Summary of Significant Accounting Policies - Schedule of Options to Purchase Common Shares and Restricted Stock Units (Detail) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total options and restricted stock units	121	4,081	865	4,081
Options to Purchase Common Shares [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total options and restricted stock units	50	2,947	457	2,947
Restricted Stock Units [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total options and restricted stock units	71	1,134	408	1,134