Consolidated Statements of Changes in Shareholders' Equity (USD $) In Thousands, except Share data	Total	Common Stock [Member]	Treasury Stock [Member]	Additional Paid-in Capital [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Loss [Member]
Balance at Dec. 31, 2011	$ 2,189,628	$ 314,136	$ (1,263)	$ 1,397,152	$ 525,657	$ (46,054)
Balance, Shares at Dec. 31, 2011		157,067,887
Total comprehensive income	64,192				61,266	2,926
Issuance of common stock in Tower Bancorp, Inc. acquisition	302,112	61,522		240,590
Issuance of common stock in Tower Bancorp, Inc. acquisition (Shares)		30,760,933
Retirement of common stock related to acquired employee benefit plans	0	(3,723)		3,723
Retirement of common stock related to acquired employee benefit plans (Shares)		(1,861,580)
Issuance of common stock and share-based awards under employee benefit plans (shares)		456,584
Issuance of common stock and share-based awards under employee benefit plans	2,922	913		2,009
Treasury stock purchased	(19)		(19)
Cash dividends paid on common stock	(14,105)				(14,105)
Balance at Jun. 30, 2012	2,544,730	372,848	(1,282)	1,643,474	572,818	(43,128)
Balance, Shares at Jun. 30, 2012		186,423,824
Balance at Dec. 31, 2012	2,595,909	373,623	(1,850)	1,645,958	615,436	(37,258)
Balance, Shares at Dec. 31, 2012		186,811,642
Total comprehensive income	59,383				88,047	(28,664)
Issuance of common stock and share-based awards under employee benefit plans (shares)		471,555
Issuance of common stock and share-based awards under employee benefit plans	4,621	943		3,678
Treasury stock purchased	(25)		(25)
Cash dividends paid on common stock	(14,948)				(14,948)
Balance at Jun. 30, 2013	$ 2,644,940	$ 374,566	$ (1,875)	$ 1,649,636	$ 688,535	$ (65,922)
Balance, Shares at Jun. 30, 2013		187,283,197