Stock Option Plans - Stock Option Activity (Details) In Thousands, except Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2014 USD ($)	Dec. 31, 2014 CAD	Dec. 31, 2013 USD ($)	Dec. 31, 2013 CAD	Dec. 31, 2012 USD ($)	Dec. 31, 2012 CAD	Dec. 31, 2011 USD ($)	Dec. 31, 2011 CAD
Stock Option Activity [Abstract]
Number of Options Outstanding, Beginning balance	1,333,099	1,333,099	1,128,437	1,128,437	1,059,510	1,059,510
Number of Options, Granted	205,170	205,170	292,418	292,418	150,102	150,102
Number of Options, Exercised	(2,417)	(2,417)	(8,329)	(8,329)
Number of Options, Forfeited and expired	(51,634)	(51,634)	(79,427)	(79,427)	(81,175)	(81,175)
Number of Options Outstanding, Ending balance	1,484,218	1,484,218	1,333,099	1,333,099	1,128,437	1,128,437	1,059,510	1,059,510
Number of Options Exercisable, Ending balance	1,116,564	1,116,564
Weighted Average Exercise Price Outstanding, Beginning balance	$ 3.88	3.98	$ 4.17	4.13	$ 4.22	4.27
Weighted Average Exercise Price, Granted	$ 9.35	10.84	$ 3.64	3.74	$ 3.64	3.64
Weighted Average Exercise Price, Exercised	$ 5.23	6.07	$ 5.88	6.07
Weighted Average Exercise Price, Forfeited and expired	$ 5.14	5.96	$ 4.76	4.90	$ 5.24	5.24
Weighted Average Exercise Price Outstanding, Ending balance	$ 4.20	4.88	$ 3.88	3.98	$ 4.17	4.13	$ 4.22	4.27
Weighted Average Exercise Price, Exercisable Ending balance	$ 3.44	3.99
Weighted Average Remaining Contractual Life In Years, Outstanding	5 years 8 months 12 days	5 years 8 months 12 days	5 years 9 months 18 days	5 years 9 months 18 days	5 years 9 months 22 days	5 years 9 months 22 days	6 years 26 days	6 years 26 days
Weighted Average Remaining Contractual Life In Years, Exercisable	4 years 8 months 23 days	4 years 8 months 23 days
Aggregate Intrinsic Value, Exercised	$ 23		$ 37
Aggregate Intrinsic Value, Outstanding, Ending balance	15,551		8,300
Aggregate Intrinsic Value, Exercisable, Ending balance	$ 12,554