Segment Information - Additional Information (Detail)	3 Months Ended		9 Months Ended
	Sep. 30, 2011	Sep. 30, 2010	Sep. 30, 2011	Sep. 30, 2010
Customer Concentration Risk
Segment Reporting Information [Line Items]
Percentage of revenues	No single customer accounted for more than 10% of the Company's consolidated revenues during the three and nine months ended September 30, 2011.	No single customer accounted for more than 10% of the Company's consolidated revenues during the three and nine months ended September 30, 2010.	No single customer accounted for more than 10% of the Company's consolidated revenues during the three and nine months ended September 30, 2011.	No single customer accounted for more than 10% of the Company's consolidated revenues during the three and nine months ended September 30, 2010.
Geographic Concentration Risk
Segment Reporting Information [Line Items]
Percentage of revenues		No other country outside the United States accounted for more than 10% of the Company's consolidated revenues during the three and nine months ended September 30, 2010.		No other country outside the United States accounted for more than 10% of the Company's consolidated revenues during the three and nine months ended September 30, 2010.
UNITED KINGDOM
Segment Reporting Information [Line Items]
Percentage of aggregate revenue attributable to customers			10.10%