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	Jun. 30, 2018	Dec. 31, 2017	Jun. 30, 2017	Dec. 31, 2016
Supplemental Cash Flow Information
Cash and due from banks	$ 383,518		$ 335,868
Restricted cash and due from banks	17,050		69,820
Restricted cash in money market investments	11,321		8,768
Total cash and due from banks, and restricted cash shown in the statement of cash flow	$ 411,889	$ 412,629	$ 414,456	$ 374,196