Goodwill and Other Intangible Assets (Details 2) (USD $) In Thousands, unless otherwise specified	3 Months Ended
Mar. 31, 2012
Core deposit intangibles [Member]
Estimated future amortization expense
Three months ending December 31, 2011	$ 2,400
Year ending December 31, 2012	3,100
Year ending December 31, 2013	2,900
Year ending December 31, 2014	1,400
Year ending December 31, 2015	300
Year ending December 31, 2016	100
Other Intangibles [Member]
Estimated future amortization expense
Three months ending December 31, 2011	700
Year ending December 31, 2012	900
Year ending December 31, 2013	900
Year ending December 31, 2014	800
Year ending December 31, 2015	800
Year ending December 31, 2016	800
Mortgage Service Rights [Member]
Estimated future amortization expense
Three months ending December 31, 2011	11,100
Year ending December 31, 2012	11,700
Year ending December 31, 2013	8,700
Year ending December 31, 2014	6,700
Year ending December 31, 2015	5,200
Year ending December 31, 2016	$ 4,100

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The amount of amortization expense expected to be recognized during the remainder of the current fiscal year.

+ References

No definition available.

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- Definition

The amount of amortization expense expected to be recognized during year five of the five succeeding fiscal years.

+ References

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 142

-Paragraph 45

-Subparagraph a(3)

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009.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.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 350

-SubTopic 30

-Section 50

-Paragraph 2

-Subparagraph (a)(3)

-URI http://asc.fasb.org/extlink&oid=6905858&loc=d3e16323-109275

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- Definition

The amount of amortization expense expected to be recognized during year four of the five succeeding fiscal years.

+ References

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- Definition

The amount of amortization expense expected to be recognized during year one of the five succeeding fiscal years.

+ References

+ Details

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The amount of amortization expense expected to be recognized during year three of the five succeeding fiscal years.

+ References

+ Details

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- Definition

The amount of amortization expense expected to be recognized during year two of the five succeeding fiscal years.

+ References

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