CONSOLIDATED STATEMENTS OF INCOME (Unaudited) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Interest income:
Loans, including fees	$ 221,901,000	$ 183,570,000	$ 621,873,000	$ 389,093,000
Securities:
Taxable	12,209,000	12,067,000	35,179,000	26,765,000
Tax-exempt	10,074,000	4,620,000	25,709,000	8,533,000
Federal funds sold and other	3,926,000	1,639,000	7,861,000	3,376,000
Total interest income	248,110,000	201,896,000	690,622,000	427,767,000
Interest expense:
Deposits	44,172,000	19,104,000	100,920,000	38,216,000
Securities sold under agreements to repurchase	165,000	148,000	438,000	277,000
Federal Home Loan Bank advances and other borrowings	14,353,000	9,734,000	43,137,000	20,984,000
Total interest expense	58,690,000	28,986,000	144,495,000	59,477,000
Net interest income	189,420,000	172,910,000	546,127,000	368,290,000
Provision for loan losses	8,725,000	6,920,000	25,058,000	17,384,000
Net interest income after provision for loan losses	180,695,000	165,990,000	521,069,000	350,906,000
Noninterest income:
Total noninterest income	51,478,000	43,248,000	143,600,000	108,701,000
Noninterest expense:
Salaries and employee benefits	69,117,000	64,288,000	196,948,000	146,316,000
Equipment and occupancy	19,252,000	16,590,000	55,203,000	36,978,000
Other real estate expense	67,000	513,000	92,000	827,000
Marketing and other business development	3,293,000	2,222,000	8,084,000	6,228,000
Postage and supplies	1,654,000	1,755,000	5,984,000	4,074,000
Amortization of intangibles	2,616,000	3,077,000	7,973,000	5,745,000
Merger related expense	0	8,847,000	8,259,000	12,740,000
Other noninterest expense	17,991,000	12,444,000	50,935,000	30,679,000
Total noninterest expense	113,990,000	109,736,000	333,478,000	243,587,000
Income before income taxes	118,183,000	99,502,000	331,191,000	216,020,000
Income tax expense	24,436,000	35,060,000	67,069,000	68,839,000
Net income	$ 93,747,000	$ 64,442,000	$ 264,122,000	$ 147,181,000
Per share information:
Basic net income per common share (in dollars per share)	$ 1.22	$ 0.84	$ 3.42	$ 2.48
Diluted net income per common share (in dollars per share)	$ 1.21	$ 0.83	$ 3.41	$ 2.46
Weighted average shares outstanding:
Basic (in shares)	77,145,023	76,678,584	77,116,377	59,371,202
Diluted (in shares)	77,490,977	77,232,098	77,442,554	59,910,344
Service charges on deposit accounts
Noninterest income:
Total noninterest income	$ 6,404,000	$ 5,921,000	$ 18,289,000	$ 13,955,000
Investment services
Noninterest income:
Total noninterest income	5,237,000	3,660,000	15,250,000	9,592,000
Insurance sales commissions
Noninterest income:
Total noninterest income	2,126,000	2,123,000	7,293,000	5,444,000
Gain on mortgage loans sold, net
Noninterest income:
Total noninterest income	3,902,000	5,963,000	11,423,000	14,785,000
Gain on sale of investment securities, net
Noninterest income:
Total noninterest income	11,000	0	41,000	0
Trust fees
Noninterest income:
Total noninterest income	3,087,000	2,636,000	9,768,000	6,019,000
Income from equity method investment
Noninterest income:
Total noninterest income	14,236,000	8,937,000	33,286,000	25,514,000
Other noninterest income
Noninterest income:
Total noninterest income	$ 16,475,000	$ 14,008,000	$ 48,250,000	$ 33,392,000