Consolidated Statements of Cash Flows - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018
Cash Flows from Operating Activities
Net income	$ 301,579	$ 240,210
Depreciation, amortization, and accretion, including amortization of purchase accounting adjustments, and market value adjustments	5,638	(1,644)
Adjustments to reconcile net income to net cash provided by operating activities:
Provision for credit losses	33,504	27,290
Share-based compensation expense - equity awards	17,300	15,144
(Gain) loss on sale of OREO and long-lived assets, net of impairment	(1,657)	6,831
Securities losses, net	987	56
(Gain) loss on early termination of FDIC loss share agreements	0	(2,708)
Cash paid for early termination of FDIC loss share agreements	0	(5,637)
Deferred income tax expense	29,407	31,348
Originations of mortgage loans held for sale	(1,443,094)	(1,139,117)
Proceeds from sales of mortgage loans held for sale	1,347,850	1,260,962
Realized and unrealized (gain) on mortgage loans held for sale, net	(52,873)	(35,244)
Other operating activities, net	200,074	(36,390)
Net Cash Provided by Operating Activities	438,715	361,101
Cash Flows from Investing Activities
Proceeds from sales of securities available for sale	299,513	18,867
Proceeds from maturities, prepayments and calls of securities available for sale	549,747	493,095
Purchases of securities available for sale, net of securities available for sale acquired	(199,321)	(711,258)
Proceeds from maturities, prepayments and calls of securities held to maturity	20,353	11,464
Purchases of equity securities, net of equity securities acquired	(15,154)	(21,090)
Proceeds from sales of equity securities	25,741	70,371
Increase in loans, net of loans acquired	(1,135,759)	(767,715)
Proceeds from sales of premises and equipment	1,149	5,698
Purchases of premises and equipment, net of premises and equipment acquired	(17,030)	(11,575)
Proceeds from dispositions of OREO	9,471	12,166
Cash paid for additional investment in tax credit entities	(6,060)	(6,059)
Cash received for acquisition of a business, net of cash paid	0	99,318
Purchase of bank owned life insurance policies	0	(50,000)
Other investing activities, net	999	595
Net Cash Used in Investing Activities	268,116	345,233
Net Cash Provided by (Used in) Investing Activities	(466,351)	(856,123)
Cash Flows from Financing Activities
Increase in deposits, net of deposits acquired	1,213,854	662,680
Net change in short-term borrowings	(984,833)	251,422
Proceeds from long-term debt, net of long-term debt acquired	500,000	927,884
Repayments of long-term debt	(271,562)	(1,361,482)
Cash dividends paid on common stock	(68,667)	(62,937)
Cash dividends paid on preferred stock	(8,146)	(8,146)
Net share-based compensation stock transactions	(4,178)	(3,142)
Payments to repurchase common stock	(204,740)	(61,046)
Net proceeds from issuance of preferred stock	96,388	0
Net Increase (Decrease) In Cash and Cash Equivalents	240,480	(149,789)
Cash and Cash Equivalents at Beginning of Period	690,453	625,724
Cash and Cash Equivalents at End of Period	930,933	475,935
Supplemental Schedule of Non-cash Activities
Acquisition of real estate in settlement of loans	6,023	13,066
Common stock issued in acquisitions	0	214,659
Supplemental Disclosures
Cash paid for interest on deposits and borrowings, net of acquired	235,888	137,727
Cash paid for income taxes	57,287	34,968
Cash received from income tax refunds	$ 178,288	$ 364