CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Dec. 31, 2018	Mar. 31, 2018
Cash flows from operating activities:
Net income	$ 38,718	$ 39,643	$ 28,002
Adjustments to net income:
Depreciation and amortization expense	2,259		1,657
Provision for credit losses	1,526	2,258	2,253
Share-based compensation expense	2,453		1,712
Loss on sale and disposal of premises and equipment	64		0
Loss on sale of or write down of other real estate owned	0		12
Net amortization on securities	1,453		1,645
Net accretion of deferred loan fees/costs and discounts/premiums for loans acquired	5,723		(1,566)
Gain on sale of investment securities available-for-sale	(427)	0	(6)
Originations of loans held for sale	(31,762)		(29,229)
Proceeds from the sales of and principal payments from loans held for sale	27,623		38,814
Gain on sale of loans	(1,729)		(2,958)
Deferred income tax expense	1,995		2,750
Change in accrued expenses and other liabilities, net	(11,956)		(11,305)
Income from bank owned life insurance, net	(713)		(478)
Amortization of core deposit intangible	4,436		2,274
Change in accrued interest receivable and other assets, net	12,621		1,293
Net cash provided by operating activities	52,284		34,870
Cash flows from investing activities:
Net decrease in interest-bearing time deposits with financial institutions	247		0
Proceeds from sale of other real estate owned	0		108
Increase in loans, net	(35,106)		(44,531)
Purchase of held-to-maturity securities	0		(6,367)
Principal payments on held-to-maturity securities	1,310		78
Purchase of securities available-for-sale	(226,836)		(117,407)
Principal payments on securities available-for-sale	(28,404)		(26,768)
Proceeds from sale or maturity of securities available-for-sale	168,837		0
Proceeds from the sale of premises and equipment	2,650		0
Proceeds from bank owned life insurance death benefit	220		0
Purchases of premises and equipment	(1,805)		(1,647)
Change in FHLB, FRB, and other stock, at cost	488		(16,234)
Net cash used in investing activities	(61,591)		(159,232)
Cash flows from financing activities:
Net increase in deposit accounts	56,823		106,405
Net change in short-term borrowings	(53,075)		(42,279)
Repayment of long-term FHLB borrowings	(5,000)		(10,418)
Cash dividends paid	(13,749)		0
Proceeds from exercise of stock options and warrants	331		1,084
Restricted stock surrendered and canceled	(1,047)		(1,538)
Net cash (used in) provided by financing activities	(15,717)		53,254
Net decrease in cash and cash equivalents	(25,024)		(71,108)
Cash and cash equivalents, beginning of period	203,406		197,164
Cash and cash equivalents, end of period	178,382	$ 203,406	126,056
Supplemental cash flow disclosures:
Interest paid	18,519		9,974
Income taxes paid	53		95
Noncash investing activities during the period:
Transfers from loans to other real estate owned	34		0
Receivable on unsettled security sales	1,061		0
Due on unsettled security purchases	(25,657)		0
Initial recognition of operating lease right-of-use assets	(45,675)		0
Initial recognition of operating lease liabilities	$ 45,675		$ 0