Consolidated Balance Sheets - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Assets
Cash and due from banks	$ 410,495	$ 362,048
Overnight investments	7,588,757	4,347,336
Investment in marketable equity securities	106,886	91,680
Debt Securities, Available-for-sale	7,307,122	7,014,243
Investment securities held to maturity at cost	2,808,099	2,816,982
Loans held for sale	129,334	124,837
Loans and leases	33,180,851	32,791,975
Allowance for loan and lease losses	(210,651)	(224,314)
Net loans and leases	32,970,200	32,567,661
Premises and equipment	1,238,874	1,251,283
Other real estate owned	48,512	50,890
Income earned not collected	148,022	145,694
Goodwill	350,298	350,298
Other intangible assets	51,547	50,775
Other assets	750,460	783,953
Total assets	53,908,606	49,957,680
Deposits [Abstract]
Noninterest-bearing deposits	20,515,142	18,014,029
Interest-bearing deposits	26,815,855	25,417,580
Total deposits	47,330,997	43,431,609
Securities sold under customer repurchase agreements	680,705	641,487
Federal Home Loan Bank borrowings	648,671	655,175
Subordinated Debt	497,153	504,518
Other Borrowings	84,502	88,470
FDIC shared-loss payable	0	15,601
Other liabilities	345,178	391,552
Total liabilities	49,587,206	45,728,412
Shareholders' Equity
Preferred stock	339,937	339,937
Retained earnings	4,005,318	3,867,252
Accumulated other comprehensive loss	(33,671)	12,263
Total shareholders' equity	4,321,400	4,229,268
Total liabilities and shareholders' equity	$ 53,908,606	$ 49,957,680
Preferred stock, shares issued	345,000	345,000
Preferred stock, shares outstanding	345,000	345,000
Class A Common Stock
Shareholders' Equity
Common stock	$ 8,811	$ 8,811
Common stock, shares issued	8,811,220	8,811,220
Common stock, shares outstanding	8,811,220	8,811,220
Class B Common Stock
Shareholders' Equity
Common stock	$ 1,005	$ 1,005
Common stock, shares issued	1,005,185	1,005,185
Common stock, shares outstanding	1,005,185	1,005,185