Revenue Recognition - Summary of Noninterest Income Segregated By Revenue Streams (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Noninterest income
Total Noninterest Income	$ 4,390	$ 4,101	$ 10,006	$ 9,237
Noninterest Income (in-scope of Topic 606) [Member]
Noninterest income
Noninterest Income	3,561	3,416	8,521	8,070
Noninterest Income (out-of-scope of Topic 606) [Member]
Noninterest income
Total Noninterest Income	829	685	1,485	1,167
Service Charges [Member]
Noninterest income
Noninterest Income	1,359	1,387	2,493	2,432
Service Charges [Member] | Noninterest Income (in-scope of Topic 606) [Member]
Noninterest income
Noninterest Income	1,359	1,387	2,493	2,432
ATM/Interchange Fees [Member]
Noninterest income
Noninterest Income	588	567	1,142	1,076
ATM/Interchange Fees [Member] | Noninterest Income (in-scope of Topic 606) [Member]
Noninterest income
Noninterest Income	588	567	1,142	1,076
Wealth Management Fees [Member]
Noninterest income
Noninterest Income	836	738	1,688	1,445
Wealth Management Fees [Member] | Noninterest Income (in-scope of Topic 606) [Member]
Noninterest income
Noninterest Income	836	738	1,688	1,445
Tax Refund Processing Fees [Member]
Noninterest income
Noninterest Income	550	550	2,750	2,750
Tax Refund Processing Fees [Member] | Noninterest Income (in-scope of Topic 606) [Member]
Noninterest income
Noninterest Income	550	550	2,750	2,750
Other [Member]
Noninterest income
Noninterest Income	398	238	759	512
Other [Member] | Noninterest Income (in-scope of Topic 606) [Member]
Noninterest income
Noninterest Income	$ 228	$ 174	$ 448	$ 367