Redeemable Noncontrolling Interests - Additional Information (Detail) (USD $)	3 Months Ended
Mar. 31, 2013
Noncontrolling Interest [Line Items]
Adjusted redeemable non-controlling interest	$ (5,701,000)
Central American joint venture [Member]
Noncontrolling Interest [Line Items]
Acquired additional interest	10.00%
Acquired additional interest value	6,000,000
Ownership interest after acquisition	100.00%
Central American joint venture [Member] \| Additional Paid-In Capital [Member]
Noncontrolling Interest [Line Items]
Adjusted redeemable non-controlling interest	$ 5,700,000

The cash outflow associated with the purchase of noncontrolling interest during the period.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 230

-SubTopic 10

-Section 45

-Paragraph 13

-Subparagraph (b)

-URI http://asc.fasb.org/extlink&oid=6943989&loc=d3e3213-108585

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 95

-Paragraph 17

-Subparagraph b

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Name:	us-gaap_PaymentsToAcquireAdditionalInterestInSubsidiaries
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration