Consolidated Statements of Income and Comprehensive Income (Unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Interest income
Interest and fees on loans	$ 110,470	$ 70,462	$ 266,460	$ 197,447
Interest on taxable securities	8,792	5,062	20,320	15,057
Interest on nontaxable securities	204	392	705	1,209
Interest on deposits in other banks and federal funds sold	1,653	406	3,092	1,070
Total interest income	121,119	76,322	290,577	214,783
Interest expense
Interest on deposits	15,630	5,136	30,196	13,479
Interest on other borrowings	6,451	4,331	16,543	10,702
Total interest expense	22,081	9,467	46,739	24,181
Net interest income	99,038	66,855	243,838	190,602
Provision for loan losses	2,095	1,787	13,006	5,828
Net interest income after provision for loan losses	96,943	65,068	230,832	184,774
Noninterest income
Service charges on deposit accounts	12,690	10,535	33,531	31,714
Mortgage banking activity	13,413	13,340	40,203	38,498
Other service charges, commissions and fees	777	699	2,193	2,137
Gain (loss) on securities	48	0	(38)	37
Other noninterest income	3,243	2,425	12,053	8,508
Total noninterest income	30,171	26,999	87,942	80,894
Noninterest expense
Salaries and employee benefits	38,446	32,583	110,311	89,509
Occupancy and equipment expense	8,598	6,036	21,186	18,059
Data processing and communications costs	8,518	7,050	22,092	20,650
Credit resolution-related expenses	1,248	1,347	2,842	2,879
Advertising and marketing expense	1,453	1,247	3,938	3,612
Amortization of intangible assets	2,676	941	5,862	2,990
Merger and conversion charges	276	92	19,502	494
Other noninterest expenses	11,138	14,471	32,104	34,406
Total noninterest expense	72,353	63,767	217,837	172,599
Income before income tax expense	54,761	28,300	100,937	93,069
Income tax expense	13,317	8,142	23,446	28,671
Net income	41,444	20,158	77,491	64,398
Other comprehensive income
Net unrealized holding gains (losses) arising during period on investment securities available for sale, net of tax expense (benefit) of ($1,053), $966, ($4,035) and $2,348	(3,964)	1,795	(15,181)	4,361
Reclassification adjustment for gains on investment securities included in earnings, net of tax of $11, $0, $19 and $13	(41)	0	(70)	(24)
Unrealized gains (losses) on cash flow hedges arising during period, net of tax expense (benefit) of $0, $14, $92 and ($21)	0	25	347	(38)
Other comprehensive income (loss)	(4,005)	1,820	(14,904)	4,299
Total comprehensive income	$ 37,439	$ 21,978	$ 62,587	$ 68,697
Basic earnings per common share (in dollars per share)	$ 0.87	$ 0.54	$ 1.86	$ 1.76
Diluted earnings per common share (in dollars per share)	0.87	0.54	1.85	1.74
Dividends declared per common share (in dollars per share)	$ 0.10	$ 0.10	$ 0.30	$ 0.30
Weighted average common shares outstanding (in thousands)
Basic (in shares)	47,515	37,225	41,673	36,690
Diluted (in shares)	47,685	37,553	41,845	37,017