Investments in Foreign Joint Ventures - Summary of Financial Information of Foreign Joint Ventures (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012	Dec. 31, 2012
BOMAY [Member]
Assets:
Total current assets	$ 100,829		$ 100,829		$ 87,127
Total non-current assets	5,122		5,122		5,025
Total assets	105,951		105,951		92,152
Liabilities and equity:
Total liabilities	79,312		79,312		69,154
Total equity	26,639		26,639		22,998
Total liabilities and equity	105,951		105,951		95,152
Revenue	17,995	20,069	82,986	77,078
Gross profit	2,853	3,452	10,451	11,948
Earnings	1,187	1,561	5,308	5,962
MIEFE [Member]
Assets:
Total current assets	4,200		4,200		3,726
Total non-current assets	135		135		120
Total assets	4,335		4,335		3,846
Liabilities and equity:
Total liabilities	1,460		1,460		1,257
Total equity	2,875		2,875		2,589
Total liabilities and equity	4,335		4,335		3,846
Revenue	1,530	743	7,021	5,823
Gross profit	372	441	1,659	1,185
Earnings	(29)		356	46
AAG [Member]
Assets:
Total current assets	3,109		3,109		1,983
Total non-current assets	1,595		1,595		347
Total assets	4,704		4,704		2,330
Liabilities and equity:
Total liabilities	1,728		1,728		1,474
Total equity	2,976		2,976		856
Total liabilities and equity	4,704		4,704		2,330
Revenue	1,434	2,275	9,433	4,940
Gross profit	259	842	3,691	1,715
Earnings	$ (59)	$ 329	$ 1,777	$ 419