Consolidated Statements of Cash Flows (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Cash flows from operating activities:
Net income	$ 131,961	$ 143,627	$ 132,511
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	19,712	18,477	16,380
Stock-based compensation	6,055	4,816	3,156
Provision for credit losses	16,095	25,552	53,335
Net amortization of premiums and accretion of discounts on securities and borrowings	16,229	21,124	11,871
Amortization of other intangible assets	8,258	9,783	9,315
Gains on securities transactions, net	(14,678)	(2,587)	(32,068)
Net impairment losses on securities recognized in earnings		5,247	19,968
Proceeds from sales of loans held for sale	1,083,297	999,380	366,769
Gains on sales of loans, net	(33,695)	(46,998)	(10,699)
Originations of loans held for sale	(953,125)	(923,182)	(322,281)
(Gains) losses on sales of assets, net	(10,947)	329	(426)
Net deferred income tax expense (benefit)	30,329	28,398	(16,111)
FDIC loss-share receivable (excluding reimbursements)	8,427	7,459	(13,403)
Net change in:
Trading securities	7,893	(219)	9,956
Fair value of borrowings carried at fair value	(881)	(2,574)	(1,256)
Cash surrender value of bank owned life insurance	(5,962)	(6,855)	(7,380)
Accrued interest receivable	(1,589)	5,446	(3,069)
Other assets	(17,587)	49,345	(34,977)
Accrued expenses and other liabilities	(4,428)	(13,257)	9,746
Net cash provided by operating activities	285,364	323,311	191,337
Cash flows from investing activities:
Net loan originations	(368,724)	(203,354)	(444,207)
Loans purchased	(231,008)	(136,241)	(33,293)
Investment securities held to maturity:
Purchases	(619,299)	(360,614)	(683,056)
Maturities, calls and principal repayments	473,362	705,487	582,999
Investment securities available for sale:
Purchases	(289,181)	(455,601)	(473,119)
Sales	57,003	257,497	552,486
Maturities, calls and principal repayments	183,006	248,721	280,046
Death benefit proceeds from bank owned life insurance	1,821	1,689	8,469
Proceeds from sales of real estate property and equipment	18,034	9,337	4,864
Purchases of real estate property and equipment	(14,852)	(22,735)	(16,402)
Reimbursements from the FDIC	3,812	21,935	28,372
Cash and cash equivalents acquired in acquisitions		117,587
Net cash (used in) provided by investing activities	(786,026)	183,708	(192,841)
Cash flows from financing activities:
Net change in deposits	55,244	210,623	309,488
Net change in short-term borrowings	127,132	(87,526)	20,531
Issuance of long-term borrowings	125,000
Repayments of long-term borrowings	(26,133)	(28,000)	(207,000)
Redemption of junior subordinated debentures	(142,313)	(10,000)
Cash dividends paid to common shareholders	(129,271)	(125,870)	(116,779)
Common stock issued, net	7,071	7,805	8,027
Net cash provided by (used in) financing activities	16,730	(32,968)	14,267
Net change in cash and cash equivalents	(483,932)	474,051	12,763
Cash and cash equivalents at beginning of year	853,100	379,049	366,286
Cash and cash equivalents at end of year	369,168	853,100	379,049
Supplemental disclosures of cash flow information:
Interest on deposits and borrowings	167,860	183,120	199,565
Federal and state income taxes	15,317	50,111	60,186
Supplemental schedule of non-cash investing activities:
Transfer of loans to other real estate owned	19,679	14,365	10,707
Loans transferred to loans held for sale		124,261
Transfer of investment securities held to maturity to available for sale			23,452
Non-cash assets acquired:
Investment securities available for sale		275,650
Loans		1,088,421
Premises and equipment, net		9,457
Accrued interest receivable		5,294
Goodwill		109,758
Other intangible assets, net		8,050
Other assets		72,137
Total non-cash assets acquired		1,568,767
Liabilities assumed:
Deposits		1,380,293
Short-term borrowings		29,000
Junior subordinated debentures issued to capital trusts		15,645
Accrued expenses and other liabilities		52,998
Total liabilities assumed		1,477,936
Net non-cash assets acquired		90,831
Net cash and cash equivalents acquired in acquisition		117,587
Common stock issued in acquisition		$ 208,418