Commitments and Contingencies (Tables)

12 Months Ended

Dec. 31, 2012

Commitments and Contingencies Disclosure [Abstract]

Summary of Changes in Asset Retirement Obligations

The following table summarizes the changes in this liability from December 31, 2009 through December 31, 2012 (in thousands):

Balance at December 31, 2009	$	28,996
Accretion	3,523
Payments made	(1,144		)
Currency translation adjustments	1,509
Balance at December 31, 2010	32,884
Accretion	4,114
Payments made	(341		)
Currency translation adjustments	(771		)
Balance at December 31, 2011	35,886
Accretion	4,554
Payments made	(1,169		)
Currency translation adjustments	834
Balance at December 31, 2012	$	40,105

Schedule of Future Minimum Lease Payments

Future minimum payments required under operating leases that have initial or remaining non-cancellable lease terms in excess of one year at December 31, 2012 are as follows (in thousands):

	Operating Leases
For year ending:
December 31, 2013	$	3,882
December 31, 2014	3,170
December 31, 2015	2,312
December 31, 2016	5,119
December 31, 2017	4,723
Thereafter	419
Total future minimum lease payments	$	19,625

Summary of Purchase and Sale Commitments

At December 31, 2012, such commitments included the following (in thousands):

	At December 31, 2012
	Volume (barrels)	Value ($)
Fixed price purchases	169	14,630
Fixed price sales	169	14,927
Floating price purchases	22,339	2,108,387
Floating price sales	22,536	2,119,455