Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017	Sep. 30, 2017
Cash and cash equivalents:
Cash and due from banks	$ 234,011	$ 255,775	$ 197,984
Interest-bearing deposits with banks	25,950	117,635	137,543
Federal funds sold and securities purchased under agreements to resell	47,348	4,217	68,407
Total cash and cash equivalents	307,309	377,627	403,934
Investment securities:
Securities held to maturity (fair value of $500, $2,556 and $3,732, respectively)	500	2,529	3,678
Securities available for sale, at fair value	1,551,281	1,648,193	1,319,454
Other investments	19,229	23,047	13,664
Total investment securities	1,571,010	1,673,769	1,336,796
Loans held for sale	33,752	70,890	46,321
Loans:
Loans, net	10,855,344	10,575,417	8,223,204
Other real estate owned	12,119	11,203	13,527
Premises and equipment, net	241,909	255,565	198,146
Bank owned life insurance	229,075	225,132	151,402
Deferred tax assets	47,943	45,902	41,664
Mortgage servicing rights	36,056	31,119	29,937
Core deposit and other intangibles	66,437	73,789	50,472
Goodwill	1,002,900	999,586	597,236
Other assets	118,361	126,590	76,471
Total assets	14,522,215	14,466,589	11,169,110
Deposits:
Noninterest-bearing	3,157,478	3,047,432	2,505,570
Interest-bearing	8,456,397	8,485,334	6,556,451
Total deposits	11,613,875	11,532,766	9,062,021
Federal funds purchased and securities sold under agreements to repurchase	279,698	286,857	291,099
Other borrowings	115,919	216,385	83,307
Other liabilities	144,584	121,661	99,858
Total liabilities	12,154,076	12,157,669	9,536,285
Shareholders' equity:
Common stock - $2.50 par value; authorized 80,000,000; 80,000,000 and 40,000,000 shares, respectively; 36,723,238; 36,759,656 and 29,267,369 shares issued and outstanding, respectively	91,808	91,899	73,168
Surplus	1,805,685	1,807,601	1,136,352
Retained earnings	515,155	419,847	427,093
Accumulated other comprehensive loss	(44,509)	(10,427)	(3,788)
Total shareholders' equity	2,368,139	2,308,920	1,632,825
Total liabilities and shareholders' equity	14,522,215	14,466,589	11,169,110
Acquired credit impaired loans
Loans:
Loans, net	512,633	618,803	578,863
Total loans	516,601	623,430	582,533
Acquired non-credit impaired loans
Loans:
Total loans	2,786,102	3,507,907	1,455,555
Non-acquired loans
Loans:
Total loans	7,606,478	6,492,155	6,230,327
Less allowance for non-acquired loan losses	(49,869)	(43,448)	(41,541)
Loans, net	$ 7,556,609	$ 6,448,707	$ 6,188,786