XML 78 R57.htm IDEA: XBRL DOCUMENT
v3.20.1

Securities (Details 1) - USD ($) $ in Thousands | Dec. 31, 2019 | Dec. 31, 2018
--- | --- | ---
Debt Securities, Available-for-sale [Line Items] |  |
Amortized Cost | $ 337,865 | $ 167,710
Gross Unrealized Gains | 3,340 | 672
Gross Unrealized Losses | (1,626) | (1,780)
Fair Value | 339,579 | 166,602
U.S. Government and Federal Agency [Member] |  |
Debt Securities, Available-for-sale [Line Items] |  |
Amortized Cost | 17,231 | 34,079
Gross Unrealized Gains | 23 | 1
Gross Unrealized Losses | (39) | (551)
Fair Value | 17,215 | 33,529
U.S. Treasury Notes and Bonds [Member] |  |
Debt Securities, Available-for-sale [Line Items] |  |
Amortized Cost | 1,994 | 1,992
Gross Unrealized Gains | 14 |
Gross Unrealized Losses |  | (45)
Fair Value | 2,008 | 1,947
State and Municipal [Member] |  |
Debt Securities, Available-for-sale [Line Items] |  |
Amortized Cost | 172,487 | 104,317
Gross Unrealized Gains | 2,694 | 544
Gross Unrealized Losses | (1,257) | (933)
Fair Value | 173,924 | 103,928
Mortgage-backed [Member] |  |
Debt Securities, Available-for-sale [Line Items] |  |
Amortized Cost | 142,504 | 21,654
Gross Unrealized Gains | 585 | 126
Gross Unrealized Losses | (329) | (205)
Fair Value | 142,760 | 21,575
Corporate [Member] |  |
Debt Securities, Available-for-sale [Line Items] |  |
Amortized Cost | 2,649 | 5,147
Gross Unrealized Gains | 24 | 1
Gross Unrealized Losses | (1) | (46)
Fair Value | 2,672 | 5,102
Trust Preferred Securities [Member] |  |
Debt Securities, Available-for-sale [Line Items] |  |
Amortized Cost | 1,000 | 500
Fair Value | 1,000 | 500
Asset-backed Securities [Member] |  |
Debt Securities, Available-for-sale [Line Items] |  |
Amortized Cost |  | 21
Fair Value |  | $ 21
Equity Securities [Member] |  |
Debt Securities, Available-for-sale [Line Items] |  |
Amortized Cost | 2,426 |
Fair Value | $ 2,851 |

X
- Definition Amount of investment in debt and equity securities categorized neither as held-to-maturity nor trading. + References No definition available. + Details
Name: | us-gaap_AvailableForSaleSecurities
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amount before tax of unrealized gain in accumulated other comprehensive income (AOCI) on investments in debt and equity securities classified as available-for-sale. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=118939692&loc=d3e27161-111563 + Details
Name: | us-gaap_AvailableForSaleSecuritiesAccumulatedGrossUnrealizedGainBeforeTax
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Amount before tax of unrealized loss in accumulated other comprehensive income (AOCI) on investments in debt and equity securities classified as available-for-sale. + References No definition available. + Details
Name: | us-gaap_AvailableForSaleSecuritiesAccumulatedGrossUnrealizedLossBeforeTax
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition This item represents the cost of debt and equity securities, which are categorized neither as held-to-maturity nor trading, net of adjustments including accretion, amortization, collection of cash, previous other-than-temporary impairments recognized in earnings (less any cumulative-effect adjustments recognized, as defined), and fair value hedge accounting adjustments, if any. + References No definition available. + Details
Name: | us-gaap_AvailableForSaleSecuritiesAmortizedCost
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. + References No definition available. + Details
Name: | us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | us-gaap_FinancialInstrumentAxis=us-gaap_USTreasuryAndGovernmentMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancialInstrumentAxis=us-gaap_USTreasurySecuritiesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancialInstrumentAxis=us-gaap_USStatesAndPoliticalSubdivisionsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancialInstrumentAxis=us-gaap_MortgageBackedSecuritiesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancialInstrumentAxis=us-gaap_CorporateDebtSecuritiesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancialInstrumentAxis=cofs_TrustPreferredSecuritiesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancialInstrumentAxis=us-gaap_AssetBackedSecuritiesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancialInstrumentAxis=us-gaap_EquitySecuritiesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |