Loan Portfolio and Allowance for Credit Losses, Risk Category of Loans (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
Mar. 31, 2025	Mar. 31, 2024	Dec. 31, 2024
Credit Risk Profile, Segregated by Class [Abstract]
Total loans	$ 5,116,137		$ 5,098,058
Current-period Gross writeoffs	124	$ 161
Commercial [Member]
Credit Risk Profile, Segregated by Class [Abstract]
Total loans	302,753		286,857
Current-period Gross writeoffs	4	0
Commercial [Member] \| Commercial Real Estate [Member]
Credit Risk Profile, Segregated by Class [Abstract]
2025/2024	17,533		47,687
2024/2023	48,481		54,877
2023/2022	52,782		74,339
2022/2021	73,225		22,215
2021/2020	22,085		15,036
Prior	64,301		50,977
Revolving Loans Amortized Cost Basis	4,893		2,169
Revolving Loan Converted to Term	0		0
Total loans	283,300		267,300
2024/2023	0		0
2023/2022	0		0
2022/2021	0		10
2021/2020	0		431
2020/2019	0		0
Prior	0		0
Revolving Loans Amortized Cost Basis Writeoffs	0		0
Revolving Loan Converted to Term Writeoffs	0		0
Current-period Gross writeoffs	0		441
Commercial [Member] \| Commercial Real Estate [Member] \| Pass [Member]
Credit Risk Profile, Segregated by Class [Abstract]
2025/2024	17,533		47,687
2024/2023	48,481		54,877
2023/2022	52,782		73,094
2022/2021	71,625		22,215
2021/2020	22,085		15,014
Prior	63,390		50,052
Revolving Loans Amortized Cost Basis	4,893		2,169
Revolving Loan Converted to Term	0		0
Total loans	280,789		265,108
Commercial [Member] \| Commercial Real Estate [Member] \| Special Mention [Member]
Credit Risk Profile, Segregated by Class [Abstract]
2025/2024	0		0
2024/2023	0		0
2023/2022	0		242
2022/2021	241		0
2021/2020	0		0
Prior	0		0
Revolving Loans Amortized Cost Basis	0		0
Revolving Loan Converted to Term	0		0
Total loans	241		242
Commercial [Member] \| Commercial Real Estate [Member] \| Substandard [Member]
Credit Risk Profile, Segregated by Class [Abstract]
2025/2024	0		0
2024/2023	0		0
2023/2022	0		1,003
2022/2021	1,359		0
2021/2020	0		22
Prior	873		887
Revolving Loans Amortized Cost Basis	0		0
Revolving Loan Converted to Term	0		0
Total loans	2,232		1,912
Commercial [Member] \| Commercial Real Estate [Member] \| Doubtful [Member]
Credit Risk Profile, Segregated by Class [Abstract]
2025/2024	0		0
2024/2023	0		0
2023/2022	0		0
2022/2021	0		0
2021/2020	0		0
Prior	38		38
Revolving Loans Amortized Cost Basis	0		0
Revolving Loan Converted to Term	0		0
Total loans	38		38
Commercial [Member] \| Other [Member]
Credit Risk Profile, Segregated by Class [Abstract]
2025/2024	877		1,855
2024/2023	2,543		7,417
2023/2022	7,128		1,796
2022/2021	1,716		429
2021/2020	330		184
Prior	2,301		2,242
Revolving Loans Amortized Cost Basis	4,558		5,634
Revolving Loan Converted to Term	0		0
Total loans	19,453		19,557
2024/2023	0		0
2023/2022	0		0
2022/2021	0		0
2021/2020	0		0
2020/2019	4		0
Prior	0		0
Revolving Loans Amortized Cost Basis Writeoffs	0		0
Revolving Loan Converted to Term Writeoffs	0		0
Current-period Gross writeoffs	4		0
Commercial [Member] \| Other [Member] \| Pass [Member]
Credit Risk Profile, Segregated by Class [Abstract]
2025/2024	877		1,842
2024/2023	2,531		7,417
2023/2022	7,128		1,796
2022/2021	1,716		407
2021/2020	324		184
Prior	2,203		2,108
Revolving Loans Amortized Cost Basis	4,520		5,634
Revolving Loan Converted to Term	0		0
Total loans	19,299		19,388
Commercial [Member] \| Other [Member] \| Special Mention [Member]
Credit Risk Profile, Segregated by Class [Abstract]
2025/2024	0		0
2024/2023	0		0
2023/2022	0		0
2022/2021	0		0
2021/2020	0		0
Prior	0		0
Revolving Loans Amortized Cost Basis	0		0
Revolving Loan Converted to Term	0		0
Total loans	0		0
Commercial [Member] \| Other [Member] \| Substandard [Member]
Credit Risk Profile, Segregated by Class [Abstract]
2025/2024	0		13
2024/2023	12		0
2023/2022	0		0
2022/2021	0		22
2021/2020	6		0
Prior	98		134
Revolving Loans Amortized Cost Basis	38		0
Revolving Loan Converted to Term	0		0
Total loans	154		169
Commercial [Member] \| Other [Member] \| Doubtful [Member]
Credit Risk Profile, Segregated by Class [Abstract]
2025/2024	0
2024/2023	0
2023/2022	0
2022/2021	0
2021/2020	0
Prior	0
Revolving Loans Amortized Cost Basis	0
Revolving Loan Converted to Term	0
Total loans	0
Real Estate Mortgage - 1 to 4 Family [Member]
Credit Risk Profile, Segregated by Class [Abstract]
Total loans	4,800,367		4,797,563
Current-period Gross writeoffs	80	117
Real Estate Mortgage - 1 to 4 Family [Member] \| First Mortgages [Member]
Credit Risk Profile, Segregated by Class [Abstract]
2025/2024	55,087		313,944
2024/2023	319,051		399,709
2023/2022	394,372		536,093
2022/2021	528,877		822,674
2021/2020	808,026		682,083
Prior	2,217,485		1,576,122
Revolving Loans Amortized Cost Basis	1,373		938
Revolving Loan Converted to Term	0		0
Total loans	4,324,271		4,331,563
2024/2023	0		194
2023/2022	0		0
2022/2021	0		0
2021/2020	0		0
2020/2019	0		0
Prior	80		18
