XML 35 R13.htm IDEA: XBRL DOCUMENT
v3.3.1.900

Energy and Related Sales, Net | 12 Months Ended
--- | ---
Dec. 31, 2015
Text Block [Abstract] |
Energy and Related Sales, Net |
4. | ENERGY AND RELATED SALES, NET
We sell excess power generated by the Spring Grove, PA facility. We also sell renewable energy credits generated by the Spring Grove, PA and Chillicothe, OH facilities representing sales of certified credits earned related to burning renewable sources of energy such as black liquor and wood waste. The following table summarizes this activity for each of the past three years:
|  | Year ended December 31 |
In thousands |  |  | 2015 |  |  |  | 2014 |  |  |  | 2013 |
Energy sales |  | $ | 5,315 |  |  | $ | 11,886 |  |  | $ | 8,189 |
Costs to produce |  |  | (4,428 | ) |  |  | (6,204 | ) |  |  | (6,784 | )
Net |  |  | 887 |  |  |  | 5,682 |  |  |  | 1,405 |
Renewable energy credits |  |  | 4,777 |  |  |  | 2,245 |  |  |  | 1,748 |
Total |  | $ | 5,664 |  |  | $ | 7,927 |  |  | $ | 3,153 |

X
- Definition The entire disclosure of revenues and expenses directly related to the sales of power generated by the Company not otherwise consumed in operations. + References No definition available. + Details
Name: | glt_EnergyAndRelatedSalesNetDisclosureTextBlock
Namespace Prefix: | glt_
Data Type: | nonnum:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- References No definition available. + Details
Name: | us-gaap_TextBlockAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration