Summary of Significant Accounting Policies (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2014 segment	Dec. 31, 2013
Property, Plant and Equipment [Line Items]
Number of reportable segments	1
Required reserves on deposits maintained	$ 16.1	$ 16.8
Minimum period of consecutive contractual payments to no longer be considered in nonaccrual status	6 years
Percentage of losses from loss share agreements in noninterest income	80.00%
Finite-lived intangible assets useful life	10 years	10 years
Reimbursement period for FDIC shared-loss agreement	8 years
Furniture, Fixtures and Equipment [Member] | Minimum
Property, Plant and Equipment [Line Items]
Property plant and equipment useful life	3 years
Furniture, Fixtures and Equipment [Member] | Maximum
Property, Plant and Equipment [Line Items]
Property plant and equipment useful life	10 years
Building and Leasehold Improvements [Member] | Minimum
Property, Plant and Equipment [Line Items]
Property plant and equipment useful life	10 years
Building and Leasehold Improvements [Member] | Maximum
Property, Plant and Equipment [Line Items]
Property plant and equipment useful life	40 years
Software [Member]
Property, Plant and Equipment [Line Items]
Property plant and equipment useful life	3 years
Core Deposits [Member]
Property, Plant and Equipment [Line Items]
Finite-lived intangible assets useful life	10 years
State and Local Jurisdiction [Member]
Property, Plant and Equipment [Line Items]
Right to receive state tax credit at agreed upon rates	10 years
Residential Mortgage [Member]
Property, Plant and Equipment [Line Items]
Duration of FDIC shared-loss agreement	10 years
Covered Assets [Member]
Property, Plant and Equipment [Line Items]
Duration of FDIC shared-loss agreement	5 years