Intangible Assets (Details) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2013
Summary of intangible assets
Gross Carrying Amount	$ 19,953
Accumulated Amortization	(8,358)
Net Carrying Amount	11,595
Core deposit intangibles [Member]
Summary of intangible assets
Gross Carrying Amount	13,473
Accumulated Amortization	(6,171)
Net Carrying Amount	7,302
Customer relationship intangibles [Member]
Summary of intangible assets
Gross Carrying Amount	5,657
Accumulated Amortization	(2,073)
Net Carrying Amount	3,584
Mortgage Servicing Intangibles [Member]
Summary of intangible assets
Gross Carrying Amount	823
Accumulated Amortization	(114)
Net Carrying Amount	$ 709

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

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 350

-SubTopic 30

-Section 50

-Paragraph 2

-Subparagraph (a)(1)

-URI http://asc.fasb.org/extlink&oid=7658586&loc=d3e16323-109275

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 142

-Paragraph 45

-Subparagraph a(1)

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Name:	us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant