Significant Accounting Policies - Additional Cash Flow Information (Detail) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015
Accounting Policies [Abstract]
Cash paid for interest	$ 8,731	$ 9,906
Cash paid for income taxes	39,160	35,300
Securities purchased not yet settled	54,342	3,428
Loans foreclosed and transferred to other real estate owned and foreclosed assets	422	826
Loans to facilitate the sale of other real estate owned	$ 0	$ 20