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Represents the amount of expense to be charged against earnings in the next fiscal year following the latest balance sheet date, for the periodic recognition of servicing assets relative to estimated net servicing income.

+ References

No definition available.

+ Details

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- Definition

Represents the amount of expense to be charged against earnings in the year five following the latest balance sheet date, for the periodic recognition of servicing assets relative to estimated net servicing income.

+ References

No definition available.

+ Details

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- Definition

Represents the amount of expense to be charged against earnings in the year four following the latest balance sheet date, for the periodic recognition of servicing assets relative to estimated net servicing income.

+ References

No definition available.

+ Details

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Namespace Prefix:	srce_
Data Type:	xbrli:monetaryItemType
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- Definition

Represents the amount of expense to be charged against earnings in the year three following the latest balance sheet date, for the periodic recognition of servicing assets relative to estimated net servicing income.

+ References

No definition available.

+ Details

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- Definition

Represents the amount of expense to be charged against earnings in the year two following the latest balance sheet date, for the periodic recognition of servicing assets relative to estimated net servicing income.

+ References

No definition available.

+ Details

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Namespace Prefix:	srce_
Data Type:	xbrli:monetaryItemType
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- Definition

This is the result of the principal amount outstanding of total loans managed or securitized less securitized loans and loans that are in the process of being securitized.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 860

-SubTopic 20

-Section 50

-Paragraph 4

-Subparagraph (e)

-URI http://asc.fasb.org/extlink&oid=13989330&loc=d3e107314-111719

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

-Publisher FASB

-Name FASB Staff Position (FSP)

-Number FAS140-4 and FIN46(R)-8

-Paragraph B11

-Subparagraph b

-Clause 6

-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 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 140

-Paragraph 17

-Subparagraph i

-Subclause a

-Clause 4

-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.

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

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Mortgage Servicing Assets (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2012 Residential mortgage loans	Dec. 31, 2011 Residential mortgage loans	Dec. 31, 2010 Residential mortgage loans
Mortgage Servicing Assets
Unpaid principal balance		$ 921.20	$ 995.09	$ 1,080.00
Expected amortization expense on mortgage servicing rights
2013	1.00
2014	0.84
2015	0.65
2016	0.50
2017	$ 0.39