Consolidated Statements Of Cash Flows (USD $) In Thousands	9 Months Ended		12 Months Ended
	Sep. 30, 2011	Sep. 30, 2010	Dec. 31, 2010	Dec. 31, 2009
Cash Flows From Operating Activities
Net income	$ 50,246	$ 32,488
Adjustments to reconcile net income to cash provided by operating activities:
Depreciation	7,269	6,948
Amortization and impairment of other intangible assets	5,868	4,627
Net premium amortization on investment securities	8,060	4,860
Change in FDIC indemnification asset	(535)	0
Stock based compensation expense	2,551	1,702
Provision for loan losses	6,437	23,681
Net securities gains	(5,026)	(12,792)
Impairment on available-for-sale securities	499	3,308	3,927	24,795
Gain on sale leasebacks	(4,909)	(4,815)
Gain on derivatives	(702)	(1,386)
Net gains on sales and write-downs of loans and other assets	(1,459)	(1,131)
Loss on extinguishment of debt	0	2,274
Increase in cash surrender value of company owned life insurance	(3,836)	(1,333)
Residential real estate loans originated for sale	(70,232)	(44,404)
Proceeds from sale of residential real estate loans	79,089	59,635
Decrease in interest receivable	5,812	4,964
Decrease in other assets	17,220	4,529
Increase (decrease) in accrued expenses and other liabilities	15,838	1,380
Total adjustments	61,944	52,047
Net cash flows provided by operating activities	112,190	84,535
Cash Flows From Investing Activities
Cash and cash equivalents of acquired banks	398,558	0
Purchase of trust assets	(1,301)	0
Net cash paid in FDIC-assisted transaction	(151,264)	0
Purchases of investment securities available-for-sale	(490,086)	(873,737)
Purchases of investment securities held-to-maturity	0	(255,828)
Proceeds from the call/repurchase of FHLB stock	14,587	0
Proceeds from maturities, prepayments and calls of investment securities available-for-sale	379,727	752,062
Proceeds from sales of investment securities available-for-sale	454,110	339,629
Proceeds from maturities, prepayments and calls of investment securities held-to-maturity	147,050	37,376
Proceeds from sale of loans	4,743	3,377
Net principal collected from customers	105,354	163,149
Proceeds from sale of premises and equipment and other assets	413	17
Proceeds from sale leaseback of real estate	0	3,697
Purchases of premises and equipment	(4,184)	(6,215)
Net cash flows provided by investing activities	857,707	163,527
Cash Flows From Financing Activities
Noninterest-bearing demand deposits	129,007	79,061
Savings, NOW and money market deposits	(59,887)	(153,673)
Time deposits	(762,052)	(389,439)
Short-term borrowings	(27,411)	36,617
Payments for maturities on other borrowings	(725)	(75,674)
Proceeds from issuance of other borrowings	0	50,000
Payments related to retirement of debt	(211,228)	(101,356)
Cash dividends paid on common stock	(19,889)	(18,268)
Common stock repurchased	(341)	(483)
Proceeds from exercise of stock options, including tax benefit	140	12
Common stock issued	166	136
Net cash flows used in financing activities	(952,220)	(573,067)
Net increase (decrease) in cash and cash equivalents	17,677	(325,005)
Cash and cash equivalents at beginning of period	251,552	497,276	497,276
Cash and cash equivalents at end of period	269,229	172,271	251,552	497,276
Supplemental cash flow information:
Total interest paid	44,814	62,181
Total taxes paid (net of refunds)	$ 4,605	$ (2,775)