Revolving Loans Amortized Cost Basis Writeoffs	0		0
Revolving Loan Converted to Term Writeoffs	0		0
Current-period Gross writeoffs	80		212
Real Estate Mortgage - 1 to 4 Family [Member] \| First Mortgages [Member] \| Performing [Member]
Credit Risk Profile, Segregated by Class [Abstract]
2025/2024	55,087		313,944
2024/2023	319,051		398,722
2023/2022	393,819		535,702
2022/2021	528,695		821,804
2021/2020	807,063		681,840
Prior	2,204,696		1,563,659
Revolving Loans Amortized Cost Basis	1,373		938
Revolving Loan Converted to Term	0		0
Total loans	4,309,784		4,316,609
Real Estate Mortgage - 1 to 4 Family [Member] \| First Mortgages [Member] \| Nonperforming [Member]
Credit Risk Profile, Segregated by Class [Abstract]
2025/2024	0		0
2024/2023	0		987
2023/2022	553		391
2022/2021	182		870
2021/2020	963		243
Prior	12,789		12,463
Revolving Loans Amortized Cost Basis	0		0
Revolving Loan Converted to Term	0		0
Total loans	14,487		14,954
Real Estate Mortgage - 1 to 4 Family [Member] \| Home Equity Loans [Member]
Credit Risk Profile, Segregated by Class [Abstract]
2025/2024	2,300		6,621
2024/2023	6,103		8,586
2023/2022	8,262		5,509
2022/2021	5,290		6,490
2021/2020	6,355		5,066
Prior	27,980		24,467
Revolving Loans Amortized Cost Basis	0		0
Revolving Loan Converted to Term	0		0
Total loans	56,290		56,739
2024/2023	0		0
2023/2022	0		0
2022/2021	0		0
2021/2020	0		0
2020/2019	0		0
Prior	0		0
Revolving Loans Amortized Cost Basis Writeoffs	0		0
Revolving Loan Converted to Term Writeoffs	0		0
Current-period Gross writeoffs	0		0
Real Estate Mortgage - 1 to 4 Family [Member] \| Home Equity Loans [Member] \| Performing [Member]
Credit Risk Profile, Segregated by Class [Abstract]
2025/2024	2,300		6,621
2024/2023	6,103		8,586
2023/2022	8,262		5,354
2022/2021	5,136		6,490
2021/2020	6,355		5,066
Prior	27,614		24,096
Revolving Loans Amortized Cost Basis	0		0
Revolving Loan Converted to Term	0		0
Total loans	55,770		56,213
Real Estate Mortgage - 1 to 4 Family [Member] \| Home Equity Loans [Member] \| Nonperforming [Member]
Credit Risk Profile, Segregated by Class [Abstract]
2025/2024	0		0
2024/2023	0		0
2023/2022	0		155
2022/2021	154		0
2021/2020	0		0
Prior	366		371
Revolving Loans Amortized Cost Basis	0		0
Revolving Loan Converted to Term	0		0
Total loans	520		526
Real Estate Mortgage - 1 to 4 Family [Member] \| Home Equity Lines of Credit [Member]
Credit Risk Profile, Segregated by Class [Abstract]
2025/2024	744		4,793
2024/2023	4,213		1,558
2023/2022	1,102		1,180
2022/2021	1,365		887
2021/2020	1,048		46
Prior	17,663		17,127
Revolving Loans Amortized Cost Basis	393,671		383,670
Revolving Loan Converted to Term	0		0
Total loans	419,806		409,261
2024/2023	0		0
2023/2022	0		0
2022/2021	0		0
2021/2020	0		0
2020/2019	0		0
Prior	0		116
Revolving Loans Amortized Cost Basis Writeoffs	0		0
Revolving Loan Converted to Term Writeoffs	0		0
Current-period Gross writeoffs	0		116
Real Estate Mortgage - 1 to 4 Family [Member] \| Home Equity Lines of Credit [Member] \| Performing [Member]
Credit Risk Profile, Segregated by Class [Abstract]
2025/2024	744		4,793
2024/2023	4,213		1,558
2023/2022	1,102		1,110
2022/2021	1,295		887
2021/2020	1,048		46
Prior	15,117		14,595
Revolving Loans Amortized Cost Basis	393,365		383,425
Revolving Loan Converted to Term	0		0
Total loans	416,884		406,414
Real Estate Mortgage - 1 to 4 Family [Member] \| Home Equity Lines of Credit [Member] \| Nonperforming [Member]
Credit Risk Profile, Segregated by Class [Abstract]
2025/2024	0		0
2024/2023	0		0
2023/2022	0		70
2022/2021	70		0
2021/2020	0		0
Prior	2,546		2,532
Revolving Loans Amortized Cost Basis	306		245
Revolving Loan Converted to Term	0		0
Total loans	2,922		2,847
Installment [Member]
Credit Risk Profile, Segregated by Class [Abstract]
2025/2024	771		2,862
2024/2023	2,881		5,518
2023/2022	4,860		2,843
2022/2021	2,507		724
2021/2020	603		123
Prior	456		540
Revolving Loans Amortized Cost Basis	939		1,028
Revolving Loan Converted to Term	0		0
Total loans	13,017		13,638
2024/2023	0		0
2023/2022	15		53
2022/2021	7		47
2021/2020	15		35
2020/2019	0		4
Prior	3		31
Revolving Loans Amortized Cost Basis Writeoffs	0		0
Revolving Loan Converted to Term Writeoffs	0		0
Current-period Gross writeoffs	40	$ 44	170
Installment [Member] \| Performing [Member]
Credit Risk Profile, Segregated by Class [Abstract]
2025/2024	771		2,846
2024/2023	2,831		5,513
2023/2022	4,856		2,788
2022/2021	2,471		705
2021/2020	584		123
Prior	422		505
Revolving Loans Amortized Cost Basis	939		1,028
Revolving Loan Converted to Term	0		0
Total loans	12,874		13,508
Installment [Member] \| Nonperforming [Member]
Credit Risk Profile, Segregated by Class [Abstract]
2025/2024	0		16
2024/2023	50		5
2023/2022	4		55
2022/2021	36		19
2021/2020	19		0
Prior	34		35
Revolving Loans Amortized Cost Basis	0		0
Revolving Loan Converted to Term	0		0
Total loans	$ 143		$ 130

