Note Deposits (Total interest bearing deposits) (Detail) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Deposits Abstract
Savings accounts	$ 8,348,091	$ 7,793,533
NOW, money market abd other interest bearing demand deposits	10,838,465	8,012,706
Total savings, NOW, money market and other interest bearing demand deposits	19,186,556	15,806,239
Time Deposits Abstract
Under $100,000	3,549,599	3,570,956
$100,000 and over	4,062,924	4,138,586
Total certificates of deposit	7,612,523	7,709,542
Total interest bearing deposits	$ 26,799,079	$ 23,515,781