CONSOLIDATED STATEMENTS OF CASH FLOWS (unaudited) - USD ($) $ in Thousands		3 Months Ended
		Mar. 31, 2020	Mar. 31, 2019
Operating Activities
Net income		$ 38,521	$ 120,186
Adjustments to reconcile net income to net cash provided by operating activities:
Provision for credit losses	[1]	158,722	23,569
Depreciation, amortization, and accretion, net		23,649	7,000
Deferred income tax (benefit) expense		(10,978)	6,915
Originations of mortgage loans held for sale		(254,395)	(120,207)
Proceeds from sales of mortgage loans held for sale		259,224	104,552
Gain on sales of mortgage loans held for sale, net		(9,497)	(3,534)
(Increase) decrease in other assets		(442,711)	21,634
Increase (decrease) in other liabilities		260,486	(27,776)
Investment securities gains, net		(8,734)	(75)
Loss on early extinguishment of debt		1,904	0
Share-based compensation expense		3,570	10,244
Net cash provided by operating activities		19,761	142,508
Investing Activities
Net cash received in business combination, net of cash paid		0	201,100
Proceeds from maturities and principal collections of investment securities available for sale		341,431	197,726
Proceeds from sales of investment securities available for sale		413,180	1,642,239
Purchases of investment securities available for sale		(755,558)	(2,254,346)
Proceeds from sales of loans		11,808	13,654
Proceeds from sales of other real estate and other assets		8,547	6,273
Net increase in loans		(1,065,125)	(423,514)
Net (purchases) redemptions of Federal Home Loan Bank stock		(978)	1,285
Net (purchases) redemptions of Federal Reserve Bank stock		(454)	(24,239)
Net (purchases) proceeds from settlement of bank-owned life insurance policies		(249,942)	656
Net increase in premises and equipment		(6,941)	(9,209)
Net cash used in investing activities		(1,304,032)	(648,375)
Financing Activities
Net increase in deposits		1,420,659	434,677
Net increase in federal funds purchased and securities sold under repurchase agreements		147,086	47,552
Net change in other short-term borrowings		(578,560)	203,000
Repayments and redemption of long-term debt		(251,904)	0
Proceeds from issuance of long-term debt, net		1,248,441	297,045
Dividends paid to common shareholders		(44,149)	(28,966)
Dividends paid to preferred shareholders		(3,150)	(3,150)
Stock options and warrants exercised		6,267	6,649
Repurchase of common stock		(16,246)	(320,167)
Taxes paid related to net share settlement of equity awards		(7,257)	(8,412)
Net cash provided by financing activities		1,921,187	628,228
Increase in cash and cash equivalents including restricted cash		636,916	122,361
Cash, cash equivalents, restricted cash, and restricted cash equivalents at beginning of period		1,186,918	1,143,564
Cash, cash equivalents, restricted cash, and restricted cash equivalents at end of period		1,823,834	1,265,925
Supplemental Disclosures:
Income taxes paid		920	1,050
Interest paid		109,340	95,630
Non-cash Activities
Common stock issued, treasury stock reissued, equity awards/warrants exchanged to acquire FCB		0	1,625,688
Securities sold during the period but settled after period-end		169,748	0
Securities purchased during the period but settled after period-end		113,818	0
Premises and equipment transferred to other assets held for sale		4,681	785
Loans foreclosed and transferred to other real estate		1,951	1,419
Loans transferred to/(from) other loans held for sale at fair value		11,893	12,237
Dividends declared on common stock during the period but paid after period-end		48,598	47,235
Dividends declared on preferred stock during the period but paid after period-end		$ 5,141	$ 0

[1] Beginning January 1, 2020, provision calculation is based on current expected loss methodology. Prior to January 1, 2020, calculation was based on incurred loss methodology.