Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Cash and cash equivalents:
Cash and due from banks	$ 255,775	$ 201,966
Interest-bearing deposits with banks	117,635	36,241
Federal funds sold and securities purchased under agreements to resell	4,217	136,241
Total cash and cash equivalents	377,627	374,448
Investment securities:
Securities held to maturity (fair value of $2,556 and $6,250, respectively)	2,529	6,094
Securities available for sale, at fair value	1,650,710	999,405
Other investments	20,530	9,482
Total investment securities	1,673,769	1,014,981
Loans held for sale	70,890	50,572
Loans:
Total loans	1,289
Loans, net	10,575,417	6,643,326
Other real estate owned	11,203	18,316
Premises and equipment, net	255,565	183,510
Bank owned life insurance	225,132	104,148
Deferred tax assets	45,902	31,123
Mortgage servicing rights	31,119	29,037
Core deposit and other intangibles	73,789	39,848
Goodwill	999,586	338,340
Other assets	126,590	72,943
Total assets	14,466,589	8,900,592
Deposits:
Noninterest-bearing	3,047,432	2,199,046
Interest-bearing	8,485,334	5,135,377
Total deposits	11,532,766	7,334,423
Federal funds purchased and securities sold under agreements to repurchase	286,857	313,773
Other borrowings	216,385	55,358
Other liabilities	121,661	62,450
Total liabilities	12,157,669	7,766,004
Shareholders' equity:
Preferred stock - $.01 par value; authorized 10,000,000 shares; no shares issued and outstanding
Common stock - $2.50 par value; authorized 80,000,000 and 40,000,000 shares, respectively; 36,759,656 and 24,230,392 shares issued and outstanding, respectively	91,899	60,576
Surplus	1,807,601	711,307
Retained earnings	419,847	370,916
Accumulated other comprehensive income (loss)	(10,427)	(8,211)
Total shareholders' equity	2,308,920	1,134,588
Total liabilities and shareholders' equity	14,466,589	8,900,592
Acquired credit impaired loans
Loans:
Loans, net	618,803	602,546
Non-acquired loans
Loans:
Loans, net	6,492,155	5,241,041
Total loans	6,492,155	5,241,041
Less allowance for non-acquired loan losses	(43,448)	(36,960)
Loans, net	6,448,707	5,204,081
Acquired non-credit impaired loans
Loans:
Loans, net	3,507,907	836,699
Total loans	$ 3,507,907	$ 836,699