No definition available.

Name:	trst_FinancingReceivableRiskCategoryOfLoansByClassAbstract
Namespace Prefix:	trst_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount of writeoff of financing receivable, charged against allowance for credit loss.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/otherTransitionRef
-Topic 310
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 11B
-Subparagraph (c)(3)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481962/310-10-50-11B

Reference 2: http://www.xbrl.org/2003/role/exampleRef
-Topic 326
-SubTopic 20
-Name Accounting Standards Codification
-Section 55
-Paragraph 79
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479294/326-20-55-79

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 326
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 6
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479319/326-20-50-6

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Topic 326
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 13
-Subparagraph (d)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479319/326-20-50-13

+ Details

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

- Definition

Amortized cost of financing receivable originated more than five years prior to current fiscal year. Excludes net investment in lease.

+ References

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Topic 326
-SubTopic 20
-Name Accounting Standards Codification
-Section 55
-Paragraph 79
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479294/326-20-55-79

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 326
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 6
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479319/326-20-50-6

+ Details

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

- Definition

Amortized cost of financing receivable originated four years prior to current fiscal year. Excludes net investment in lease.

+ References

+ Details

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

- Definition

Amortized cost of financing receivable originated in current fiscal year. Excludes net investment in lease.

+ References

+ Details

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

- Definition

Amortized cost of financing receivable originated in fiscal year prior to current fiscal year. Excludes net investment in lease.

+ References

+ Details

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

- Definition

Amount of writeoff of financing receivable originated more than five years before current fiscal year. Excludes net investment in lease.

+ References

+ Details

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

- Definition

Amortized cost of financing receivable originated three years prior to current fiscal year. Excludes net investment in lease.

