CONSOLIDATED BALANCE SHEETS (Unaudited) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Assets [Abstract]
Cash and noninterest-bearing due from banks	$ 179,231	$ 157,901
Restricted Cash, Current	247,761	137,045
Interest-bearing due from banks	2,604,646	210,784
Federal funds sold and other	11,687	20,977
Cash and cash equivalents	3,043,325	526,707
Available-for-sale Securities	3,463,422	3,539,995
Securities held-to-maturity (fair value of $1.1 billion, net of allowance for credit losses of $191,000 at Sept. 30, 2020 and $201.2 million at Dec. 31., 2019, respectively)	1,039,650	188,996
Consumer loans held-for-sale	82,748	81,820
Commercial loans held-for-sale	12,290	17,585
Loans and Leases Receivable, Net of Deferred Income	22,477,409	19,787,876
Less allowance for credit losses	(288,645)	(94,777)
Loans, net	22,188,764	19,693,099
Premises and equipment, net	287,711	273,932
Equity method investment	289,301	278,037
Accrued interest receivable	101,762	84,462
Goodwill	1,819,811	1,819,811
Core deposits and other intangible assets	44,713	51,130
Other real estate owned	19,445	29,487
Other assets	1,431,989	1,220,435
Total assets	33,824,931	27,805,496
Deposits:
Noninterest-bearing	7,050,670	4,795,476
Interest-bearing	4,995,769	3,630,168
Savings and money market accounts	10,513,645	7,813,939
Time	3,983,872	3,941,445
Total deposits	26,543,956	20,181,028
Securities sold under agreements to repurchase	127,059	126,354
Federal Home Loan Bank advances	1,287,738	2,062,534
Subordinated debt and other borrowings	670,273	749,080
Accrued interest payable	26,101	42,183
Other liabilities	382,496	288,569
Total liabilities	29,037,623	23,449,748
Shareholders' equity:
Preferred stock, no par value, 10.0 million shares authorized; 225,000 shares non-cumulative perpetual preferred stock, Series B, liquidation preference $225.0 million, issued and outstanding at Sept. 30, 2020 and no shares issued and outstanding at Dec. 31, 2019, respectively.	217,126	0
Common stock, par value $1.00; 180.0 million shares authorized; 75.8 million and 76.6 million shares issued and outstanding at Sept. 30, 2020 and Dec. 31, 2019, respectively	75,835	76,564
Additional paid-in capital	3,023,430	3,064,467
Retained earnings	1,312,929	1,184,183
Accumulated other comprehensive income, net of taxes	157,988	30,534
Total shareholders' equity	4,787,308	4,355,748
Liabilities and Equity	$ 33,824,931	$ 27,805,496