Goodwill and Core Deposit Intangibles (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended	12 Months Ended
Mar. 31, 2015	Mar. 31, 2014	Dec. 31, 2014
Goodwill
Beginning of period	$ 30,129us-gaap_Goodwill	$ 15,672us-gaap_Goodwill	$ 15,672us-gaap_Goodwill
Add acquisition of SharePlus			14,457us-gaap_GoodwillAcquiredDuringPeriod
End of the period	30,129us-gaap_Goodwill		30,129us-gaap_Goodwill
Core Deposit Intangibles RollForward
Beginning of period	4,148us-gaap_FiniteLivedIntangibleAssetsNet
Less amortization	(148)us-gaap_AmortizationOfIntangibleAssets	(61)us-gaap_AmortizationOfIntangibleAssets
End of period	4,000us-gaap_FiniteLivedIntangibleAssetsNet		4,148us-gaap_FiniteLivedIntangibleAssetsNet
Expected future amortization expense
Finite-Lived Intangible Assets, Net, Total	4,000us-gaap_FiniteLivedIntangibleAssetsNet		4,148us-gaap_FiniteLivedIntangibleAssetsNet
Core deposit intangibles
Core Deposit Intangibles RollForward
Beginning of period	4,148	984	984
Add acquisition of SharePlus			3,467
Less amortization	(148)		(303)
End of period	4,000		4,148
Expected future amortization expense
2015	442
2016	571
2017	525
2018	318
2019	271
Thereafter	1,873
Finite-Lived Intangible Assets, Net, Total	$ 4,000		$ 4,148
Core deposit intangibles \| Minimum
Core Deposit Intangibles RollForward
Finite-Lived Intangible Asset, Useful Life	6 years
Core deposit intangibles \| Maximum
Core Deposit Intangibles RollForward
Finite-Lived Intangible Asset, Useful Life	19 years

The aggregate expense charged against earnings to allocate the cost of intangible assets (nonphysical assets not used in production) in a systematic and rational manner to the periods expected to benefit from such assets. As a noncash expense, this element is added back to net income when calculating cash provided by or used in operations using the indirect method.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 230

-SubTopic 10

-Section 45

-Paragraph 28

-Subparagraph (b)

-URI http://asc.fasb.org/extlink&oid=31042434&loc=d3e3602-108585

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 350

-SubTopic 30

-Section 45

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-Name Accounting Standards Codification

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Amount of increase in assets, excluding financial assets, lacking physical substance with a definite life, resulting from a business combination.

+ References

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Amount of amortization expense for assets, excluding financial assets and goodwill, lacking physical substance with a finite life expected to be recognized after the fifth fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

+ References

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Amount of amortization expense for assets, excluding financial assets and goodwill, lacking physical substance with a finite life expected to be recognized during the next fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

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Amount of amortization expense for assets, excluding financial assets and goodwill, lacking physical substance with a finite life expected to be recognized during the fifth fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

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Amount of amortization expense for assets, excluding financial assets and goodwill, lacking physical substance with a finite life expected to be recognized during the fourth fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

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Amount of amortization expense for assets, excluding financial assets and goodwill, lacking physical substance with a finite life expected to be recognized during the third fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

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Amount of amortization expense for assets, excluding financial assets and goodwill, lacking physical substance with a finite life expected to be recognized during the second fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

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Amount after amortization of assets, excluding financial assets and goodwill, lacking physical substance with a finite life.

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Useful life of finite-lived intangible assets, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

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- Definition

Amount after accumulated impairment loss of an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

+ References

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-Publisher FASB

-Name Accounting Standards Codification

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Amount of increase in asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized resulting from a business combination.

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