Condensed Consolidated Statements Of Cash Flows (USD $) In Thousands, unless otherwise specified	9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012
Operating Activities:
Net income	$ 135,795	$ 125,171
Adjustments to reconcile net income to net cash provided by operating activities:
Provision for loan and lease losses	24,500	14,000
Deferred tax expense	11,221	14,192
Depreciation and amortization	78,236	81,632
Stock-based compensation	7,757	6,735
Excess tax benefits from stock-based compensation	(255)	(303)
Gain on sale, net of write-down, on foreclosed and repossessed assets	(1,072)	(1,923)
(Gain) loss on sale net of write-down on premises and equipment	(59)	603
Loss on fair value adjustment of alternative investments	354	775
Loss on fair value adjustment of derivative instruments	290	12
Net gain on the sale of investment securities	(708)	(3,347)
Increase in cash surrender value of life insurance policies	(10,348)	(7,758)
Gain from life insurance policies	(1,070)	0
Gain on sale of loans held for sale	(13,584)	(14,522)
Proceeds from sale of loans held for sale	670,226	529,020
Origination of loans held for sale	(592,368)	(537,348)
Net decrease (increase) in accrued interest receivable and other assets	83,060	(14,154)
Net decrease in accrued expenses and other liabilities	(16,743)	(3,730)
Net cash provided by operating activities	375,232	189,055
Investing Activities:
Net decrease in interest-bearing deposits	37,243	16,299
Purchases of available for sale securities	(835,364)	(1,009,181)
Proceeds from maturities and principal payments of available for sale securities	621,385	627,429
Proceeds from sales of available for sale securities	44,261	148,223
Purchases of held-to-maturity securities	(702,017)	(752,030)
Proceeds from maturities and principal payments of held-to-maturity securities	587,998	571,648
Net (purchase) sale of Federal Home Loan Bank and Federal Reserve Board stock	(3,248)	1,279
Net increase in loans	(503,397)	(586,375)
Purchase of life insurance policies	0	(100,000)
Proceeds from life insurance policies	1,768	0
Proceeds from the sale of foreclosed properties and repossessed assets	5,741	7,453
Proceeds from the sale of premises and equipment	1,304	1,406
Purchases of premises and equipment	(11,247)	(14,544)
Net cash used for investing activities	(755,573)	(1,088,393)
Financing Activities:
Net increase in deposits	468,696	757,412
Proceeds from Federal Home Loan Bank advances	3,178,120	2,826,265
Repayments of Federal Home Loan Bank advances	(3,403,245)	(2,625,500)
Net increase in securities sold under agreements to repurchase and other borrowings	296,130	145,309
Repayment of long-term debt	(102,579)	(210,971)
Cash dividends paid to common shareholders	(35,176)	(21,906)
Cash dividends paid to preferred shareholders	(8,164)	(1,845)
Exercise of stock options	984	856
Excess tax benefits from stock-based compensation	255	303
Issuance of common stock	195	407
Common stock repurchased	(381)	(2,008)
Common stock warrants repurchased	(30)	(385)
Net cash provided by financing activities	394,805	867,937
Net increase (decrease) in cash and due from banks	14,464	(31,401)
Cash and due from banks at beginning of period	252,283	195,957
Cash and due from banks at end of period	266,747	164,556
Supplemental disclosure of cash flow information:
Interest paid	66,582	92,056
Income taxes paid	42,507	30,398
Noncash investing and financing activities:
Transfer of loans and leases, net to foreclosed properties and repossessed assets	9,295	5,474
Transfer of loans from portfolio to loans-held-for-sale	$ 44	$ 13,796