Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	3 Months Ended		12 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Dec. 31, 2018
Operating Activities
Net income	$ 39,905	$ 26,660
Adjustments reconciling net income to net cash provided by (used in) operating activities:
Depreciation	2,623	2,274
Net losses on sale or disposal of premises and equipment including write-downs	348	583
Net write-downs on other assets	571	0
Provision for loan losses	3,408	1,801	$ 16,667
Net losses on sale of other real estate owned including write-downs	9	33
Share-based compensation expense	1,152	1,441
Amortization of intangible assets	3,132	934
Amortization of operating lease right-of-use assets	1,547
Provision for deferred taxes	2,963	2,432
Net amortization of investment securities available for sale	819	1,595
Net gain on securities	(66)	(37)
Accretion of discount on purchased loans	(2,980)	(1,571)
Amortization of premium on purchased loan pools	348	511
Accretion on other borrowings	18	33
Accretion on subordinated deferrable interest debentures	342	331
Originations of mortgage loans held for sale	(296,197)	(358,038)
Payments received on mortgage loans held for sale	194	367
Proceeds from sales of mortgage loans held for sale	305,473	377,748
Net gains on sale of mortgage loans held for sale	(11,484)	(6,759)
Originations of SBA loans	(9,515)	(7,168)
Proceeds from sales of SBA loans	11,870	10,497
Net gains on sale of SBA loans	(1,113)	(918)
Increase in cash surrender value of bank owned life insurance	(501)	(366)
Changes in FDIC loss-share payable, net of cash payments	1,141	785
Change attributable to other operating activities	5,670	(4,671)
Net cash provided by (used in) operating activities	59,677	48,497
Investing Activities, net of effects of business combinations
Proceeds from maturities of time deposits in other banks	3,441	0
Purchases of securities available for sale	(146,874)	(121,865)
Proceeds from prepayments and maturities of securities available for sale	43,942	33,970
Proceeds from sales of securities available for sale	64,995	36,685
Net increase in other investments	(694)	(13,809)
Net increase in loans, excluding purchased loans	(101,360)	(134,063)
Payments received on purchased loans	116,834	43,971
Payments received on purchased loan pools	8,567	16,158
Purchases of premises and equipment	(1,550)	(1,133)
Proceeds from sales of premises and equipment	275	427
Proceeds from sales of other real estate owned	2,610	3,106
Payments paid to FDIC under loss-share agreements	(1,794)	(333)
Net cash and cash equivalents paid in acquisitions	0	(21,421)
Net cash used in investing activities	(11,608)	(158,307)
Financing Activities, net of effects of business combinations
Net increase (decrease) in deposits	151,562	(179,680)
Net decrease in securities sold under agreements to repurchase	(16,125)	(7,368)
Proceeds from other borrowings	0	455,000
Repayment of other borrowings	(338)	(150,052)
Proceeds from exercise of stock options	(54)	(813)
Dividends paid - common stock	(4,751)	(3,726)
Purchase of treasury shares	(998)	(960)
Net cash provided by financing activities	129,404	114,027
Net increase in cash and cash equivalents	177,473	4,217
Cash and cash equivalents at beginning of period	679,527	330,658	330,658
Cash and cash equivalents at end of period	857,000	334,875	$ 679,527
Cash paid during the period for:
Interest	25,741	11,602
Income taxes	49	2
Loans (excluding purchased loans) transferred to other real estate owned	264	1,176
Purchased loans transferred to other real estate owned	2,523	457
Loans transferred from loans held for sale to loans held for investment	0	73,374
Loans transferred from loans held for investment to loans held for sale	0	2,796
Loans provided for the sales of other real estate owned	75	0
Initial recognition of operating lease right-of-use assets	27,286
Initial recognition of operating lease liabilities	29,651
Assets acquired in business acquisitions	1,335	82,981
Liabilities assumed in business acquisitions	(792)	5,705
Issuance of common stock in acquisitions	0	50,011
Change in unrealized gain (loss) on securities available for sale, net of tax	3,821	(9,432)
Change in unrealized gain (loss) on cash flow hedge, net of tax	$ (173)	$ 281