Condensed Consolidated Statements Of Cash Flows (USD $) In Thousands, unless otherwise specified	6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012
Operating Activities:
Net income	$ 88,490	$ 80,178
Adjustments to reconcile net income to net cash provided by operating activities:
Provision for loan and lease losses	16,000	9,000
Deferred tax expense	13,614	18,341
Depreciation and amortization	52,719	51,768
Stock-based compensation	5,595	4,171
Excess tax benefits from stock-based compensation	(93)	(1,076)
Gain on sale, net of write-down, on foreclosed and repossessed assets	(534)	(1,484)
(Gain) loss on sale net of write-down on premises and equipment	(160)	173
Loss on fair value adjustment of alternative investments	284	257
Gain on fair value adjustment of derivative instruments	(160)	(217)
Net gain on the sale of available for sale securities	(439)	(2,537)
Increase in cash surrender value of life insurance policies	(6,832)	(5,078)
Gain from life insurance policies	(1,070)	0
Gain on sale of loans held for sale	(12,919)	(8,007)
Proceeds from sale of loans held for sale	470,323	310,640
Origination of loans held for sale	(435,315)	(329,690)
Net decrease (increase) in accrued interest receivable and other assets	80,044	(21,377)
Net decrease in accrued expenses and other liabilities	(23,552)	(9,462)
Net cash provided by operating activities	245,995	95,600
Investing Activities:
Net decrease in interest-bearing deposits	22,834	22,464
Purchases of available for sale securities	(631,271)	(634,113)
Proceeds from maturities and principal payments of available for sale securities	426,129	383,737
Proceeds from sales of available for sale securities	36,521	45,855
Purchases of held-to-maturity securities	(446,497)	(459,212)
Proceeds from maturities and principal payments of held-to-maturity securities	414,444	366,692
Net (purchase) sale of Federal Home Loan Bank and Federal Reserve Board stock	(3,248)	1,279
Net increase in loans	(252,613)	(364,202)
Proceeds from life insurance policies	1,768	0
Proceeds from the sale of foreclosed properties and repossessed assets	4,056	5,733
Proceeds from the sale of premises and equipment	1,169	887
Purchases of premises and equipment	(4,816)	(7,678)
Net cash used for investing activities	(431,524)	(638,558)
Financing Activities:
Net increase in deposits	304,740	317,902
Proceeds from Federal Home Loan Bank advances	1,925,000	1,826,265
Repayments of Federal Home Loan Bank advances	(2,125,083)	(1,549,064)
Net increase in securities sold under agreements to repurchase and other borrowings	137,189	38,672
Repayment of long-term debt	(102,579)	(74,901)
Cash dividends paid to common shareholders	(21,868)	(13,148)
Cash dividends paid to preferred shareholders	(5,525)	(1,230)
Exercise of stock options	377	422
Excess tax benefits from stock-based compensation	93	1,076
Issuance of common stock	169	250
Common stock repurchased	(169)	(1,677)
Common stock warrants repurchased	(30)	(337)
Net cash provided by financing activities	112,314	544,230
Net (decrease) increase in cash and due from banks	(73,215)	1,272
Cash and due from banks at beginning of period	252,283	195,957
Cash and due from banks at end of period	179,068	197,229
Supplemental disclosure of cash flow information:
Interest paid	48,081	64,831
Income taxes paid	21,620	9,793
Noncash investing and financing activities:
Transfer of loans and leases, net to foreclosed properties and repossessed assets	3,988	3,656
Transfer of loans from portfolio to loans-held-for-sale	$ 248	$ 6,816