CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income	$ 41,380	$ 31,517
Adjustments to reconcile net income to net cash provided (used) by operating activities:
Amortization and accretion of premiums and discounts on securities, net	2,286	1,126
Accretion of loan discounts, net	(3,363)	(3,752)
Amortization of deposit premiums	(578)	(781)
Amortization of core deposit intangibles	919	1,140
Amortization and accretion of borrowing and debt valuation allowance, net	315	315
Amortization of issuance costs of subordinated notes	109	109
Provision for loan losses	11,880	9,955
Depreciation	1,378	1,558
Net gain on sale of available-for-sale securities	(66)	38
Net loss on sale of real estate acquired by foreclosure	0	147
Net gain on loans held-for-sale	0	1,210
Net gain on sale of guaranteed portion of loans	(2,758)	(4,107)
Net market value loss on equity investments	345	0
Originations of government guaranteed loans held-for-sale	(31,083)	0
Proceeds from sales of and principal collected on loans held-for-sale	33,370	15,136
Writedown of real estate acquired by foreclosure	0	304
Stock-based compensation expense	2,853	1,700
Deferred tax benefit	(3,942)	(2,062)
Net change in accrued interest receivable and other assets, net	(3,606)	17,340
Net change in accrued interest payable and other liabilities, net	3,317	2,281
Net cash provided by operating activities	52,756	73,174
CASH FLOWS FROM INVESTING ACTIVITIES:
Proceeds from the maturities or calls and paydowns of available-for-sale securities	65,197	55,811
Proceeds from the sale of available-for-sale securities	24,424	349,374
Purchases of available-for-sale securities	(74,191)	(811,919)
Proceeds from the maturities or calls and paydowns of held-to-maturity securities	4,392	5,833
Purchases of held-to-maturity securities	(3,627)	0
Proceeds from sales of guaranteed portion of loans	0	45,957
Proceeds from sales of real estate acquired by foreclosure	0	3,967
Purchases of Federal Home Loan Bank of Dallas stock, net of redemptions	(6,656)	(3,399)
Purchases of Federal Reserve Bank stock	(143)	(395)
Net increase in loans held for investment	(185,113)	(29,778)
Investment in construction of premises and purchases of other fixed assets	(286)	(347)
Net cash used in investing activities	(176,003)	(384,896)
CASH FLOWS FROM FINANCING ACTIVITIES:
Net increase (decrease) in deposit accounts	17,907	34,334
Net (decrease) increase in securities sold under agreements to repurchase	(1,671)	2,374
Net proceeds from other short-term borrowed funds	112,000	65,000
Proceeds from other long-term borrowed funds	50,000	0
Repayment of other long-term borrowed funds	50,000	0
Proceeds from issuance of common stock due to exercise of stock options	2,884	470
Payments of cash dividends	(7,464)	0
Net cash provided by financing activities	123,656	102,178
NET INCREASE (DECREASE) IN CASH AND CASH EQUIVALENTS	409	(209,544)
CASH AND CASH EQUIVALENTS:
Beginning of period	140,681	389,007
End of period	141,090	179,463
NONCASH ACTIVITIES:
Noncash investing and financing activities - acquisition of real estate through foreclosure of collateral	7,693	5,270
Transfer of loans to held-for-sale	0	10,030
Transfer of securities to available-for-sale	0	15,883
SUPPLEMENTAL INFORMATION:
Interest paid	29,442	29,498
Income taxes paid	$ 12,000	$ 11,700