Capital Stock - Additional Information (Detail) - $ / shares	Jan. 31, 2016	Jan. 31, 2015
Equity [Abstract]
Preference shares, shares authorized	20,000,000	20,000,000
Preference shares, par value	$ 0.00045	$ 0.00045
Preference shares, shares issued	0	0
Preference shares, shares outstanding	0	0
Ordinary shares, shares authorized	200,000,000	200,000,000