Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Cash Flows From Operating Activities
Net income	$ 104,866	$ 98,827	$ 81,574
Adjustments to reconcile net income to net cash provided by operating activities:
Provision for loan and lease losses	10,778	8,591	6,727
Stock-based compensation expense	5,009	4,090	2,859
Depreciation, amortization and accretion	34,542	30,312	44,459
Investment securities gain, net	(1,181)	(1,581)	(552)
Net realized loss on sale of premises and equipment, loans held for investment and other assets	157	573	564
Net gain on sale and valuation adjustments of OREO	(629)	2,152	1,870
Net realized gain on sale of branches	0	0	(565)
Originations of loans held for sale	(110,467)	(75,689)	(23,344)
Proceeds from Sale of Loans Held-for-sale	109,130	72,296	23,573
Deferred income tax expense (benefit)	1,846	6,367	14,646
Net change in:
Interest receivable	(2,197)	(75)	(944)
Interest payable	(93)	(142)	89
Other assets	(15,917)	(5,419)	(4,479)
Other liabilities	8,745	(1,242)	(5,119)
Net cash provided by operating activities	145,847	134,756	137,618
Cash Flows From Investing Activities
Payments for (Proceeds from) Loans and Leases	(402,146)	(384,321)	(440,376)
Purchases of securities available for sale	(569,825)	(467,631)	(363,693)
Purchases of premises and equipment	(4,520)	(7,581)	(12,485)
Payments to Acquire Federal Home Loan Bank Stock	(59,599)	(16,760)	0
Proceeds from FDIC for reimbursement on loss-sharing asset	927	4,659	5,950
Proceeds from sales of securities available for sale	124,142	95,375	63,292
Proceeds from principal repayments and maturities of securities available for sale	284,218	283,206	180,648
Proceeds from sales of loans held for investment and other assets	9,643	15,074	2,840
Proceeds from Sale of Federal Home Loan Bank Stock	62,081	37,403	1,288
Proceeds from sales of other real estate and other personal property owned	8,158	19,387	28,559
Payment to FDIC Related to Loss-Sharing Asset	(1,632)	(1,865)	(3,451)
Net cash paid in branch sale	0	0	(16,788)
Net cash received in business combinations	0	0	32,255
Net cash used in investing activities	(548,553)	(423,054)	(521,961)
Cash Flows From Financing Activities
Net increase (decrease) in deposits	620,785	514,107	250,629
Net decrease in repurchase agreements	(18,877)	(5,381)	21,037
Proceeds from exercise of stock options	1,349	1,258	929
Proceeds from Warrant Exercises	0	0	5,000
Proceeds from Federal Home Loan Bank advances	1,392,000	1,702,000	1,602,000
Proceeds from Federal Reserve Bank borrowings	10	1,010	800
Repayment of Federal Home Loan Bank advances	(1,454,000)	(1,850,000)	(1,422,000)
Repayment of Federal Reserve Bank borrowings	(10)	(1,010)	(800)
Payment of preferred stock dividends	(157)	(137)	(96)
Payment of common stock dividends	(88,677)	(77,263)	(49,494)
Repayment of other borrowings	0	(8,248)	(14,636)
Purchase and retirement of common stock	(1,125)	(906)	(622)
Proceeds from excess tax benefit from stock-based compensation	(344)	0	(205)
Net cash provided by financing activities	451,642	275,430	392,952
Increase (decrease) in cash and cash equivalents	48,936	(12,868)	8,609
Cash and cash equivalents at beginning of period	175,302	188,170	179,561
Supplemental Information:
Cash paid for interest	4,444	4,146	3,904
Cash paid for income tax	32,723	30,522	21,230
Non-cash investing and financing activities
Loans transferred to other real estate owned	1,047	8,688	10,200
Share-based consideration issued in business combinations	$ 0	$ 0	$ 116,907