Parent Company Only Financial Statements Parent Company Only Financial Statements, Condensed Balance Sheet Statement (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Assets [Abstract]
Cash and cash equivalents	$ 2,837,410	$ 1,180,573	$ 1,258,821	$ 1,143,424
Loan to bank subsidiary	19,949,259	22,618,880
Other assets	957,951	907,218
Total assets	50,249,431	46,671,088
Liabilities [Abstract]
Other liabilities	435,221	427,213
Subordinated debentures	131,226	276,005
Total liabilities	44,881,060	41,379,527
Shareholders' equity: [Abstract]
Common stock	5	5
Capital surplus	1,378,794	1,368,062
Retained earnings	4,447,691	3,973,675
Treasury Stock, Value	(535,129)	(411,344)
Accumulated other comprehensive income (loss)	72,371	335,868	104,923	(72,585)
Total shareholders’ equity	5,363,732	5,266,266
Total liabilities and shareholders’ equity	50,249,431	46,671,088
Parent Company [Member]
Assets [Abstract]
Cash and cash equivalents	230,647	183,805	$ 214,779	$ 167,093
Loan to bank subsidiary	65,187	65,204
Investment in bank subsidiary	4,951,405	5,079,336
Investment in non-bank subsidiaries	228,447	195,768
Other assets	22,011	24,338
Total assets	5,497,697	5,548,451
Liabilities [Abstract]
Other liabilities	2,739	6,180
Subordinated debentures	131,226	276,005
Total liabilities	133,965	282,185
Shareholders' equity: [Abstract]
Common stock	5	5
Capital surplus	1,378,794	1,368,062
Retained earnings	4,447,691	3,973,675
Treasury Stock, Value	(535,129)	(411,344)
Accumulated other comprehensive income (loss)	72,371	335,868
Total shareholders’ equity	5,363,732	5,266,266
Total liabilities and shareholders’ equity	$ 5,497,697	$ 5,548,451