Consolidated Statements of Cash Flows - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Cash Flows From Operating Activities
Net income	$ 29,199	$ 21,259
Adjustments to reconcile net income to net cash provided by operating activities
Provision for loan and lease losses	2,775	5,254
Stock-based compensation expense	2,358	1,180
Depreciation, amortization and accretion	6,074	10,798
Investment securities gains	0	373
Net realized loss on sale of premises and equipment, loans held for investment and other assets	55	106
Net realized loss on sale and valuation adjustments of other real estate owned	(204)	(90)
Originations of loans held for sale	31,295	19,174
Proceeds from sales of loans held for sale	33,896	20,002
Net change in:
Interest receivable	(1,271)	(1,427)
Interest payable	(9)	(55)
Other assets	(2,164)	(3,731)
Other liabilities	(3,841)	(4,619)
Net cash provided by operating activities	35,981	29,310
Cash Flows From Investing Activities
Loans originated and acquired, net of principal collected	(21,936)	(64,056)
Purchases of securities available for sale	(108,958)	(95,686)
Purchases of premises and equipment	(336)	(445)
Payments to Acquire Federal Home Loan Bank Stock	(31,400)	(10,520)
Proceeds from FDIC for reimbursement on loss-sharing asset	26	258
Proceeds from sales of securities available for sale	0	38,876
Proceeds from principal repayments and maturities of securities available for sale	55,369	52,422
Proceeds from Sales of Assets, Investing Activities	6,893	1,911
Proceeds from Sale of Federal Home Loan Bank Stock	31,040	13,001
Proceeds from sales of other real estate and other personal property owned	1,275	1,326
Payments to FDIC related to loss-sharing asset	(210)	(611)
Net cash used in investing activities	(68,237)	(63,524)
Cash Flows From Financing Activities
Net increase in deposits	29,433	158,120
Net decrease in sweep repurchase agreements	(33,908)	(25,860)
Proceeds from Federal Home Loan Bank advances	785,000	165,000
Proceeds from exercise of stock options	1,145	598
Repayment of Federal Home Loan Bank advances	(776,000)	(227,000)
Payment of common stock dividends	(12,792)	(21,943)
Preferred stock dividends	0	(39)
Purchase and retirement of common stock	2,039	1,033
Net cash (used in) provided by financing activities	(9,161)	47,843
Increase (decrease) in cash and cash equivalents	(41,417)	13,629
Cash and cash equivalents at beginning of period	224,238	175,302
Cash and cash equivalents at end of period	182,821	188,931
Supplemental Information:
Cash paid for interest	1,150	1,059
Cash paid for income tax	0	6,350
Non-cash investing and financing activities
Loans transferred to other real estate owned	$ 0	$ 105