+ References

+ Details

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

- Definition

Amortized cost of financing receivable originated two years prior to current fiscal year. Excludes net investment in lease.

+ References

+ Details

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

- Definition

Amortized cost of financing receivable that can be withdrawn, repaid, and redrawn.

+ References

+ Details

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

- Definition

Amortized cost of revolving financing receivable converted to term loan.

+ References

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Topic 326
-SubTopic 20
-Name Accounting Standards Codification
-Section 55
-Paragraph 79
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479294/326-20-55-79

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 326
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 6A
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479319/326-20-50-6A

+ Details

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

- Definition

Amount of writeoff of revolving financing receivable converted to term loan.

+ References

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Topic 326
-SubTopic 20
-Name Accounting Standards Codification
-Section 55
-Paragraph 79
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479294/326-20-55-79

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 326
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 6A
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479319/326-20-50-6A

+ Details

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

- Definition

Amount of writeoff of financing receivable that can be withdrawn, repaid, and redrawn.

+ References

+ Details

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

- Definition

Amount of writeoff of financing receivable originated four years before current fiscal year. Excludes net investment in lease.

+ References

+ Details

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

- Definition

Amount of writeoff of financing receivable originated three years before current fiscal year. Excludes net investment in lease.

+ References

+ Details

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

- Definition

Amount of writeoff of financing receivable originated in current fiscal year. Excludes net investment in lease.

+ References

+ Details

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

- Definition

Amount of writeoff of financing receivable originated two years before current fiscal year. Excludes net investment in lease.

+ References

+ Details

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

- Definition

Amount of writeoff of financing receivable originated in fiscal year before current fiscal year. Excludes net investment in lease.

+ References

+ Details

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

- Definition

Amortized cost, before allowance for credit loss, of financing receivable. Excludes financing receivable covered under loss sharing agreement and net investment in lease.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 310
-SubTopic 10
-Name Accounting Standards Codification
-Section 45
-Paragraph 13
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481990/310-10-45-13

Reference 2: http://fasb.org/us-gaap/role/ref/otherTransitionRef
-Topic 310
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 7A
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481962/310-10-50-7A

Reference 3: http://fasb.org/us-gaap/role/ref/otherTransitionRef
-Topic 310
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 29
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481962/310-10-50-29

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Name Regulation S-K (SK)
-Number 229
-Section 1405
-Paragraph a
-Subparagraph (1)
-Publisher SEC

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Name Regulation S-K (SK)
-Number 229
-Section 1405
-Paragraph a
-Subparagraph (2)
-Publisher SEC

Reference 6: http://www.xbrl.org/2009/role/commonPracticeRef
-Name Regulation S-K (SK)
-Number 229
-Section 1404
-Paragraph a
-Publisher SEC

Reference 7: http://www.xbrl.org/2003/role/exampleRef
-Topic 326
-SubTopic 20
-Name Accounting Standards Codification
-Section 55
-Paragraph 80
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479294/326-20-55-80

Reference 8: http://www.xbrl.org/2003/role/exampleRef
-Topic 326
-SubTopic 20
-Name Accounting Standards Codification
-Section 55
-Paragraph 79
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479294/326-20-55-79

Reference 9: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 326
-SubTopic 20
-Name Accounting Standards Codification
-Section 45
-Paragraph 1
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479344/326-20-45-1

Reference 10: http://www.xbrl.org/2003/role/disclosureRef
-Topic 210
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(3)(b))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480566/210-10-S99-1

Reference 11: http://www.xbrl.org/2003/role/disclosureRef
-Topic 326
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 14
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479319/326-20-50-14

Reference 12: http://www.xbrl.org/2003/role/disclosureRef
-Topic 326
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 5
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479319/326-20-50-5

+ Details

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

- Details

Name:	us-gaap_FinancingReceivablePortfolioSegmentAxis=us-gaap_CommercialPortfolioSegmentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=us-gaap_CommercialRealEstateMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_InternalCreditAssessmentAxis=us-gaap_PassMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_InternalCreditAssessmentAxis=us-gaap_SpecialMentionMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_InternalCreditAssessmentAxis=us-gaap_SubstandardMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_InternalCreditAssessmentAxis=us-gaap_DoubtfulMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=trst_CommercialOtherReceivableMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancingReceivablePortfolioSegmentAxis=us-gaap_ResidentialMortgageMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=us-gaap_FirstMortgageMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancialInstrumentPerformanceStatusAxis=us-gaap_PerformingFinancingReceivableMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancialInstrumentPerformanceStatusAxis=us-gaap_NonperformingFinancingReceivableMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=us-gaap_HomeEquityLoanMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=us-gaap_HomeEquityMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancingReceivablePortfolioSegmentAxis=us-gaap_ConsumerLoanMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: