Deferred Revenue - Additional Information (Detail) (USD $) In Thousands, unless otherwise specified	0 Months Ended	12 Months Ended
Sep. 22, 2013	Dec. 31, 2011
Revenue Recognition [Abstract]
Received rent payment	$ 3,293
Term of oil exploration lease	8 years	8 years
Lease period where payment recognized	12 months

The cash inflow associated with the collection of receivables arising from the lease of real estate, equipment or other fixed assets for a specified time in exchange for payment, usually in the form of rent; excludes proceeds from sales-type lease transactions, which are classified as operating activities.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Glossary Investing Activities

-URI http://asc.fasb.org/extlink&oid=6516133

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 230

-SubTopic 10

-Section 45

-Paragraph 12

-Subparagraph (e)

-URI http://asc.fasb.org/extlink&oid=31042434&loc=d3e3179-108585

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