Segment Information - Additional Information (Detail)	3 Months Ended
	Mar. 31, 2012	Mar. 31, 2011
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 months ended March 31, 2012 and 2011.	No single customer accounted for more than 10% of the Company’s consolidated revenues during the three months ended March 31, 2012 and 2011.
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 months ended March 31, 2012.
UNITED KINGDOM
Segment Reporting Information [Line Items]
Percentage of revenues		Aggregate revenues attributable to customers in the United Kingdom accounted for 14.9% of the Company’s consolidated revenues during the three months ended March 31, 2011.