Income Taxes - Additional Information (Detail) (USD $)	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Income Tax Disclosure [Abstract]
Provision for income taxes	$ 7,267,000	$ 12,846,000	$ 19,838,000	$ 24,506,000
Effective tax rate	39.80%	40.40%	39.40%	39.80%
Provision for federal income taxes rate	32.70%	32.70%	32.70%	32.70%
Net benefit for state taxes rate	2.30%	2.30%	2.30%	2.30%
Provision for state taxes rate	6.60%	6.50%	6.60%	6.50%
Provision due to permanent book and tax difference	0.50%		0.10%
Provision of state and federal tax accounts		1.20%		0.60%
Income tax holiday, description			The Company's subsidiary in Costa Rica is operating under a 100% tax holiday through December 31, 2018 and a 50% tax holiday for the subsequent four years. The impact of the tax holiday in Costa Rica for the three and six months ended June 30, 2013 was immaterial.
Unrecognized tax benefit	15,400,000		15,400,000
Net tax benefit from unrecognized tax benefits, if recognized	14,500,000		14,500,000
Increase in gross unrecognized tax benefit	12,700,000		12,700,000
Undistributed earnings	$ 1,500,000		$ 3,200,000