Note 4 - Income Taxes (Details Textual)	3 Months Ended
Mar. 31, 2015
Incremental US Tax if Earnings were Repatriated Percent	30.00%

Incremental U.S tax in percentage if the unremitted earnings of non-U.S. subsidiaries were repatriated.

No definition available.

Name:	glf_IncrementalUsTaxIfEarningsWereRepatriatedpercent
Namespace Prefix:	glf_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration