XML 148 R134.htm IDEA: XBRL DOCUMENT v3.6.0.2
Regulatory Requirements and Restrictions - Additional Information (Detail)
Jan. 01, 2016
Dec. 31, 2016
Dec. 31, 2015
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]      
Capital conservation buffer, phased period 4 years    
First Community Bank      
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]      
Capital conservation buffer, risk-weighted assets ratio [1]   5.00% 5.00%
On January 1, 2016      
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]      
Capital conservation buffer, risk-weighted assets ratio 0.625%    
On January 1, 2019      
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]      
Capital conservation buffer, risk-weighted assets ratio 2.50%    
Basel III Fully Phased-In | First Community Bancshares, Inc.      
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]      
Capital conservation buffer, risk-weighted assets ratio   5.29%  
Basel III Fully Phased-In | First Community Bank      
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]      
Capital conservation buffer, risk-weighted assets ratio   3.48%  
[1] Based on prompt corrective action provisions