Indonesia - Additional Information (Detail) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2013 acre	Dec. 31, 2012	Jan. 31, 2011	Jan. 14, 2011	Sep. 15, 2010	Dec. 31, 2007
Projects with Exploratory Well Costs Capitalized for More than One Year [Line Items]
Farmout agreement to acquire interest	7.10%
Extended period of initial exploration phase	4 years
Number of wells under operational activities	2
Budong PSC [Member]
Projects with Exploratory Well Costs Capitalized for More than One Year [Line Items]
Farmout agreement to acquire interest			64.40%		54.40%	47.00%
Committing to fund the fist phase cap						$ 17.2
Maximum level of carried interest						20.0
Increase in funding obligation due to option exercise					2.7
Cost of funding to acquire interest in acquiree					19.9
Acquire additional equity, first acquisition					7.40%
Acquire additional equity, second acquisition				10.00%
Cost of additional interest acquisition				3.7
Period available related to acquisition cost payable	10 days
Cost sharing interest			64.51%
Expiration date of contract	Jan. 15, 2013	Jan. 16, 2013
Extended period of initial exploration phase	4 years
Initial exploration phase	6 years
Acquired additional participating interest, third acquisition		7.10%
Participating ownership interest		71.50%
Participating ownership interest until first commercial production		72.00%
Percentage funded consideration for transaction		100.00%
Duration exploration not drilled		18 months
Consideration paid		3.2
Area covered during initial exploration period	1.35
Exploration period	10 years
Development phase period	20 years
Initial exploration phase	3 years
Original area relinquished to SKK Migas	45.00%
Original area relinquished	35.00%
Relinquishment deferred	10.00%
Budong PSC covered	750,000
Current percentage of original contract area	55.00%
Reduced percentage of original contract area	20.00%
Area remained covered under initial contract	300,000
Impaired expense	0.6
Oil and gas properties	4.6	5.3
Valuation allowance expect to recover	$ 2.8
Budong PSC [Member] | Lariang Basin [Member]
Projects with Exploratory Well Costs Capitalized for More than One Year [Line Items]
Number of leads used while remapping of Basin	8
Budong PSC [Member] | Karama Basin [Member]
Projects with Exploratory Well Costs Capitalized for More than One Year [Line Items]
Number of leads used while remapping of Basin	5