Employer Matching Contribution Per Dollar

No definition available.

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Data Type:	xbrli:pureItemType
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- Definition

The 401K Plan, Matching Component Requisite Service Period

+ References

No definition available.

+ Details

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- Definition

Represents the total fair value of assets under a deferred compensation arrangement.

+ References

No definition available.

+ Details

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Namespace Prefix:	tcf_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- 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

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Data Type:	xbrli:stringItemType
Balance Type:	na
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- Definition

Amount of cost for defined contribution plan.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 70
-Section 50
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=49170846&loc=d3e28014-114942

+ Details

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

- Definition

Percentage of employees' gross pay for which the employer contributes a matching contribution to a defined contribution plan.

+ References

No definition available.

+ Details

Name:	us-gaap_DefinedContributionPlanEmployerMatchingContributionPercent
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Maximum percentage of employee gross pay the employee may contribute to a defined contribution plan.

+ References

No definition available.

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Details

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- Details

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- Details

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- Details

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- Details

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Retirement Plans - 401(k) Savings Plans (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
401K Plan After January 1, 2016
Employee Benefit Plans
Maximum employee contribution as a percent of covered compensation	50.00%
Employer matching contribution rate per dollar	1
401K Plan After January 1, 2016 \| Minimum
Employee Benefit Plans
Requisite years of service	180 days
401K Plan After January 1, 2016 \| Maximum
Employee Benefit Plans
Maximum company contribution as a percent of covered compensation	5.00%
TCF 401K Plan
Employee Benefit Plans
Fair value of assets in the plan	$ 593.5
Contributions to the plan	20.8	$ 16.4	$ 12.3
TCF 401K Plan \| Common Stock
Employee Benefit Plans
Fair value of assets in the plan	$ 146.8