XML 45 R47.htm IDEA: XBRL DOCUMENT v2.4.1.9

Investment in Securities (Narrative) (Details) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Investment in Securities [Abstract]
Number of securities that had an unrealized loss	20us-gaap_AvailableforsaleSecuritiesInUnrealizedLossPositionsQualitativeDisclosureNumberOfPositions1	102us-gaap_AvailableforsaleSecuritiesInUnrealizedLossPositionsQualitativeDisclosureNumberOfPositions1
Number of securities that had an unrealized loss, greater than 12 months	12us-gaap_AvailableforsaleSecuritiesInUnrealizedLossPositionsQualitativeDisclosureNumberOfPositionsGreaterThanOrEqualToOneYear	3us-gaap_AvailableforsaleSecuritiesInUnrealizedLossPositionsQualitativeDisclosureNumberOfPositionsGreaterThanOrEqualToOneYear
Percentage of total securities	6.00%cass_AvailableForSaleSecuritiesInUnrealizedLossPositionsQualitativeDisclosurePercentage
Premium related to purchase of state and political subdivisions	$ 5,085,000cass_ProceedsFromPurchaseOfStateAndPoliticalSubdivisions	$ 4,450,000cass_ProceedsFromPurchaseOfStateAndPoliticalSubdivisions
Securities pledged as collateral	3,750,000us-gaap_AvailableForSaleSecuritiesPledgedAsCollateral	3,750,000us-gaap_AvailableForSaleSecuritiesPledgedAsCollateral
Proceeds from sales of securities available-for-sale	587,000us-gaap_ProceedsFromSaleOfAvailableForSaleSecurities	95,742,000us-gaap_ProceedsFromSaleOfAvailableForSaleSecurities	69,747,000us-gaap_ProceedsFromSaleOfAvailableForSaleSecurities
Gross realized gains	23,000us-gaap_AvailableForSaleSecuritiesGrossRealizedGains	4,295,000us-gaap_AvailableForSaleSecuritiesGrossRealizedGains	2,646,000us-gaap_AvailableForSaleSecuritiesGrossRealizedGains
Gross realized losses	$ 0us-gaap_AvailableForSaleSecuritiesGrossRealizedLosses	$ 271,000us-gaap_AvailableForSaleSecuritiesGrossRealizedLosses	$ 11,000us-gaap_AvailableForSaleSecuritiesGrossRealizedLosses

X

- Definition

The percentage of the number of investment positions in the available-for-sale investments determined to be temporarily impaired.

+ References

No definition available.

+ Details

Name:	cass_AvailableForSaleSecuritiesInUnrealizedLossPositionsQualitativeDisclosurePercentage
Namespace Prefix:	cass_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

X

- Definition

The premium related to the purchase of state and political subdivisions.

+ References

No definition available.

+ Details

Name:	cass_ProceedsFromPurchaseOfStateAndPoliticalSubdivisions
Namespace Prefix:	cass_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

X

- Definition

This item represents the gross profit realized on the sale of debt or equity securities categorized neither as held-to-maturity nor trading securities.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 320

-SubTopic 10

-Section 50

-Paragraph 9

-Subparagraph (a)

-URI http://asc.fasb.org/extlink&oid=27724398&loc=d3e27357-111563

+ Details

Name:	us-gaap_AvailableForSaleSecuritiesGrossRealizedGains
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

X

- Definition

This item represents the gross loss realized on the sale of debt or equity securities categorized neither as held-to-maturity nor trading securities.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 320

-SubTopic 10

-Section 50

-Paragraph 9

-Subparagraph (a)

-URI http://asc.fasb.org/extlink&oid=27724398&loc=d3e27357-111563

+ Details

Name:	us-gaap_AvailableForSaleSecuritiesGrossRealizedLosses
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

X

- Definition

Number of investment positions in available-for-sale investments in a continuous unrealized loss position for which an other-than-temporary impairment (OTTI) has not been recognized in the income statement.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 320

-SubTopic 10

-Section 50

-Paragraph 6

-Subparagraph (b)(3)

-URI http://asc.fasb.org/extlink&oid=27724398&loc=d3e27290-111563

+ Details

Name:	us-gaap_AvailableforsaleSecuritiesInUnrealizedLossPositionsQualitativeDisclosureNumberOfPositions1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

X

- Definition

Number of investment positions in available-for-sale investments that have been in a continuous unrealized loss position for greater than or equal to a year for which an other-than-temporary impairment (OTTI) has not been recognized in the income statement.

+ References

No definition available.

+ Details

Name:	us-gaap_AvailableforsaleSecuritiesInUnrealizedLossPositionsQualitativeDisclosureNumberOfPositionsGreaterThanOrEqualToOneYear
Namespace Prefix:	us-gaap_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

X

- Definition

The fair value of available-for-sale securities that serve as collateral for borrowings.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 310

-SubTopic 10

-Section 50

-Paragraph 5

-URI http://asc.fasb.org/extlink&oid=35738203&loc=d3e5086-111524

+ Details

Name:	us-gaap_AvailableForSaleSecuritiesPledgedAsCollateral
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

X

- Details

Name:	us-gaap_InvestmentsDebtAndEquitySecuritiesAbstract
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

X

- Definition

The cash inflow associated with the sale of debt and equity securities classified as available-for-sale securities.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Glossary Investing Activities

-URI http://asc.fasb.org/extlink&oid=6516133



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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 320

-SubTopic 10

-Section 45

-Paragraph 11

-URI http://asc.fasb.org/extlink&oid=6871852&loc=d3e26853-111562



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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 230

-SubTopic 10

-Section 45

-Paragraph 12

-Subparagraph (a),(b)

-URI http://asc.fasb.org/extlink&oid=31042434&loc=d3e3179-108585

+ Details

Name:	us-gaap_ProceedsFromSaleOfAvailableForSaleSecurities
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration