Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Cash and cash equivalents:
Cash and due from banks	$ 262,019	$ 251,411
Interest-bearing deposits with banks	426,685	124,895
Federal funds sold and securities purchased under agreements to resell		32,677
Total cash and cash equivalents	688,704	408,983
Investment securities:
Securities available for sale, at fair value	1,956,047	1,517,067
Other investments	49,124	25,604
Total investment securities	2,005,171	1,542,671
Loans held for sale	59,363	22,925
Loans:
Loans, net	11,313,113	10,962,037
Other real estate owned	11,964	11,410
Premises and equipment, net	317,321	241,076
Bank owned life insurance	234,567	230,105
Deferred tax assets	31,316	37,128
Mortgage servicing rights	30,525	34,727
Core deposit and other intangibles	49,816	62,900
Goodwill	1,002,900	1,002,900
Other assets	176,332	119,466
Total assets	15,921,092	14,676,328
Deposits:
Noninterest-bearing	3,245,306	3,061,769
Interest-bearing	8,931,790	8,585,164
Total deposits	12,177,096	11,646,933
Federal funds purchased and securities sold under agreements to repurchase	298,741	270,649
Other borrowings	815,936	266,084
Other liabilities	256,306	126,366
Total liabilities	13,548,079	12,310,032
Shareholders' equity:
Common stock - $2.50 par value; authorized 80,000,000 shares; 33,744,385 and 35,829,549 shares issued and outstanding, respectively	84,361	89,574
Surplus	1,607,740	1,750,495
Retained earnings	679,895	551,108
Accumulated other comprehensive income (loss)	1,017	(24,881)
Total shareholders' equity	2,373,013	2,366,296
Total liabilities and shareholders' equity	15,921,092	14,676,328
Acquired credit impaired loans
Loans:
Lones, net	356,782	485,119
Acquired non-credit impaired loans
Loans:
Total loans	1,760,427	2,594,826
Non-acquired loans
Loans:
Total loans	9,252,831	7,933,286
Less allowance for non-acquired loan losses	(56,927)	(51,194)
Loans, net	$ 9,195,904	$ 7,882,092