Condensed Financial Information Of Parent Company Condensed Financial Information Of Parent Company (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Condensed Financial Statements, Captions [Line Items]
Other assets	$ 636,811	$ 540,385
Total assets	26,770,806	25,731,354
Subordinated debentures	458,209	453,846
Total liabilities	21,816,109	20,905,766
Stockholders' Equity Attributable to Parent Only	4,954,697	4,825,588	$ 4,977,598	$ 4,479,055
Total liabilities and stockholders' equity	26,770,806	25,731,354
Parent [Member]
Condensed Financial Statements, Captions [Line Items]
Cash	113,961	244,859
Investments In Consolidated Banking Subsidiaries	4,905,033	4,641,649
Other assets	74,479	79,516
Total assets	5,093,473	4,966,024
Subordinated debentures	135,055	135,055
Other Liabilities	3,721	5,381
Total liabilities	138,776	140,436
Stockholders' Equity Attributable to Parent Only	4,954,697	4,825,588
Total liabilities and stockholders' equity	$ 5,093,473	$ 4,966,024