Accounts Receivable (Tables)

12 Months Ended

Dec. 31, 2011

Accounts Receivables [Abstract]

Components of accounts receivable

	As of December 31,
	2011		2010
Other co-venturers	$	8,890	$	6,769
Trade		91,959		75,653
Insurance receivable		4,236		1,718
Unbilled accounts receivable		13,009		4,352
Other		45		37
	$	118,139	$	88,529