Accrued Expenses (Schedule Of Accrued Expenses) (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Accrued Liabilities [Abstract]
Vacation	$ 7,266us-gaap_AccruedVacationCurrent	$ 7,077us-gaap_AccruedVacationCurrent
Payrolls, related taxes and medical and other benefits	4,119	5,679
Incentive compensation	3,803us-gaap_AccruedBonusesCurrent	4,148us-gaap_AccruedBonusesCurrent
Workers’ compensation and disabilities	3,007	2,753
Accrued Utilities, Current	2,186us-gaap_AccruedUtilitiesCurrent	2,494us-gaap_AccruedUtilitiesCurrent
Contractual indemnification claims	0	2,604
Taxes other than federal income and payroll	841	2,153
Other	10,827us-gaap_OtherAccruedLiabilitiesCurrent	15,250us-gaap_OtherAccruedLiabilitiesCurrent
Total	$ 32,049us-gaap_AccruedLiabilitiesCurrent	$ 42,158us-gaap_AccruedLiabilitiesCurrent

Accrued contractual indemnification claims

No definition available.

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Data Type:	xbrli:monetaryItemType
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Period Type:	instant

- Definition

Carrying value as of the balance sheet date of obligations incurred and payable for, including but not limited to, real and property taxes, VAT taxes, franchise taxes and other taxes other than income and payroll taxes. Used to reflect the current portion of the liabilities (due within one year or within the normal operating cycle if longer).

+ References

No definition available.

+ Details

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Namespace Prefix:	tg_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Carrying value as of the balance sheet date of obligations incurred and payable for incentive compensation awarded to employees and directors or earned by them based on the terms of one or more relevant arrangements. Used to reflect the current portion of the liabilities (due within one year or within the normal operating cycle if longer).

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 20

-Article 5

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Glossary Current Liabilities

-URI http://asc.fasb.org/extlink&oid=6509677

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section 45

-Paragraph 8

-URI http://asc.fasb.org/extlink&oid=28358313&loc=d3e6935-107765

Reference 4: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.20)

-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 5: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section 45

-Paragraph 6

-URI http://asc.fasb.org/extlink&oid=28358313&loc=d3e6911-107765

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Carrying value as of the balance sheet date of obligations incurred and payable, pertaining to costs that are statutory in nature, are incurred on contractual obligations, or accumulate over time and for which invoices have not yet been received or will not be rendered. Examples include taxes, interest, rent and utilities. Used to reflect the current portion of the liabilities (due within one year or within the normal operating cycle if longer).

+ References

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Details

Name:	us-gaap_AccruedLiabilitiesCurrentAndNoncurrentAbstract
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Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Carrying value as of the balance sheet date of obligations incurred through that date and payable for utilities, such as electrical power, heating oil, natural gas, and water. Used to reflect the current portion of the liabilities (due within one year or within the normal operating cycle if longer).

+ References

+ Details

Name:	us-gaap_AccruedUtilitiesCurrent
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Carrying value as of the balance sheet date of obligations incurred and payable for unused vacation time owed to employees based on the entity's vacation benefit given to its employees. Used to reflect the current portion of the liabilities (due within one year or within the normal operating cycle if longer).

+ References

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Total of the carrying values as of the balance sheet date of obligations incurred through that date and payable for obligations related to services received from employees, such as accrued salaries and bonuses, payroll taxes and fringe benefits. Used to reflect the current portion of the liabilities (due within one year or within the normal operating cycle if longer).

+ References

+ Details

Name:	us-gaap_EmployeeRelatedLiabilitiesCurrent
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Carrying value as of the balance sheet date of obligations incurred through that date and payable arising from transactions not otherwise specified in the taxonomy. Used to reflect the current portion of the liabilities (due within one year or within the normal operating cycle if longer).

+ References

+ Details

Name:	us-gaap_OtherAccruedLiabilitiesCurrent
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Carrying value as of the balance sheet date of obligations and payables pertaining to claims incurred of a workers compensation nature. Used to reflect the current portion of the liabilities (due within one year or within the normal operating cycle if longer).

+ References

+ Details

Name:	us-gaap_WorkersCompensationLiabilityCurrent
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant