Consolidated Balance Sheets (Unaudited) - USD ($) $ in Thousands	Mar. 31, 2017	Dec. 31, 2016
Assets
Cash and due from banks	$ 137,777	$ 146,779
Federal funds sold	95	95
Interest bearing deposits in banks	670,080	635,149
Total cash and cash equivalents	807,952	782,023
Investment securities:
Available-for-sale	1,657,591	1,611,698
Held-to-maturity (estimated fair values of $493,925 and $513,273 at March 31, 2017 and December 31, 2016, respectively)	490,968	512,770
Total investment securities	2,148,559	2,124,468
Loans held for investment	5,376,542	5,416,750
Mortgage loans held for sale	23,237	61,794
Total loans	5,399,779	5,478,544
Less allowance for loan losses	76,231	76,214
Net loans	5,323,548	5,402,330
Goodwill	212,820	212,820
Premises and equipment, net of accumulated depreciation	195,472	194,457
Company-owned life insurance	199,262	198,116
Other real estate owned (OREO)	9,428	10,019
Accrued interest receivable	27,712	29,852
Core deposit intangibles, net of accumulated amortization	9,018	9,648
Mortgage servicing rights, net of accumulated amortization and impairment reserve	19,454	18,457
Other assets	108,009	81,705
Total assets	9,061,234	9,063,895
Deposits:
Non-interest bearing	1,840,647	1,906,257
Interest bearing	5,459,532	5,469,853
Total deposits	7,300,179	7,376,110
Securities sold under repurchase agreements	587,570	537,556
Accounts payable and accrued expenses	43,838	44,923
Accrued interest payable	4,831	5,421
Deferred tax liability	12,748	6,839
Long-term debt	27,994	27,970
Other borrowed funds	1	6
Subordinated debentures held by subsidiary trusts	82,477	82,477
Total liabilities	8,059,638	8,081,302
Stockholders' equity:
Nonvoting noncumulative preferred stock without par value; authorized 100,000 shares; no shares issued and outstanding as of March 31, 2017 or December 31, 2016	0	0
Common stock	297,173	296,071
Retained earnings	707,016	694,650
Accumulated other comprehensive income, net	(2,593)	(8,128)
Total stockholders' equity	1,001,596	982,593
Total liabilities and stockholders' equity	$ 9,061,234	$ 9,063,895