Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Operating Activities
Net income	$ 33,510	$ 22,855
Adjustments to reconcile net income to net cash provided by operating activities:
Provision for loan losses	15,181	4,918
Depreciation of premises, furniture, and equipment	3,606	3,461
Net amortization of premium on securities	3,848	4,284
Gains on sales of 1-4 family mortgages and corporate loans held-for-sale	(1,625)	(1,414)
Net losses on sales and valuation adjustments of OREO	440	689
Amortization of the FDIC indemnification asset	302	302
Net losses on sales and valuation adjustments of premises, furniture, and equipment	60	113
BOLI income	(1,373)	(1,260)
Share-based compensation expense	3,367	2,965
Tax benefit related to share-based compensation	51	29
Amortization of other intangible assets	1,802	1,541
Originations of mortgage loans held-for-sale	(49,535)	(43,132)
Proceeds from sales of mortgage loans held-for-sale	65,185	55,761
Net increase in equity securities	(658)	0
Net increase in trading securities	0	(1,210)
Net increase in accrued interest receivable and other assets	(7,309)	(6,767)
Net decrease in accrued interest payables and other liabilities	(31,120)	(34,934)
Net cash provided by operating activities	35,732	8,201
Investing Activities
Proceeds from maturities, repayments, and calls of securities available-for-sale	70,236	80,060
Proceeds from sales of securities available-for-sale	0	210,154
Purchases of securities available-for-sale	(263,386)	(94,766)
Proceeds from maturities, repayments, and calls of securities held-to-maturity	360	4,549
Net purchases of FHLB stock	(10,800)	16,072
Net increase in loans	(255,057)	(43,771)
Premiums paid on BOLI, net of proceeds from claims	(12)	(24)
Proceeds from sales of OREO	3,876	5,364
Proceeds from sales of premises, furniture, and equipment	146	404
Purchases of premises, furniture, and equipment	(6,844)	(2,891)
Net cash received from acquisitions	0	41,717
Net cash (used in) provided by investing activities	(461,481)	216,868
Financing Activities
Net increase in deposit accounts	92,697	104,064
Net increase (decrease) in borrowed funds	235,804	(331,085)
Cash dividends paid	(10,288)	(7,206)
Restricted stock activity	(3,998)	(3,830)
Net cash provided by (used in) financing activities	314,215	(238,057)
Net decrease in cash and cash equivalents	(111,534)	(12,988)
Cash and cash equivalents at beginning of period	346,570	262,148
Cash and cash equivalents at end of period	235,036	249,160
Supplemental Disclosures of Cash Flow Information:
Income taxes paid	116	(1,259)
Interest paid to depositors and creditors	13,379	9,354
Dividends declared, but unpaid	11,246	9,163
Stock issued for acquisitions, net of issuance costs	0	534,090
Non-cash transfers of loans to OREO	937	683
Non-cash transfers of loans held-for-investment to loans held-for-sale	905	13,136
Non-cash transfer of equity securities previously classified as trading securities and securities available-for-sale	$ 27,855	$ 0