Acquisitions - Pro Forma Result of Comparable Prior Reporting Period (Detail) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Business Acquisition, Pro Forma Information [Abstract]
Net Interest Income	$ 27,198	$ 25,876	$ 52,766	$ 51,373
Provision for Loan Losses	330	232	660	764
Net Interest Income after Provision for Loan Losses	26,868	25,644	52,106	50,609
Non-interest Income	8,212	13,020	15,771	21,493
Non-Interest Expense	22,488	27,067	44,009	51,975
Income before Income Taxes	12,592	11,597	23,868	20,127
Income Tax Expense	3,520	1,028	6,572	3,413
Net Income	9,072	10,569	17,296	16,714
Net Income Available to Common Shareholders	$ 9,072	$ 10,569	$ 17,296	$ 16,672
Basic Earnings Per Share	$ 0.41	$ 0.58	$ 0.78	$ 0.92
Diluted Earnings Per Share	$ 0.41	$ 0.58	$ 0.77	$ 0.92