CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018
Cash flows from operating activities:
Net income	$ 118,620	$ 83,697
Adjustments to net income:
Depreciation and amortization expense	7,007	5,487
Provision for credit losses	3,422	5,995
Share-based compensation expense	7,927	6,362
(Gain) loss on sale and disposal of premises and equipment	(152)	52
(Gain) loss on sale of or write down of other real estate owned	(55)	21
Net amortization on securities	3,591	5,326
Net accretion of discounts/premiums for acquired loans and deferred loan fees/costs	(19,982)	(13,362)
Gain on sale of investment securities available-for-sale	(4,900)	(1,399)
Originations of loans held for sale	(83,521)	(82,766)
Proceeds from the sales of and principal payments from loans held for sale	88,683	104,773
Gain on sale of loans	(4,944)	(8,830)
Deferred income tax expense	1,365	(564)
Change in accrued expenses and other liabilities, net	(4,855)	16,343
Income from bank owned life insurance, net	(2,029)	(2,038)
Amortization of core deposit intangible	12,998	8,963
Change in accrued interest receivable and other assets, net	7,858	11,265
Net cash provided by operating activities	131,033	139,325
Cash flows from investing activities:
Net decrease in interest-bearing time deposits with financial institutions	3,432	247
Proceeds from sale of other real estate owned	405	496
Loan originations and payments, net	197,995	(201,021)
Proceeds from loans held for sale previously classified as portfolio loans	76,579	21,556
Purchase of loans held for investment	(182,504)	(61,562)
Purchase of held-to-maturity securities	0	(29,002)
Principal payments on held-to-maturity securities	4,741	839
Purchase of securities available-for-sale	(603,457)	(390,459)
Principal payments on securities available-for-sale	85,330	103,179
Proceeds from sale or maturity of securities available-for-sale	418,471	394,536
Proceeds from the sale of premises and equipment	11,139	0
Proceeds from bank owned life insurance death benefit	405	0
Purchases of premises and equipment	(16,154)	(9,365)
Change in FHLB, FRB, and other stock, at cost	2,381	(20,954)
Funding of CRA investments	(7,295)	(13,703)
Change in cash acquired in acquisitions, net	0	146,571
Net cash used in investing activities	(8,532)	(58,642)
Cash flows from financing activities:
Net increase in deposit accounts	200,937	(90,671)
Net change in short-term borrowings	(53,075)	86,211
Repayment of long-term FHLB borrowings	(10,000)	(10,500)
Redemption of junior subordinated debt securities	(15,465)	0
Proceeds from issuance of subordinated debt, net	122,453	0
Cash dividends paid	(40,807)	0
Repurchase and retirement of common stock	(100,000)	0
Proceeds from exercise of stock options	394	1,911
Restricted stock surrendered and canceled	(2,629)	(1,586)
Net cash provided by (used in) financing activities	101,808	(14,635)
Net increase in cash and cash equivalents	224,309	66,048
Cash and cash equivalents, beginning of period	203,406	197,164
Cash and cash equivalents, end of period	427,715	263,212
Supplemental cash flow disclosures:
Interest paid	58,591	33,290
Income taxes paid	33,469	27,806
Noncash investing activities during the period:
Transfers from portfolio loans to loans held for sale	78,085	64,187
Transfers from loans to other real estate owned	329	15
Recognition of operating lease right-of-use assets	(49,542)	0
Recognition of operating lease liabilities	49,542	0
Due on unsettled security purchases	(2,034)	(9,988)
Assets acquired (liabilities assumed and capital created) in acquisitions (See Note 4):
Investment securities	0	392,858
FHLB and other stock	0	16,768
Loans	0	2,352,388
Core deposit intangible	0	71,943
Deferred income tax	0	4,536
Goodwill	0	312,239
Fixed assets	0	9,122
Other assets	0	80,478
Deposits	0	(2,506,929)
Other borrowings	0	(254,923)
Other liabilities	0	(24,859)
Common stock and additional paid-in capital	$ 0	$ (601,172)