Summary of Significant Accounting Policies and Recent Accounting Pronouncements (Impact of Adoption Reflected in the Consolidated Balance Sheet) (Details) - USD ($) $ in Thousands	Jan. 01, 2020	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Summary Of Significant Accounting Policies And Recent Accounting Pronouncements [Line Items]
Allowance for loan and lease losses		$ 342,065	$ 450,177	$ 191,251
Reserve for unfunded lending commitments		$ 29,334	$ 29,907	3,974
Allowance for credit losses				$ 195,225
Topic 326 [Member]
Summary Of Significant Accounting Policies And Recent Accounting Pronouncements [Line Items]
Allowance for loan and lease losses	$ 240,662
Reserve for unfunded lending commitments	31,304
Allowance for credit losses	271,966
Topic 326 [Member] | Cumulative Effect, Period of Adoption, Adjustment [Member]
Summary Of Significant Accounting Policies And Recent Accounting Pronouncements [Line Items]
Allowance for loan and lease losses	49,411
Reserve for unfunded lending commitments	27,330
Allowance for credit losses	76,741
Allowance for credit loss increase	76,741
Balance sheet reclassification	(19,767)
Total pretax impact	56,974
Income tax impact	(12,887)
Decrease to retained earnings	$ 44,087