Note Supplemental disclosure on the consolidated statments of cash flows (Additional disclosures on cash flow information cash and due from banks, and restricted cash) (Detail) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017	Mar. 31, 2017	Dec. 31, 2016
Supplemental Cash Flow Information
Cash and due from banks	$ 265,122		$ 332,505
Restricted cash and due from banks	14,955		7,720
Restricted cash in money market investments	9,804		8,724
Total cash and due from banks, and restricted cash shown in the statement of cash flow	$ 289,881	$ 412,629	$ 348,949	$ 374,196