Business Combination - Schedule of Consideration Paid and Amounts of Assets Acquired and Liabilities Assumed (Detail) - USD ($) $ in Thousands	Jul. 15, 2016	Sep. 30, 2016	Dec. 31, 2015
Recognized amounts of identifiable assets acquired and liabilities assumed:
Goodwill		$ 38,967	$ 27,194
Lake National Bank of Mentor, Ohio [Member]
Consideration paid:
Cash	$ 24,750
Recognized amounts of identifiable assets acquired and liabilities assumed:
Cash and cash equivalents	21,884
Securities available for sale	450
Loans	122,036
FHLB and other equity interests	637
Premises and equipment	3,242
Bank owned life insurance	2,152
Mortgage servicing rights	109
Core deposit intangible	1,583
Accrued interest receivable and other assets	3,301
Total assets acquired	155,394
Demand deposits	81,472
Time deposits	58,311
Accrued interest payable and other liabilities	2,634
Total liabilities assumed	142,417
Total identifiable net assets	12,977
Goodwill	$ 11,773