Deposits (Detail) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020	Sep. 30, 2020
Balance:
Non-interest-bearing	$ 13,255,417	$ 11,748,455	$ 10,409,747
NOW and interest-bearing demand deposits	3,769,825	3,349,021	3,294,071
Wealth management deposits	4,177,820	4,138,712	4,235,583
Money market	10,757,654	9,348,806	9,423,653
Savings	3,861,296	3,531,029	3,415,073
Time certificates of deposit	4,130,546	4,976,628	5,066,295
Total deposits	$ 39,952,558	$ 37,092,651	$ 35,844,422
Mix:
Non-interest-bearing	33.00%	32.00%	29.00%
NOW and interest-bearing demand deposits	9.00%	9.00%	9.00%
Wealth management deposits	11.00%	11.00%	12.00%
Money market	27.00%	25.00%	26.00%
Savings	10.00%	10.00%	10.00%
Time certificates of deposit	10.00%	13.00%	14.00%
Total deposits	100.00%	100.00%	100.00%