Consolidated Statement of Cash Flows - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income (loss)	$ 31,517	$ (3,516)
Adjustments to reconcile net income to net cash provided (used) by operating activities:
Amortization and accretion of premiums and discounts on securities, net	1,126	610
Accretion of loan discounts, net	(3,752)	(6,768)
Amortization of deposit premiums	(781)	(1,947)
Amortization of core deposit intangibles	1,140	1,206
Amortization and accretion of borrowing and debt valuation allowance, net	315	184
Amortization of issuance costs for subordinated notes	109
Provision for loan losses	9,955	55,200
Depreciation	1,558	1,832
Net loss on sale of available-for-sale securities	38
Net loss on sale of real estate acquired by foreclosure	147	566
Net loss (gain) on loans held-for-sale	1,210	(41)
Net gain on sale of guaranteed portion of loans	(4,107)	(2,964)
Originations of loans held for sale		(1,094)
Proceeds from sales of and principal collected on loans held for sale	15,136	7,772
Writedown of real estate acquired by foreclosure	304	1,048
Stock-based compensation expense	1,700	951
Deferred tax benefit	(2,062)	(878)
Decrease (increase) in accrued interest receivable and other assets, net	17,340	(16,434)
Increase in accrued interest payable and other liabilities, net	2,281	4,880
Net cash provided by operating activities	73,174	40,607
CASH FLOWS FROM INVESTING ACTIVITIES:
Proceeds from the maturities or calls and paydowns of available-for-sale securities	55,811	96,108
Proceeds from the sale of available-for-sale securities	349,374
Purchases of available-for-sale securities	(811,919)	(100,335)
Proceeds from the maturities or calls and paydowns of held-to-maturity securities	5,833	6,306
Purchases of held-to-maturity securities		(1,963)
Proceeds from sale of guaranteed portion of loans	45,957	35,482
Proceeds from sale of real estate acquired by foreclosure	3,967	8,127
Purchases of Federal Home Loan Bank of Dallas stock, net of redemptions	(3,399)	6,103
Purchases of Federal Reserve Bank stock	(395)	(3,738)
Net increase in loans held for investment	(29,778)	(40,542)
Investment in construction of premises and purchases of other fixed assets	(347)	(260)
Net cash provided by (used in) investing activities	(384,896)	5,288
CASH FLOWS FROM FINANCING ACTIVITIES:
Net increase in deposit accounts	34,334	217,098
Net decrease (increase) in securities sold under agreements to repurchase	2,374	(218)
Net proceeds (repayments) of other short-term borrowed funds	65,000	(64,250)
Proceeds from other long-term borrowed funds		50,000
Repayment of other long-term borrowed funds		(58,884)
Proceeds from issuance of common stock due to exercise of stock options	470	72
Purchase of treasury stock		(1,253)
Net cash provided by financing activities	102,178	142,565
NET (DECREASE) INCREASE IN CASH AND CASH EQUIVALENTS	(209,544)	188,460
CASH AND CASH EQUIVALENTS:
Beginning of year	389,007	124,906
End of year	179,463	313,366
NONCASH ACTIVITIES:
Noncash investing and financing activities - acquisition of real estate through foreclosure of collateral	5,270	420
Transfer of loans to held-for-sale	10,030	45,187
Transfer of securities to available-for-sale	15,883
SUPPLEMENTAL INFORMATION:
Interest paid	29,498	17,379
Income taxes paid	$ 11,700	$ 11,700