Significant Accounting Policies - Foreign Currency Translations (Details)	Jul. 31, 2016 AUD / $	Jul. 31, 2016 NOK / $	Jul. 31, 2016 € / $	Jul. 31, 2016 CAD / $	Jul. 31, 2016 £ / $	Jul. 31, 2015 AUD / $	Jul. 31, 2015 NOK / $	Jul. 31, 2015 € / $	Jul. 31, 2015 CAD / $	Jul. 31, 2015 £ / $
Average rates
Multiple foreign currency exchange rates
Foreign currency exchange rates translations	0.741358	0.119985	1.119985	0.771605	1.396682	0.765316	0.127480	1.111956	0.801231	1.552814
Period end rates
Multiple foreign currency exchange rates
Foreign currency exchange rates translations	0.759758	0.118703	1.116939	0.766812	1.326969	0.733119	0.122863	1.102782	0.766460	1.563271