Other Liabilities - Components of Other Liabilities (Detail) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Other Liabilities Disclosure [Abstract]
Deferred compensation	$ 6,725	$ 7,408
Pension liability	26,182	26,798
Joint beneficiary agreements	2,529	2,728
Low income housing tax credit fund commitments	3,330
Accrued salaries and benefits expense	3,851	5,407
Loan escrow and servicing payable	2,037	1,938
Deferred revenue	1,082	1,091
Unsettled investment security purchases	17,072
Miscellaneous other liabilities	2,485	3,822
Total other liabilities	$ 65,293	$ 49,192