Parent Company Information - Schedule of Condensed Statements of Financial Condition (Detail) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Assets
Other assets	$ 717,600	$ 659,721
Total Assets	37,436,020	31,863,088
Liabilities and Shareholders’ Equity
Junior subordinated debentures issued to capital trusts	55,718	55,370
Shareholders’ equity	4,384,188	3,350,454	$ 2,533,165	$ 2,377,156
Total Liabilities and Shareholders’ Equity	37,436,020	31,863,088
Parent Company
Assets
Cash	119,213	109,839
Investments in and receivables due from subsidiaries	4,671,578	3,609,836
Other assets	12,953	32,721
Total Assets	4,803,744	3,752,396
Liabilities and Shareholders’ Equity
Dividends payable to shareholders	45,796	37,644
Long-term borrowings	292,414	294,602
Junior subordinated debentures issued to capital trusts	55,718	55,370
Accrued expenses and other liabilities	25,628	14,326
Shareholders’ equity	4,384,188	3,350,454
Total Liabilities and Shareholders’ Equity	$ 4,803,744	$ 3,752,396