Loans and Allowance for Loan Losses (Details 1) (USD $) In Thousands, unless otherwise specified			3 Months Ended										3 Months Ended		3 Months Ended		3 Months Ended
	Mar. 31, 2012	Dec. 31, 2011	Mar. 31, 2012 Allowance for loan losses [Member]	Mar. 31, 2011 Allowance for loan losses [Member]	Mar. 31, 2012 Allowance for loan losses [Member] Commercial Loans [Member]	Mar. 31, 2011 Allowance for loan losses [Member] Commercial Loans [Member]	Mar. 31, 2012 Allowance for loan losses [Member] Residential mortgage Loans [Member]	Mar. 31, 2011 Allowance for loan losses [Member] Residential mortgage Loans [Member]	Mar. 31, 2012 Allowance for loan losses [Member] Consumer loan [Member]	Mar. 31, 2011 Allowance for loan losses [Member] Consumer loan [Member]	Mar. 31, 2012 Loans [Member]	Mar. 31, 2011 Loans [Member]	Mar. 31, 2012 Loans [Member] Commercial Loans [Member]	Mar. 31, 2011 Loans [Member] Commercial Loans [Member]	Mar. 31, 2012 Loans [Member] Residential mortgage Loans [Member]	Mar. 31, 2011 Loans [Member] Residential mortgage Loans [Member]	Mar. 31, 2012 Loans [Member] Consumer loan [Member]	Mar. 31, 2011 Loans [Member] Consumer loan [Member]
Allowance for loan losses:
Loans and Leases receivable, Allowance, Beginning Balance	$ 142,337	$ 124,881	$ 124,881	$ 81,997	$ 78,414	$ 56,859	$ 13,918	$ 4,626	$ 32,549	$ 20,512		$ 4,840,975		$ 3,089,365		$ 630,092		$ 1,121,518
Charge-offs			(29,615)	(9,079)	(24,919)	(4,754)	(1,118)	(1,142)	(3,578)	(3,183)
Recoveries			6,132	2,262	4,212	574	397	771	1,523	917
Net Provision for loan losses			10,015	8,822	10,473	6,837	3,639	687	(4,097)	1,298
Increase in indemnification asset			30,924	10,354	15,758	10,354	12,397		2,769
Loans and Leases receivable, Allowance, Ending Balance	142,337	124,881	142,337	94,356	83,938	69,870	29,233	4,942	29,166	19,544	11,130,273	4,840,975	7,992,375	3,089,365	1,511,349	630,092	1,626,549	1,121,518
Ending balance: Individually evaluated for impairment			11,199	11,937	10,634	10,627	565	1,310			56,422	59,351	48,338	53,093	8,084	6,258
Ending balance: Collectively evaluated for impairment			131,138	82,419	73,304	59,243	28,668	3,632	29,166	19,544	10,440,067	4,004,530	7,719,514	2,673,605	1,227,409	353,793	1,493,144	977,132
Ending balance: Covered loans with deteriorated credit quality			57,842	10,899	18,446	10,899	22,074		17,322
Loans:
Impairment of covered loans											633,784	777,094	224,523	362,667	275,856	270,041	133,405	144,386
Acquired loans											$ 5,045,482		$ 4,065,324		$ 671,275		$ 308,883