For an entity that discloses a concentration risk in relation to quantitative amount, which serves as the "benchmark" (or denominator) in the equation, this concept represents the concentration percentage derived from the division.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 825

-SubTopic 10

-Section 50

-Paragraph 21

-Subparagraph (a)

-URI http://asc.fasb.org/extlink&oid=28364263&loc=d3e13537-108611

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 275

-SubTopic 10

-Section 50

-Paragraph 20

-URI http://asc.fasb.org/extlink&oid=6927468&loc=d3e6404-108592

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 825

-SubTopic 10

-Section 50

-Paragraph 20

-URI http://asc.fasb.org/extlink&oid=28364263&loc=d3e13531-108611

Reference 4: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 275

-SubTopic 10

-Section 50

-Paragraph 18

-URI http://asc.fasb.org/extlink&oid=6927468&loc=d3e6351-108592

Name:	us-gaap_ConcentrationRiskPercentage1
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

Significant Customers - Additional Information (Detail)	3 Months Ended		9 Months Ended
Significant Customers - Additional Information (Detail)	Sep. 30, 2013 Customer	Sep. 30, 2012 Customer	Sep. 30, 2013 Customer	Sep. 30, 2012 Customer	Dec. 31, 2012
Revenue, Major Customer [Line Items]
Number of significant customer	3	2	2	2
Trade receivables	10.00%		10.00%
Accounts receivable	74.00%		74.00%		93.00%
Customer One [Member]
Revenue, Major Customer [Line Items]
Revenue	23.00%	44.00%	35.00%	44.00%
Customer Two [Member]
Revenue, Major Customer [Line Items]
Revenue	17.00%	35.00%	13.00%	20.00%
Customer Three [Member]
Revenue, Major Customer [Line Items]
Revenue	10.00%