Segment Reporting - Additional Information (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended
Mar. 31, 2013 Segment Customer
Segment Reporting Information [Line Items]
Number of contracts or customers accounted for more than 10% of the Company's total revenues at the consolidated or reportable segment level	0
Number of geographic operating segments	3
Accumulated impairment losses associated with goodwill	$ 0

The accumulated impairment losses related to goodwill as of the balance sheet date.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 350

-SubTopic 20

-Section 50

-Paragraph 1

-Subparagraph (a,h)

-URI http://asc.fasb.org/extlink&oid=14024403&loc=d3e13816-109267

Name:	us-gaap_GoodwillImpairedAccumulatedImpairmentLoss
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant