Net income (loss) Per Share - Calculation of Basic and Diluted Net Income or Loss Per Share (Detail) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Numerator:
Net income (loss)	$ 1,290	$ (11,302)	$ 19,142	$ (20,253)
Denominator
Weighted-average ordinary shares outstanding (in shares)	21,959	17,679	21,922	17,679
Dilutive stock options outstanding (in shares)	939	0	1,005	0
Net weighted average ordinary shares outstanding (in shares)	22,898	17,679	22,927	17,679
Net income (loss) per share attributable to holders of ordinary shares
Basic (in dollars per share)	$ 0.06	$ (0.64)	$ 0.87	$ (1.15)
Diluted (in dollars per share)	$ 0.06	$ (0.64)	$ 0.83	$ (1.15)