Consolidated Statements of Cash Flows - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017
Operating Activities
Net income	$ 116,462	$ 96,040
Adjustments to reconcile net income to net cash provided by operating activities:
Provision for loan losses	38,043	23,266
Depreciation of premises, furniture, and equipment	11,693	10,477
Net amortization of premium on securities	11,444	12,334
Net securities gains	0
Net securities gains		(3,481)
Gains on sales of 1-4 family mortgages and corporate loans held-for-sale	(4,475)	(5,354)
Net (gains) losses on sales and valuation adjustments of OREO	(318)	944
Amortization of the FDIC indemnification asset	906	906
Net losses (gains) on sales and valuation adjustments of premises, furniture, and equipment	5,423	(364)
BOLI income	(4,280)	(4,095)
Share-based compensation expense	9,164	8,554
Tax benefit related to share-based compensation	208	252
Amortization of other intangible assets	5,368	6,059
Originations of mortgage loans held-for-sale	(175,408)	(183,907)
Proceeds from sales of mortgage loans held-for-sale	193,476	190,544
Net increase in equity securities	(1,191)	0
Net increase in trading securities	0	(2,505)
Net increase in accrued interest receivable and other assets	(14,725)	(191,492)
Net decrease in accrued interest payables and other liabilities	(1,949)	(8,463)
Net cash provided by (used in) operating activities	189,841	(50,285)
Investing Activities
Proceeds from maturities, repayments, and calls of securities available-for-sale	233,659	251,160
Proceeds from sales of securities available-for-sale	0	437,401
Purchases of securities available-for-sale	(595,477)	(289,244)
Proceeds from maturities, repayments, and calls of securities held-to-maturity	1,087	7,663
Purchases of securities held-to-maturity	0	(10)
Net purchases of FHLB stock	(18,020)	(7,330)
Net increase in loans	(649,197)	(392,384)
Premiums paid on BOLI, net of proceeds from claims	106	132
Proceeds from sales of OREO	12,951	17,460
Proceeds from sales of premises, furniture, and equipment	549	13,135
Purchases of premises, furniture, and equipment	(20,738)	(11,680)
Net cash received from acquisitions	0	41,717
Net cash (used in) provided by investing activities	(1,035,080)	68,020
Financing Activities
Net increase in deposit accounts	473,789	356,020
Net increase (decrease) in borrowed funds	358,662	(178,472)
Cash dividends paid	(32,942)	(26,852)
Restricted stock activity	(4,241)	(3,679)
Net cash provided by financing activities	795,268	147,017
Net (decrease) increase in cash and cash equivalents	(49,971)	164,752
Cash and cash equivalents at beginning of period	346,570	262,148
Cash and cash equivalents at end of period	296,599	426,900
Supplemental Disclosures of Cash Flow Information:
Income taxes (refunded) paid	(7,001)	14,310
Interest paid to depositors and creditors	43,270	27,538
Dividends declared, but unpaid	11,250	10,184
Stock issued for acquisitions, net of issuance costs	0	534,090
Non-cash transfers of loans to OREO	4,026	3,770
Non-cash transfers of loans held-for-investment to loans held-for-sale	12,373	42,970
Non-cash transfer of trading securities and securities available-for-sale to equity securities	$ 27,855	$ 0