Consolidated Statements of Cash Flows - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Cash Flows from Operating Activities
Net income	$ 36,425	$ 100,131
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation, amortization, and accretion, including amortization of purchase accounting adjustments and market value adjustments	8,427	4,018
Provision for expected credit losses	68,971	13,763
Share-based compensation expense - equity awards	7,032	5,572
(Gain) loss on sale of OREO and long-lived assets, net of impairment	(956)	278
Deferred income tax expense	8,529	17,861
Originations of mortgage loans held for sale	(533,032)	(326,244)
Proceeds from sales of mortgage loans held for sale	563,199	320,853
Realized and unrealized gain on mortgage loans held for sale, net	(24,656)	(11,593)
Other operating activities, net	(43,782)	152,430
Net Cash Provided by Operating Activities	90,157	277,069
Cash Flows from Investing Activities
Proceeds from maturities, prepayments and calls of securities available for sale	242,074	136,627
Purchases of securities available for sale	(156,706)	(179,565)
Proceeds from maturities, prepayments and calls of securities held to maturity	4,316	7,787
Purchases of equity securities	0	(14,753)
Proceeds from sales of equity securities	0	3,637
Increase in loans	(517,085)	(446,284)
Proceeds from sales of premises and equipment	402	91
Purchases of premises and equipment	(7,065)	(3,182)
Proceeds from dispositions of OREO	12,237	1,980
Cash paid for additional investment in tax credit entities	(673)	(2,828)
Other investing activities, net	(100)	0
Net Cash Used in Investing Activities	(422,600)	(496,490)
Cash Flows from Financing Activities
Increase in deposits	306,888	328,631
Net change in short-term borrowings	186,539	(376,751)
Proceeds from long-term debt	0	400,000
Repayments of long-term debt	(55,430)	(90,560)
Cash dividends paid on common stock	(48,042)	(22,466)
Cash dividends paid on preferred stock	(3,598)	(3,598)
Net share-based compensation stock transactions	(3,575)	(4,445)
Payments to repurchase common stock	0	(29,946)
Net Cash Provided by Financing Activities	382,782	200,865
Net Increase (Decrease) In Cash and Cash Equivalents	50,339	(18,556)
Cash and Cash Equivalents at Beginning of Period	894,723	690,453
Cash and Cash Equivalents at End of Period	945,062	671,897
Supplemental Schedule of Non-cash Activities
Acquisition of real estate in settlement of loans	524	2,727
Supplemental Disclosures
Interest on deposits and borrowings	$ 76,890	$ 71,010