Consolidated Statements of Income and Comprehensive Income (Unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Interest income
Interest and fees on loans	$ 117,010	$ 82,723	$ 229,411	$ 155,990
Interest on taxable securities	9,383	6,321	18,426	11,528
Interest on nontaxable securities	102	179	258	501
Interest on deposits in other banks and federal funds sold	2,533	723	5,862	1,439
Total interest income	129,028	89,946	253,957	169,458
Interest expense
Interest on deposits	23,454	7,794	45,138	14,566
Interest on other borrowings	3,923	6,153	7,773	10,092
Total interest expense	27,377	13,947	52,911	24,658
Net interest income	101,651	75,999	201,046	144,800
Provision for loan losses	4,668	9,110	8,076	10,911
Net interest income after provision for loan losses	96,983	66,889	192,970	133,889
Noninterest income
Service charges on deposit accounts	12,168	10,613	23,814	20,841
Mortgage banking activity	18,523	15,403	33,200	27,689
Other service charges, commissions and fees	793	697	1,561	1,416
Net gain (loss) on securities	69	(123)	135	(86)
Other noninterest income	3,683	4,717	7,297	7,911
Total noninterest income	35,236	31,307	66,007	57,771
Noninterest expense
Salaries and employee benefits	38,441	39,776	76,811	71,865
Occupancy and equipment expense	7,834	6,390	16,038	12,588
Data processing and communications expenses	8,388	6,439	16,779	13,574
Credit resolution-related expenses	979	1,045	1,890	1,594
Advertising and marketing expense	1,987	1,256	3,728	2,485
Amortization of intangible assets	3,121	2,252	6,253	3,186
Merger and conversion charges	3,475	18,391	5,532	19,226
Other noninterest expenses	17,026	10,837	29,645	20,966
Total noninterest expense	81,251	86,386	156,676	145,484
Income before income tax expense	50,968	11,810	102,301	46,176
Income tax expense	12,064	2,423	23,492	10,129
Net income	38,904	9,387	78,809	36,047
Other comprehensive income (loss)
Net unrealized holding gains (losses) arising during period on investment securities available for sale, net of tax expense (benefit) of $4,765, ($482), $5,793 and ($2,982)	17,927	(1,814)	21,794	(11,217)
Reclassification adjustment for gains on investment securities included in earnings, net of tax of $13, $0, $25 and $8	(48)	0	(94)	(29)
Unrealized gains (losses) on cash flow hedges arising during period, net of tax expense (benefit) of ($64), $17, ($110) and $92	(239)	66	(412)	347
Other comprehensive income (loss)	17,640	(1,748)	21,288	(10,899)
Total comprehensive income	$ 56,544	$ 7,639	$ 100,097	$ 25,148
Basic earnings per common share (in dollars per share)	$ 0.82	$ 0.24	$ 1.66	$ 0.93
Diluted earnings per common share (in dollars per share)	$ 0.82	$ 0.24	$ 1.66	$ 0.92
Weighted average common shares outstanding (in thousands)
Basic (in shares)	47,311	39,432	47,354	38,703
Diluted (in shares)	47,338	39,710	47,395	38,981