Stock-based Compensation (Narrative) (Details) - shares	Feb. 29, 2020	Jan. 14, 2020	May 31, 2019	Feb. 28, 2019	May 28, 2010
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common Stock, Shares Authorized	2,000,000,000	2,000,000,000	2,000,000,000	500,000,000
2010 Stock Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common Stock, Shares Authorized					10,294,500
2010 Stock Plan - Stock Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common Stock, Shares Authorized					5,147,250
2010 Stock Plan - Restricted Shares [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common Stock, Shares Authorized					5,147,250