XML 23 R70.htm IDEA: XBRL DOCUMENT v2.4.0.8

Supplementary Balance Sheet Detail (Narrative) (Details) (USD $) In Millions, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Balance Sheet Related Disclosures [Abstract]
Cost in excess of normal absorption	$ 0	$ 3.5

X

- Definition

Inventory costs excess of normal absorption.

+ References

No definition available.

+ Details

Name:	gti_InventoryCostsExcessOfNormalAbsorption
Namespace Prefix:	gti_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

X

- Details

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