Consolidated Statements of Cash Flows (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
OPERATING ACTIVITIES
Net income	$ 55,585	$ 35,495
Adjustments to reconcile net income to cash provided by operating activities:
Provision for loan and lease losses	(18,606)	30,715
Deferred tax expense (benefit)	7,733	(5,692)
Change in current taxes payable	31,625	22,857
Depreciation	17,994	16,620
Change in accrued interest payable	(2,700)	(2,233)
Change in income earned not collected	411	(10,190)
Gain on sale of other assets	(4,085)	0
Securities losses (gains)	(58)	45
Origination of loans held for sale	(117,981)	(135,897)
Proceeds from sale of loans held for sale	121,523	158,391
Gain on sale of loans	(3,560)	(3,412)
Loss on sale of other real estate	1,350	1,495
Net amortization of premiums and discounts	(47,236)	(35,480)
FDIC receivable for loss share agreements	5,619	(18,274)
Net change in other assets	(6,980)	23,564
Net change in other liabilities	32,662	6,487
Net cash provided by operating activities	73,296	84,491
INVESTING ACTIVITIES
Net change in loans outstanding	269,428	277,719
Purchases of investment securities available for sale	(736,923)	(1,681,584)
Proceeds from maturities of investment securities held to maturity	113	134
Proceeds from maturities of investment securities available for sale	674,606	1,275,014
Proceeds from sales of investment securities available for sale	1,582	0
Net change in overnight investments	(511,052)	(317,359)
Cash received from the FDIC for loss share agreements	42,519	123,204
Proceeds from sale of other real estate	36,019	23,853
Additions to premises and equipment	(8,713)	(26,610)
Net cash (used) provided by investing activities	(232,421)	(325,629)
FINANCING ACTIVITIES
Net change in time deposits	(195,381)	(306,338)
Net change in demand and other interest-bearing deposits	174,277	488,556
Net change in short-term borrowings	4,597	62,771
Repayment of long-term obligations	(669)	(37,781)
Repurchase of common stock	(321)	(1,573)
Cash dividends paid	(2,891)	(3,085)
Net cash provided (used) by financing activities	(20,388)	202,550
Change in cash and due from banks	(179,513)	(38,588)
Cash and due from banks at beginning of period	639,730	590,801
Cash and due from banks at end of period	460,217	552,213
CASH PAYMENTS FOR:
Interest	18,422	28,033
Income taxes	3,364	84
SUPPLEMENTAL DISCLOSURE OF NONCASH INVESTING AND FINANCING ACTIVITIES:
Change in unrealized securities gains (losses)	(1,476)	(2,898)
Change in fair value of cash flow hedge	815	389
Change in pension obligation	4,304	2,790
Transfers of loans to other real estate	$ 38,008	$ 26,840