XML 122 R101.htm IDEA: XBRL DOCUMENT v3.3.1.900

Commitments and contingencies - Matters relating to the St. Croix Alumina Refining Facility (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2015 USD ($)
Accrual for Environmental Loss Contingencies [Abstract]
Environmental remediation expense for Hydrocarbon Recovery Plan	$ 1,085

X

- References

No definition available.

+ Details

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

X

- Definition

The charge against earnings in the period for known or estimated future costs arising from requirements to perform environmental remediation activities.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 410
-SubTopic 30
-Section 50
-Paragraph 12
-URI http://asc.fasb.org/extlink&oid=6393242&loc=d3e13296-110859

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 28
-URI http://asc.fasb.org/extlink&oid=56944662&loc=d3e3602-108585

+ Details

Name:	us-gaap_EnvironmentalRemediationExpense
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration