Consolidated Statements of Cash Flows (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2012	Mar. 31, 2011
OPERATING ACTIVITIES
Net income	$ 35,495	$ 61,760
Adjustments to reconcile net income to cash provided by operating activities:
Provision for loan and lease losses	30,715	44,419
Deferred tax (benefit) expense	(5,692)	1,155
Change in current taxes payable	22,857	30,455
Depreciation	16,620	16,114
Change in accrued interest payable	(2,233)	(9,074)
Change in income earned not collected	(10,190)	(9,582)
Gain on acquisitions	0	(63,474)
Securities losses	45	449
Origination of loans held for sale	(135,897)	(87,719)
Proceeds from sale of loans	158,391	130,641
Gain on sale of loans	(3,412)	(2,211)
Loss on sale of other real estate	1,495	2,074
Net amortization (accretion) of premiums and discounts	(60,822)	(34,455)
FDIC receivable for loss share agreements	130,722	128,845
Net change in other assets	23,564	143,341
Net change in other liabilities	6,487	(14,193)
Net cash provided by operating activities	208,145	338,545
INVESTING ACTIVITIES
Net change in loans outstanding	277,719	119,185
Purchases of investment securities available for sale	(1,681,584)	(141,592)
Proceeds from maturities of investment securities held to maturity	134	191
Proceeds from maturities of investment securities available for sale	1,275,014	522,893
Proceeds from sales of investment securities available for sale	0	191,697
Net change in overnight investments	(317,359)	(186,896)
Proceeds from sale of other real estate	23,853	18,067
Additions to premises and equipment	(26,610)	(12,832)
Net cash received from acquisitions	0	961,862
Net cash provided (used) by investing activities	(448,833)	1,472,575
FINANCING ACTIVITIES
Net change in time deposits	(306,338)	(367,974)
Net change in demand and other interest-bearing deposits	488,556	(1,060,414)
Net change in short-term borrowings	62,771	(217,033)
Repayment of long-term obligations	(37,781)	(216,495)
Repurchase of common stock	(1,573)	0
Cash dividends paid	(3,085)	(3,130)
Net cash provided (used) by financing activities	202,550	(1,865,046)
Change in cash and due from banks	(38,138)	(53,926)
Cash and due from banks at beginning of period	590,801	460,178
Cash and due from banks at end of period	552,663	406,252
CASH PAYMENTS FOR:
Interest	28,033	50,287
Income taxes	84	9,100
SUPPLEMENTAL DISCLOSURE OF NONCASH INVESTING AND FINANCING ACTIVITIES:
Change in unrealized securities gains (losses)	(2,898)	(9,339)
Change in fair value of cash flow hedge	389	1,717
Change in pension obligation	2,790	1,648
Transfers of loans to other real estate	26,840	46,929
Acquisitions:
Assets acquired	0	2,225,370
Liabilities assumed	0	2,161,896
Net assets acquired	$ 0	$ 63,474