National Commerce Corporation (Parent Company Only) Financial Information - Statements of Earnings (Detail) (USD $)
In Thousands, unless otherwise specified
12 Months Ended
Dec. 31, 2014
Dec. 31, 2013
Dec. 31, 2012
Income tax benefit $ (3,159) $ (2,310) $ (1,071)
Net earnings 5,403 4,006 2,057
Parent Company [Member]      
Income 0 0 0
Other expense 458 123 97
Total expenses 458 123 97
Loss before equity in undistributed earnings of subsidiaries (458) (123) (97)
Equity in undistributed earnings of subsidiaries 5,764 4,079 2,117
Income tax benefit 97 50 37
Net earnings $ 5,403 $ 4,006 $ 2,057