Other Liabilities - Components of Other Liabilities (Detail) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Other Liabilities Disclosure [Abstract]
Deferred compensation	$ 6,431	$ 6,525
Pension liability	27,238	26,645
Joint beneficiary agreements	3,192	3,007
Low income housing tax credit fund commitments	11,439	15,176
Accrued salaries and benefits expense	6,176	5,704
Loan escrow and servicing payable	2,264	2,146
Deferred Revenue	1,759	726
Litigation contingency	1,450	1,450
Miscellaneous other liabilities	2,901	5,985
Total other liabilities	$ 62,850	$ 67,364