Consolidated Balance Sheets (Unaudited) - USD ($) $ in Thousands	Mar. 31, 2016	Dec. 31, 2015
Assets
Cash and due from banks	$ 113,755	$ 132,595
Federal funds sold	196	563
Interest bearing deposits in banks	541,577	647,299
Total cash and cash equivalents	655,528	780,457
Investment securities:
Available-for-sale	1,563,350	1,456,840
Held-to-maturity (estimated fair values of $593,904 and $607,550 at March 31, 2016 and December 31, 2015, respectively)	581,390	600,665
Total investment securities	2,144,740	2,057,505
Loans held for investment	5,191,469	5,193,321
Mortgage loans held for sale	52,989	52,875
Total loans	5,244,458	5,246,196
Less allowance for loan losses	79,924	76,817
Net loans	5,164,534	5,169,379
Goodwill	204,481	204,523
Premises and equipment, net of accumulated depreciation	188,714	190,812
Company-owned life insurance	188,396	187,253
Other real estate owned (OREO)	9,257	6,254
Accrued interest receivable	26,907	27,729
Core deposit intangibles, net of accumulated amortization	9,762	10,589
Mortgage servicing rights, net of accumulated amortization and impairment reserve	15,574	15,621
Other assets	82,787	78,074
Total assets	8,690,680	8,728,196
Deposits:
Non-interest bearing	1,860,472	1,823,716
Interest bearing	5,246,991	5,265,221
Total deposits	7,107,463	7,088,937
Securities sold under repurchase agreements	465,523	510,635
Accounts payable and accrued expenses	48,102	53,042
Accrued interest payable	5,184	4,960
Deferred tax liability	11,977	9,765
Long-term debt	27,907	27,885
Other borrowed funds	33	2
Subordinated debentures held by subsidiary trusts	82,477	82,477
Total liabilities	7,748,666	7,777,703
Stockholders' equity:
Nonvoting noncumulative preferred stock without par value; authorized 100,000 shares; no shares issued and outstanding as of March 31, 2016 or December 31, 2015	0	0
Common stock	288,782	311,720
Retained earnings	648,631	638,367
Accumulated other comprehensive income, net	4,601	406
Total stockholders' equity	942,014	950,493
Total liabilities and stockholders' equity	$ 8,690,680	$ 8,728,196