Taxation - Reconciliation of Earnings before Income Taxes Computed by Applying Effective Rate (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Income Tax Disclosure [Abstract]
Earnings before income tax	$ 40,688	$ 20,829
Expected tax rate	0.00%	0.00%
Foreign taxes at local expected rates	17.30%	33.50%
Change in uncertain tax positions	(5.50%)	(11.40%)
Change in valuation allowance	5.70%	15.30%
Other	0.40%	0.30%
Effective tax rate	17.90%	37.70%