Consolidated Statements Of Cash Flows (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Cash Flows From Operating Activities
Net income	$ 91,675	$ 72,460	$ 38,214
Adjustments to reconcile net income to cash provided by operating activities:
Depreciation	11,306	9,674	8,990
Amortization and impairment of other intangible assets	7,941	8,829	6,129
Net premium amortization on investment securities	13,816	12,135	7,590
Change in FDIC idemnification assets	3,375	426	0
Stock compensation expense	3,317	3,436	2,369
Provision for loan losses	5,030	7,473	30,781
Net securities gains	(15,052)	(8,691)	(17,124)
Impairment on available-for-sale securities	1,414	1,409	3,927
Gain on sale leasebacks	(6,423)	(7,864)	(6,452)
Gain on derivatives	(820)	(974)	(1,492)
Net gains on sales and write-downs of loans and other assets	(1,547)	(2,677)	(1,410)
Loss on retirement of debt	1,949	789	6,107
Increase in cash surrender value of company owned life insurance	(6,103)	(5,295)	(1,540)
Residential real estate loans originated for sale	(86,665)	(84,303)	(57,523)
Proceeds from sale of residential real estate loans	83,912	93,757	72,773
(Increase) decrease in interest receivable	(13)	4,725	6,369
Decrease in other real estate owned	6,356	11,156	2,215
Decrease in other assets	15,452	14,345	14,582
Increase (decrease) in accrued expenses and other liabilities	(14,630)	12,276	(17,995)
Total adjustments	22,615	70,626	58,296
Net cash flows provided by operating activities	114,290	143,086	96,510
Cash Flows From Investing Activities
Cash and cash equivalents of acquired banks	78,540	398,558	0
Payments for branch divestiture	0	(106,392)	0
Purchase of trust assets	0	(1,301)	0
Net cash paid in FDIC-assisted transaction	0	(151,264)	0
Purchases of investment securities	(1,031,124)	(550,934)	(1,106,040)
Purchases of investment securities held-to-maturity	0	0	(255,828)
Purchase of loans	0	0	(7,660)
Proceeds from maturities, prepayments and calls of investment securities available-for-sale	591,735	521,553	1,046,431
Proceeds from sale of trading securities	0	1,078	0
Proceeds from sales of investment securities available-for-sale	227,566	545,995	481,471
Proceeds from maturities, prepayments and calls of investment securities held-to-maturity	31,507	154,675	150,837
Proceeds from the redemption of FHLB stock	0	18,622	4,153
Proceeds from sale of loans and leases	2,355	5,364	3,627
Reimbursements under FDIC loss share agreements	48,223	660	0
Net principal collected from (loans made to) loan customers	54,720	180,358	123,308
Proceeds from sale of premises and equipment and other assets	3,498	487	3,729
Purchases of premises and equipment and other assets	(18,712)	(11,486)	(7,460)
Net cash flows provided by (used in) investing activities	(11,692)	1,005,973	436,568
Cash Flows From Financing Activities
Deposits	(117,663)	(841,885)	(440,563)
Short-term borrowings	164,965	56,434	(32,912)
Payments for maturities on other borrowings	(3,087)	(153,383)	(75,821)
Proceeds from issuance of other borrowings	0	0	75,000
Payments related to retirement of debt	(67,949)	(211,228)	(279,649)
Cash dividends paid on common stock	(34,657)	(26,513)	(24,361)
Common stock repurchased	(3,990)	(1,526)	(705)
Proceeds from exercise of stock options, including tax benefit	717	140	12
Common stock issued	254	222	197
Net cash flows used in financing activities	(61,410)	(1,177,739)	(778,802)
Net increase (decrease) in cash and cash equivalents	41,188	(28,680)	(245,724)
Cash and cash equivalents at beginning of period	222,872	251,552	497,276
Cash and cash equivalents at end of period	$ 264,060	$ 222,872	$ 251,552