XML 136 R63.htm IDEA: XBRL DOCUMENT v2.4.1.9

Accounting Policies - Schedule of Range of Estimated Service Lives (Detail)	12 Months Ended
	Dec. 31, 2014
Minimum [Member]
Property Plant And Equipment Useful Life [Abstract]
Range of estimated service lives	5 years
Maximum [Member]
Property Plant And Equipment Useful Life [Abstract]
Range of estimated service lives	30 years
Buildings [Member] | Minimum [Member]
Property Plant And Equipment Useful Life [Abstract]
Range of estimated service lives	15 years
Buildings [Member] | Maximum [Member]
Property Plant And Equipment Useful Life [Abstract]
Range of estimated service lives	45 years
Machinery and Equipment [Member] | Minimum [Member]
Property Plant And Equipment Useful Life [Abstract]
Range of estimated service lives	5 years
Machinery and Equipment [Member] | Maximum [Member]
Property Plant And Equipment Useful Life [Abstract]
Range of estimated service lives	40 years
Other [Member] | Minimum [Member]
Property Plant And Equipment Useful Life [Abstract]
Range of estimated service lives	3 years
Other [Member] | Maximum [Member]
Property Plant And Equipment Useful Life [Abstract]
Range of estimated service lives	25 years

X

- Details

Name:	glt_PropertyPlantAndEquipmentUsefulLifeAbstract
Namespace Prefix:	glt_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

X

- Definition

Useful life of long lived, physical assets used in the normal conduct of business and not intended for resale, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. Examples include, but not limited to, land, buildings, machinery and equipment, office equipment, furniture and fixtures, and computer equipment.

+ References

No definition available.

+ Details

Name:	us-gaap_PropertyPlantAndEquipmentUsefulLife
Namespace Prefix:	us-gaap_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

X

- Details

Name:	us-gaap_PropertyPlantAndEquipmentByTypeAxis=us-gaap_BuildingMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_PropertyPlantAndEquipmentByTypeAxis=us-gaap_MachineryAndEquipmentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_PropertyPlantAndEquipmentByTypeAxis=us-gaap_OtherCapitalizedPropertyPlantAndEquipmentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_RangeAxis=us-gaap_MaximumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_RangeAxis=us-gaap_MinimumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: