Class of Warrant or Right, Number of Rights Attached to Each Outstanding Share of Common Stock

No definition available.

Name:	tg_ClassofWarrantorRightNumberofRightsAttachedtoEachOutstandingShareofCommonStock
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Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant

Exercise Price of Participating Cumulative Preferred Stock, Per Share

No definition available.

Name:	tg_ExercisePriceOfParticipatingCumulativePreferredStockPerShare
Namespace Prefix:	tg_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

Percentage of common stock ownership required in a tender offer for exercise of rights.

No definition available.

Name:	tg_PercentageOfCommonStockOwnershipRequiredInTenderOfferForExerciseOfRights
Namespace Prefix:	tg_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

Percentage of outstanding common stock shares to be acquired for exercise of rights.

No definition available.

Name:	tg_PercentageOfOutstandingCommonStockSharesToBeAcquiredForExerciseOfRights
Namespace Prefix:	tg_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

Portion of shares each Right can buy

No definition available.

Name:	tg_PortionOfSharesEachRightCanBuy
Namespace Prefix:	tg_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

Share-Based Compensation Arrangement by Share-based Payment Award, Price Per RIght Redeemed by Board of DIrectors in Event Agreement is Not Approved

No definition available.

Name:	tg_ShareBasedCompensationArrangementbySharebasedPaymentAwardPricePerRIghtRedeemedbyBoardofDIrectorsinEventAgreementisNotApproved
Namespace Prefix:	tg_
Data Type:	num:perShareItemType
Balance Type:	na
Period Type:	duration

Amount paid to shareholders to redeem shareholder rights per Shareholder Rights Agreement.

No definition available.

Name:	tg_ShareholderRightsRedemptionPayment
Namespace Prefix:	tg_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

No definition available.

Name:	us-gaap_WarrantsAndRightsNoteDisclosureAbstract
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

Shareholder Rights Agreement (Details) - USD ($)		3 Months Ended		6 Months Ended
Shareholder Rights Agreement (Details) - USD ($)	Feb. 19, 2014	Jun. 30, 2015	Mar. 31, 2014	Jun. 30, 2014	Nov. 18, 2013
Warrants and Rights Note Disclosure [Abstract]
Number of rights attached to each outstanding share of common stock					1
Portion of shares each Right can buy			0.01
Exercise price of participating cumulative preferred stock, per share		$ 150
Percentage of outstanding common stock shares to be acquired for exercise of rights		20.00%
Percentage of common stock ownership required in a tender offer for exercise of rights		20.00%
Price per rIght redeemed by board of dIrectors in event agreement is not approved	$ 0.01
Shareholder Rights Redemption Payment				$ 300,000