Note Deposits (Total interest bearing deposits) (Detail) - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016
Deposits Abstract
Savings accounts	$ 7,946,021	$ 7,793,533
NOW, money market abd other interest bearing demand deposits	10,138,090	8,012,706
Total savings, NOW, money market and other interest bearing demand deposits	18,084,111	15,806,239
Time Deposits Abstract
Under $100,000	3,542,057	3,570,956
$100,000 and over	4,014,133	4,138,586
Total certificates of deposit	7,556,190	7,709,542
Total interest bearing deposits	$ 25,640,301	$ 23,515,781