Income Taxes - Additional Information (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
Income Taxes [Line Items]
Provision for income taxes	$ 12,350	$ 7,187	$ 37,215	$ 12,322
Effective tax rate (as a percent)	38.00%	49.00%	42.00%	46.00%
Increase in deferred tax assets associated with changes in unrealized gain (loss) on marketable securities			126
Increase in deferred tax assets associated with changes in foreign currency translation adjustment gain (loss)			184
Unrecognized tax benefits	526		526
Unrecognized tax benefits that would affect the effective tax rate	474		474
Unrecognized tax benefits interest and penalties	17		149
Unrecognized tax benefits accrued interest and penalties	148		148
Pan [Member]
Income Taxes [Line Items]
Deferred tax assets	$ 1,500		$ 1,500
Deferred tax assets, valuation allowance (as a percent)	100.00%		100.00%