Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Operating Activities
Net income	$ 73,548	$ 72,100	$ 40,847
Adjustments to reconcile net income to net cash used in operating activities:
Depreciation	9,196	9,519	8,058
Net losses (gains) on sale or disposal of premises and equipment	1,264	992	184
Provision for loan losses	8,364	4,091	5,264
Net write-downs and losses on sale of other real estate owned	500	1,953	15,696
Share-based compensation expense	3,316	2,261	1,485
Amortization of intangible assets	3,932	4,376	3,741
Provision for deferred taxes	12,430	847	(344)
Net amortization of investment securities available for sale	6,384	7,057	5,881
Net gains on securities available for sale	(37)	(94)	(137)
Accretion of discount on purchased loans	(11,308)	(16,637)	(20,248)
Amortization of premium on purchased loan pools	3,543	5,653	1,165
Net amortization (accretion) on other borrowings	95	(76)	0
Amortization of subordinated deferrable interest debentures	1,322	1,453	1,043
Originations of mortgage loans held for sale	(1,502,314)	(1,403,954)	(1,038,691)
Payments received on mortgage loans held for sale	1,238	1,390	1,331
Proceeds from sales of mortgage loans held for sale	1,370,008	1,340,668	989,979
Net gains on mortgage loans held for sale	(46,913)	(52,198)	(40,389)
Originations of SBA loans	(33,104)	(69,512)	(54,594)
Proceeds from sales of SBA loans	30,696	28,268	39,484
Net gains on sales of SBA loans	(4,590)	(3,974)	(4,522)
Increase in cash surrender value of bank owned life insurance	(1,588)	(1,734)	(1,384)
Changes in FDIC loss-share receivable/payable, net of cash payments received	3,005	11,798	5,777
Decrease (increase) in interest receivable	(3,728)	(1,004)	(4,251)
Increase (decrease) in interest payable	1,757	446	(327)
Increase (decrease) in taxes payable	(473)	(8,328)	9,033
Change attributable to other operating activities	10,895	(5,128)	10,696
Net cash used in operating activities	(62,562)	(69,767)	(25,223)
Investing Activities, net of effects of business combinations
Purchases of securities available for sale	(113,261)	(200,823)	(249,115)
Proceeds from prepayments and maturities of securities available for sale	115,166	131,390	89,030
Proceeds from sale of securities available for sale	3,090	75,990	72,528
Net decrease (increase) in other investments	11,046	(17,936)	1,824
Net increase in loans, excluding purchased loans	(1,016,409)	(1,063,345)	(442,180)
Payments received on purchased loans	210,470	247,452	234,038
Purchases of purchased loan pools	0	(152,091)	(622,533)
Payments received on purchased loan pools	112,330	171,087	28,405
Purchases of premises and equipment	(3,760)	(10,977)	(12,576)
Proceeds from sale of premises and equipment	16	295	244
Proceeds from sales of other real estate owned	14,920	22,483	43,269
Purchase of bank owned life insurance	0	0	(4,000)
Payments received from (paid to) FDIC under loss-sharing agreements	(515)	816	19,273
Net cash proceeds received from (paid in) acquisitions	0	(7,206)	673,933
Net cash used in investing activities	(666,907)	(802,865)	(167,860)
Financing Activities, net of effects of business combinations
Net increase (decrease) in deposits	1,050,682	294,513	353,984
Net increase (decrease) in securities sold under agreements to repurchase	(22,867)	(10,080)	(9,725)
Proceeds from other borrowings	1,837,692	635,886	0
Repayment of other borrowings	(2,079,554)	(231,020)	(39,881)
Issuance of common stock	88,656	0	114,889
Proceeds from exercise of stock options	2,669	964	1,191
Dividends paid - common stock	(14,650)	(8,584)	(6,439)
Purchase of treasury shares	(886)	(1,225)	(732)
Net cash provided by financing activities	861,742	680,454	413,287
Net increase (decrease) in cash and cash equivalents	132,273	(192,178)	220,204
Cash and cash equivalents at beginning of period	198,385	390,563	170,359
Cash and cash equivalents at end of period	330,658	198,385	390,563
Cash paid during the year for:
Interest	32,465	19,248	15,183
Income taxes	38,939	40,575	5,828
Loans (excluding purchased loans) transferred to other real estate owned	4,372	3,203	11,261
Purchased loans transferred to other real estate owned	5,023	7,229	12,383
Loans transferred from loans held for sale to loans held for investment	212,850	119,352	71,347
Loans transferred from loans held for investment to loans held for sale	119,389	0	0
Loans provided for the sales of other real estate owned	1,334	1,942	4,826
Assets acquired in business combinations	0	561,440	1,169,990
Liabilities assumed in business combinations	0	465,048	1,099,988
Issuance of common stock in acquisitions	0	72,455	0
Issuance of common stock in exchange for equity investment in US Premium Finance Holding Company	5,844	0	0
Change in unrealized gain (loss) on securities available for sale, net of tax	(338)	(4,435)	(2,389)
Change in unrealized gain (loss) on cash flow hedge, net of tax	$ 116	$ 24	$ (356)