Common Shares (Detail)	Dec. 31, 2013	Dec. 31, 2012
Common Stock, Shares, Issued	22,701,613	22,111,675
Common Stock, Shares, Outstanding	22,592,956	22,102,549
Reserved For Issuance Upon Exercise Or Vesting Of Equity Awards
Common Stock, Capital Shares Reserved for Future Issuance	2,460,516	2,666,024
Stock options | Reserved For Issuance Upon Exercise Or Vesting Of Equity Awards
Common Stock, Capital Shares Reserved for Future Issuance	1,678,500	1,833,500
Nil Coupon Perpetual Loan Notes
Common Stock, Capital Shares Reserved for Future Issuance	6,715	6,715