XML 79 R63.htm IDEA: XBRL DOCUMENT
v3.8.0.1

Interest-Bearing Deposits (Schedule of Interest on Deposits) (Details) - USD ($) $ in Thousands | 12 Months Ended
--- | ---
Dec. 31, 2017 | Dec. 31, 2016 | Dec. 31, 2015
Interest-Bearing Deposits [Abstract] |  |  |
Interest-bearing demand deposits | $ 1,611 | $ 1,387 | $ 1,392
Savings deposits | 79 | 100 | 65
Time deposits: |  |  |
Less than $100 | 234 | 274 | 346
$100 to less than $250 | 114 | 191 | 119
$250 or more | 149 | 77 | 189
Total | $ 2,187 | $ 2,029 | $ 2,111

X
- References No definition available. + Details
Name: | cass_InterestBearingDepositsAbstract
Namespace Prefix: | cass_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Interest expense incurred on time deposits, including certificates of deposits, $100,000 or more and less than $250,000 in domestic offices. + References No definition available. + Details
Name: | cass_InterestExpenseTimeDeposits100000OrMoreAndLessThan250000
Namespace Prefix: | cass_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Interest expense incurred on time deposits, including certificates of deposits, of $250,000 or more in domestic offices. + References No definition available. + Details
Name: | cass_InterestExpenseTimeDeposits250000OrMore
Namespace Prefix: | cass_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Interest expense incurred on demand deposit accounts that represent borrowings rather than outstanding drafts. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 225 -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-04.6) -URI http://asc.fasb.org/extlink&oid=6879574&loc=d3e536633-122882 + Details
Name: | us-gaap_InterestExpenseDemandDepositAccounts
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Aggregate amount of interest expense on all deposits. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 225 -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-04.6) -URI http://asc.fasb.org/extlink&oid=6879574&loc=d3e536633-122882 + Details
Name: | us-gaap_InterestExpenseDeposits
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Interest expense incurred on all savings account deposits. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 225 -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-04.6) -URI http://asc.fasb.org/extlink&oid=6879574&loc=d3e536633-122882 + Details
Name: | us-gaap_InterestExpenseSavingsDeposits
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- References No definition available. + Details
Name: | us-gaap_InterestExpenseTimeDepositsAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Interest expense incurred on time deposits, including certificates of deposits, less than $100,000 in domestic offices. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 225 -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-04.6) -URI http://asc.fasb.org/extlink&oid=6879574&loc=d3e536633-122882 + Details
Name: | us-gaap_InterestExpenseTimeDepositsLessThan100000
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration