Covered Loans Receivable (Nonaccrual Loans) (Details) (Covered Nonaccrual Loans, USD $) In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross covered nonaccrual loans	$ 4,062	$ 7
Commercial Business
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross covered nonaccrual loans	3,877	0
Commercial Business | Commercial and Industrial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross covered nonaccrual loans	2,321	0
Commercial Business | Owner-occupied Commercial Real Estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross covered nonaccrual loans	1,132	0
Commercial Business | Non-owner Occupied Commercial Real Estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross covered nonaccrual loans	424	0
Real Estate Construction and Land Development [Member] | One-to-four Family Residential
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross covered nonaccrual loans	179	0
Consumer
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross covered nonaccrual loans	$ 6	$ 7