Consolidated Statements of Cash Flows - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017
Cash Flows from Operating Activities
Net income	$ 240,210	$ 132,135
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	(1,644)	1,060
Provision for loan and lease losses	26,678	36,718
Share-based compensation cost - equity awards	15,144	11,499
Loss (gain) on sale of OREO and long-lived assets, net of impairment	6,831	675
Loss (gain) on sale of available for sale securities	56	183
(Gain) loss on early termination of FDIC loss share agreements	(2,708)	0
Cash paid for early termination of FDIC loss share agreements	(5,637)	0
Expense (benefit) for deferred income taxes	31,348	12,438
Originations of mortgage loans held for sale	(1,139,117)	(1,415,447)
Proceeds from sales of mortgage loans held for sale	1,260,962	1,475,038
Realized and unrealized (gain) loss on mortgage loans held for sale, net	(35,244)	(48,944)
Other operating activities, net	(35,778)	14,062
Net Cash Provided by Operating Activities	361,101	219,417
Cash Flows from Investing Activities
Proceeds from sales of available for sale securities	18,867	577,891
Proceeds from maturities, prepayments and calls of available for sale securities	493,095	410,419
Purchases of available for sale securities, net of available for sale securities acquired	(711,258)	(1,312,762)
Proceeds from maturities, prepayments and calls of held to maturity securities	11,464	6,714
Purchases of held to maturity securities	0	(94,179)
Purchases of equity securities, net of equity securities acquired	(21,090)	(40,749)
Proceeds from sales of equity securities	70,371	6,119
Increase in loans, net of loans acquired	(767,715)	(699,684)
Proceeds from sales of premises and equipment	5,698	2,750
Purchases of premises and equipment, net of premises and equipment acquired	(11,575)	(31,522)
Proceeds from dispositions of OREO	12,166	11,653
Cash paid for additional investment in tax credit entities	(6,059)	(7,160)
Cash received (paid) for acquisition of a business, net of cash paid	99,318	(490,509)
Purchase of bank owned life insurance policies	(50,000)	0
Other investing activities, net	595	893
Net Cash Used in Investing Activities	(856,123)	(1,660,126)
Cash Flows from Financing Activities
Increase (decrease) in deposits, net of deposits acquired	662,680	(456,350)
Net change in short-term borrowings, net of borrowings acquired	251,422	494,029
Proceeds from long-term debt, net of long-term debt acquired	927,884	516,620
Repayments of long-term debt	(1,361,482)	(17,342)
Cash dividends paid on common stock	(62,937)	(52,841)
Cash dividends paid on preferred stock	(8,146)	(8,146)
Net share-based compensation stock transactions	(3,142)	(1,922)
Payments to repurchase common stock	(61,046)	0
Net proceeds from issuance of common stock	0	485,751
Net Cash Provided by Financing Activities	345,233	959,799
Net Increase (Decrease) In Cash and Cash Equivalents	(149,789)	(480,910)
Cash and Cash Equivalents at Beginning of Period	625,724	1,362,126
Cash and Cash Equivalents at End of Period	475,935	881,216
Supplemental Schedule of Non-cash Activities
Acquisition of real estate in settlement of loans	13,066	6,873
Common stock issued in acquisitions	214,659	211,043
Cash paid for:
Interest on deposits and borrowings, net of acquired	137,727	69,057
Income taxes, net	$ 34,604	$ 67,434