Allowance for Loan Losses Schedule of Credit Losses Related to Covered Financing Receivables, Current Period (Details) (Covered Loans, USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014
Covered Loans
Financing Receivable, Allowance for Credit Losses [Line Items]
Balance at beginning of the period	$ 40,496	$ 44,027
Provision for Loan Losses Before Benefit Attributable to FDIC Loss Share Agreements	4,225	7,879
Benefit Attributable to FDIC Loss Share Agreements	(4,227)	(4,824)
Provision for Loan Lease and Other Losses Covered	(2)	3,055
Increase in Indemnification Asset	4,227	4,824
Allowance for Loan and Lease Losses, Write-offs	(3,207)	(1,936)
Balance at end of the period	$ 41,514	$ 49,970