Consolidated Statements of Cash Flows - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Cash Flows from Operating Activities
Net income	$ 100,131	$ 63,621
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	4,018	(309)
Provision for credit losses	13,763	8,211
Share-based compensation cost - equity awards	5,572	4,734
Loss on sale of OREO and long-lived assets, net of impairment	278	670
Securities loss, net	0	59
Deferred income tax expense	17,861	10,992
Originations of mortgage loans held for sale	(326,244)	(336,400)
Proceeds from sales of mortgage loans held for sale	320,853	367,487
Realized and unrealized (gain) on mortgage loans held for sale, net	(11,593)	(9,320)
Other operating activities, net	152,430	(13,338)
Net Cash Provided by Operating Activities	277,069	96,407
Cash Flows from Investing Activities
Proceeds from maturities, prepayments and calls of available for sale securities	136,627	149,987
Purchases of available for sale securities, net of available for sale securities acquired	(179,565)	(194,543)
Proceeds from maturities, prepayments and calls of held to maturity securities	7,787	2,288
Purchases of equity securities, net of equity securities acquired	(14,753)	(2,452)
Proceeds from sales of equity securities	3,637	61,038
Increase in loans, net of loans acquired	(446,284)	(145,201)
Proceeds from sales of premises and equipment	91	1,408
Purchases of premises and equipment, net of premises and equipment acquired	(3,182)	(5,798)
Proceeds from dispositions of OREO	1,980	5,318
Cash paid for additional investment in tax credit entities	(2,828)	(750)
Cash received (paid) for acquisition of a business, net of cash paid	0	99,312
Other investing activities, net	0	(745)
Net Cash Used in Investing Activities	(496,490)	(30,138)
Cash Flows from Financing Activities
Increase in deposits, net of deposits acquired	328,631	440,470
Net change in short-term borrowings, net of borrowings acquired	(376,751)	(90,802)
Proceeds from long-term debt, net of long-term debt acquired	400,000	200,227
Repayments of long-term debt	(90,560)	(651,684)
Cash dividends paid on common stock	(22,466)	(19,933)
Cash dividends paid on preferred stock	(3,598)	(3,598)
Net share-based compensation stock transactions	(4,445)	(2,581)
Payments to repurchase common stock	(29,946)	0
Net Cash Provided by Financing Activities	200,865	(127,901)
Net Increase (Decrease) In Cash and Cash Equivalents	(18,556)	(61,632)
Cash and Cash Equivalents at Beginning of Period	690,453	625,724
Cash and Cash Equivalents at End of Period	671,897	564,092
Supplemental Schedule of Non-cash Activities
Acquisition of real estate in settlement of loans	2,727	1,757
Common stock issued in acquisitions	0	214,659
Cash paid for:
Interest on deposits and borrowings, net of acquired	71,010	37,035
Income taxes, net	$ 0	$ 101