Employee Benefit Plans - Additional Information (Detail) (USD $)	9 Months Ended	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2012 Provident Fund	Sep. 30, 2011 Provident Fund	Sep. 30, 2012 Provident Fund	Sep. 30, 2011 Provident Fund	Sep. 30, 2012 Gratuity Plan	Sep. 30, 2011 Gratuity Plan	Dec. 31, 2011 Gratuity Plan
Defined Benefit Plan Disclosure [Line Items]
Employee contribution percentage	60.00%
Employee contribution amount	$ 17,000
Contribution expense recognized by Indian entities		1,000,000	800,000	2,800,000	2,400,000	1,800,000	1,800,000
Accrued liability for retirement plan						$ 7,000,000		$ 5,600,000