Deposits (Detail) - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018	Jun. 30, 2018
Balance:
Non-interest bearing	$ 6,719,958	$ 6,569,880	$ 6,520,724
NOW and interest bearing demand deposits	2,788,976	2,897,133	2,452,474
Wealth management deposits	3,220,256	2,996,764	2,523,572
Money market	6,460,098	5,704,866	5,205,678
Savings	2,823,904	2,665,194	2,763,062
Time certificates of deposit	5,505,623	5,260,841	4,899,969
Total deposits	$ 27,518,815	$ 26,094,678	$ 24,365,479
Mix:
Non-interest bearing	24.00%	25.00%	27.00%
NOW and interest bearing demand deposits	10.00%	11.00%	10.00%
Wealth management deposits	12.00%	12.00%	11.00%
Money market	24.00%	22.00%	21.00%
Savings	10.00%	10.00%	11.00%
Time certificates of deposit	20.00%	20.00%	20.00%
Total deposits	100.00%	100.00%	100.00%