Consolidated Statements Of Cash Flows (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Operating Activities:
Net income	$ 49,111	$ 39,052
Adjustments to reconcile net income to net cash provided by (used for) operating activities
Provision for credit losses	8,034	6,079
Depreciation, amortization and accretion, net	13,610	9,077
Stock-based compensation expense	2,484	2,271
Excess tax benefits from stock-based compensation arrangements	(193)	(471)
Net amortization of premium on securities	632	845
Accretion of discount on loans	(8,276)	(7,583)
Mortgage servicing rights fair value change, net	(1,036)	514
Originations and purchases of mortgage loans held-for-sale	(736,648)	(941,651)
Proceeds from sales of mortgage loans held-for-sale	826,419	867,194
Bank owned life insurance, net of claims	(472)	(766)
Increase in trading securities, net	(1,668)	(6,605)
Net increase in brokerage customer receivables	(635)	(1,066)
Gains on mortgage loans sold	(16,287)	(20,608)
Gains on available-for-sale securities, net	(1,325)	(524)
Gains on early extinguishment of debt	(4,305)	0
Losses on sales of premises and equipment, net	21	81
Net gains on sales and fair value adjustments of other real estate owned	(119)	(549)
Increase in accrued interest receivable and other assets, net	(75,172)	(20,964)
Increase (decrease) in accrued interest payable and other liabilities, net	12,187	(48,874)
Net Cash Provided by (Used for) Operating Activities	66,362	(124,548)
Investing Activities:
Proceeds from maturities of available-for-sale securities	26,128	122,163
Proceeds from maturities of held-to-maturity securities	181	0
Proceeds from sales of available-for-sale securities	3,201	635,532
Proceeds from calls of held-to-maturity securities	98,243	0
Purchases of available-for-sale securities	(39,267)	(629,008)
Purchases of held-to-maturity securities	(125,208)	0
Purchase of Federal Home Loan Bank and Federal Reserve Bank stock, net	(11,641)	(1,366)
Net cash (paid) received for acquisitions	(17,452)	12,004
Proceeds from sales of other real estate owned	10,341	11,733
Proceeds received from (payments provided to) the FDIC related to reimbursements on covered assets	363	(2,056)
Net (increase) decrease in interest bearing deposits with banks	(204,994)	300,706
Net increase in loans	(248,893)	(399,939)
Purchases of premises and equipment, net	(8,677)	(5,902)
Net Cash (Used for) Provided by Investing Activities	(517,675)	43,867
Financing Activities:
Increase in deposit accounts	477,466	486,960
Decrease in other borrowings, net	(12,700)	(20,327)
Decrease in Federal Home Loan Bank advances, net	(58,466)	(321,565)
Redemption of junior subordinated debentures, net	(10,695)	0
Excess tax benefits from stock-based compensation arrangements	193	471
Issuance of common shares resulting from the exercise of stock options and the employee stock purchase plan	1,632	2,489
Common stock repurchases	(172)	(399)
Dividends paid	(9,440)	(6,783)
Net Cash Provided by Financing Activities	387,818	140,846
Net (Decrease) Increase in Cash and Cash Equivalents	(63,495)	60,165
Cash and Cash Equivalents at Beginning of Period	275,795	230,707
Cash and Cash Equivalents at End of Period	$ 212,300	$ 290,872