Stock Based Compensation - Nonvested Stock Options Activity (Details) (Stock Options, USD $) In Thousands, except Per Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Stock Options
Share-based Compensation Arrangement By Share-based Payment Award, Options, Nonvested, Number Of Shares [Roll Forward]
Nonvested options outstanding at beginning of year (shares)	2,307	2,102	2,125
Nonvested options granted (shares)	5,164	2,288	1,599
Options vested (shares)	(2,658)	(1,988)	(1,491)
Nonvested options forfeited, canceled and expired (shares)	(396)	(95)	(131)
Nonvested options outstanding at end of year (shares)	4,417	2,307	2,102
Share-based Compensation Arrangement By Share-based Payment Award, Options, Nonvested, Weighted Average Grant Date Fair Value [Roll Forward]
Weighted average grant date fair value - nonvested options outstanding at beginning of year (Cdn$ per share)	$ 1.91	$ 1.90	$ 1.49
Weighted average grant date fair value - nonvested option granted (Cdn$ per share)	$ 1.21	$ 1.78	$ 2.54
Weighted average grant date fair value - options vested (Cdn$ per share)	$ 1.43	$ 1.81	$ 1.94
Weighted average grant date fair value - nonvested options fofeited, canceled and expired (Cdn$ per share)	$ 1.65	$ 2.14	$ 1.73
Weighted average grant date fair value - nonvested options outstanding at end of year (Cdn$ per share)	$ 1.4	$ 1.91	$ 1.90