Loans and Allowance for Loan Losses (Covered Allowance Activity Table) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Allowance for Covered Loan Losses [Roll Forward]
Loans and Leases Receivable, Allowance, Covered Beginning Balance				$ 36,417					$ 36,417
Provision for Loan Lease and Other Losses Covered	5,146	6,214	3,430	5,932	2,773	4,768	7,481	5,331	20,722	20,353	4,432
Loans and Leases Receivable, Allowance, Covered Ending Balance	43,255				36,417				43,255	36,417
Covered Loans [Member]
Allowance for Covered Loan Losses [Roll Forward]
Loans and Leases Receivable, Allowance, Covered Beginning Balance				36,417				13,733	36,417	13,733
Provision for loan losses before benefit attributable to FDIC loss share agreements									35,450	62,905
Benefit Attributable to FDIC Loss Share Agreements									(14,728)	(42,552)
Provision for Loan Lease and Other Losses Covered									20,722	20,353
Increase in indemnification asset									14,728	42,552
Loans charged off									(28,612)	(40,221)
Loans and Leases Receivable, Allowance, Covered Ending Balance	$ 43,255				$ 36,417				$ 43,255	$ 36,417