CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Cash flows from operating activities:
Net income	$ 123,340	$ 60,100	$ 40,103
Adjustments to net income:
Depreciation and amortization expense	7,773	4,888	2,854
Provision for credit losses	8,253	8,432	9,296
Share-based compensation expense	9,033	5,809	2,729
Loss on sale and disposal of premises and equipment	108	234	656
(Gain) loss on sale of or write down of other real estate owned	(355)	(46)	321
Net amortization on securities	6,900	7,601	9,157
Net accretion of discounts/premiums for loans acquired and deferred loan fees/costs	4,224	1,627	1,832
Gain on sale of investment securities available-for-sale	(1,399)	(2,737)	(1,797)
Other-than-temporary impairment recovery on investment securities, net	0	0	(205)
Originations of loans held for sale	(174,718)	(142,104)	(103,883)
Proceeds from the sales of and principal payments from loans held for sale	309,706	140,012	115,877
Gain on sale of loans	(10,759)	(12,468)	(9,539)
Deferred income tax expense	9,275	16,866	3,887
Change in accrued expenses and other liabilities, net	1,388	5,193	(4,948)
Income from bank owned life insurance, net	(2,774)	(1,842)	(1,164)
Amortization of core deposit intangible	13,594	6,144	2,039
Change in accrued interest receivable and other assets, net	(4,901)	(13,932)	(3,768)
Net cash (used in) provided by operating activities	298,688	83,777	63,447
Cash flows from investing activities:
Net increase in interest-bearing time deposits with financial institutions	490	(2,689)	0
Increase in loans, net	(338,671)	(519,163)	(263,075)
Purchase of loans held for investment	(61,562)	(13,582)	(271,159)
Proceeds from sale of other real estate owned	1,058	507	380
Purchase of held-to-maturity securities	(29,002)	(10,914)	0
Principal payments on held-to-maturity securities	1,785	1,166	1,060
Purchase of securities available-for-sale	(462,534)	(306,527)	(190,140)
Principal payments on securities available for sale	131,268	74,891	37,875
Proceeds from sale of securities available-for-sale	407,004	268,596	230,945
Proceeds from the sale of premises and equipment	0	0	10,049
Proceeds from bank owned insurance death benefit	1,284	198	0
Purchases of premises and equipment	(10,295)	(4,165)	(11,970)
Change in FHLB, FRB, and other stock, at cost	(27,086)	(12,838)	(15,012)
Cash acquired in acquisitions, net	146,571	225,945	40,132
Net cash used in investing activities	(239,690)	(298,575)	(430,915)
Cash flows from financing activities:
Net increase in deposit accounts	65,553	187,901	313,770
Net change in short-term borrowings	(108,064)	61,120	181,846
Proceeds from long-term borrowings	0	12,012	0
Repayment of long-term borrowings	(10,500)	(9,262)	(50,927)
Proceeds from exercise of stock options and warrants	1,924	4,592	1,345
Restricted stock surrendered and canceled	(1,669)	(1,258)	(126)
Net cash (used in) provided by financing activities	(52,756)	255,105	445,908
Net change in cash and cash equivalents	6,242	40,307	78,440
Cash and cash equivalents, beginning of year	197,164	156,857	78,417
Cash and cash equivalents, end of year	203,406	197,164	156,857
Supplemental cash flow disclosures:
Interest paid	53,960	21,777	13,564
Income taxes paid	32,296	18,846	13,139
NONCASH INVESTING ACTIVITIES DURING THE PERIOD
Transfers from loans to other real estate owned	15	121	197
Loans held for sale transfer to loans held for investment	337	949	1,274
Assets acquired (liabilities assumed) in acquisitions (See Note 26):
Interest-bearing deposits with financial institutions	0	0	1,972
Investment securities	392,858	442,923	190,254
Loans	2,352,717	2,427,589	456,158
Core deposit intangible	71,943	39,703	4,319
Deferred income tax	4,383	14,959	6,748
Goodwill	313,043	391,070	51,658
Fixed assets	9,122	42,097	4,190
Other assets	97,246	74,379	9,362
Deposits	(2,506,929)	(2,752,501)	(636,591)
Other borrowings	(254,923)	(180,186)	0
Other liabilities	(24,859)	(16,395)	(8,843)
Common Stock and additional paid-in capital	$ (601,172)	$ (716,421)	$ (120,174)