded Investment	[1]		$ 50
Post-Modification Outstanding Recorded Investment	[1]		$ 50
Subsequently defaulted number of loans | Loan			1
Subsequently defaulted recorded investment			$ 75
Commercial Mortgages (Owner Occupied)
Accounts, Notes, Loans and Financing Receivable [Line Items]
Number of Loans | Loan	[2]	1
Pre-Modification Outstanding Recorded Investment	[2]	$ 105
Post-Modification Outstanding Recorded Investment	[2]	$ 124
Subsequently defaulted number of loans | Loan		1	2
Subsequently defaulted recorded investment		$ 124	$ 255
Residential First Mortgages
Accounts, Notes, Loans and Financing Receivable [Line Items]
Number of Loans | Loan	[1]	2
Pre-Modification Outstanding Recorded Investment	[1]	$ 988
Post-Modification Outstanding Recorded Investment	[1]	$ 986

[1] Modifications were an extention of the loan terms.

[2] Modifications were capitalization of the interest.