Employer Matching Contribution Per Dollar

No definition available.

Name:	tcf_DefinedContributionPlanEmployersMatchingContributionPerDollar
Namespace Prefix:	tcf_
Data Type:	xbrli:pureItemType
Balance Type:	na
Period Type:	duration

- Definition

The 401K Plan Employer Matching Contribution Vesting Period

+ References

No definition available.

+ Details

Name:	tcf_DefinedContributionPlanEmployersMatchingContributionVestingPeriod
Namespace Prefix:	tcf_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

The 401K Plan, Matching Component Requisite Service Period

+ References

No definition available.

+ Details

Name:	tcf_DefinedContributionPlanMatchingComponentRequisiteServicePeriod
Namespace Prefix:	tcf_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

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

+ References

No definition available.

+ Details

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

- Definition

Amount of cost for defined contribution plan.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-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

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

- 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_DefinedContributionPlanDisclosureLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
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

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

- Details

Name:	us-gaap_RetirementPlanNameAxis=tcf_A401KPlanAfterJanuary12016Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_RangeAxis=srt_MinimumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_RangeAxis=srt_MaximumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RetirementPlanNameAxis=tcf_A401KPlanBeforeJanuary12016Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RetirementPlanNameAxis=tcf_TheTCF401KPlanMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_StatementClassOfStockAxis=us-gaap_CommonStockMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RetirementPlanNameAxis=tcf_TCF401KSupplementalPlanMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Employee Benefit Plans - Defined Contribution Plans (Details) $ in Millions	12 Months Ended
	Dec. 31, 2018 USD ($)	Dec. 31, 2017 USD ($)	Dec. 31, 2016 USD ($)
401K Plan After January 1, 2016
Defined Contribution Plan Disclosure
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
Defined Contribution Plan Disclosure
Requisite years of service	1 year
401K Plan After January 1, 2016 \| Maximum
Defined Contribution Plan Disclosure
Maximum company contribution as a percent of covered compensation	5.00%
401K Plan Before January 1, 2016 \| Maximum
Defined Contribution Plan Disclosure
Matching contributions vesting period	5 years
TCF 401K Plan
Defined Contribution Plan Disclosure
Fair value of assets in the plan	$ 319.4
Contributions to the plan	12.3	$ 12.3	$ 12.6
TCF 401K Plan \| TCF Common Stock
Defined Contribution Plan Disclosure
Fair value of assets in the plan	152.0
TCF 401K Supplemental Plan
Defined Contribution Plan Disclosure
Maximum employee contribution as a percent of covered compensation		50.00%
Fair value of assets in the plan	51.7	$ 52.7
Contributions to the plan	1.3	1.2	$ 1.7
TCF 401K Supplemental Plan \| TCF Common Stock
Defined Contribution Plan Disclosure
Fair value of assets in the plan	$ 23.0	$ 26.0