XML 90 R63.htm IDEA: XBRL DOCUMENT v3.20.1
Debt and Credit Arrangements - Fair Value Disclosures about Debt (Details)
Mar. 31, 2020
Dec. 31, 2019
Convertible Debt | Convertible Notes, due 2024    
Debt Instrument    
Debt instrument percentage over par value 78.00% 132.00%