XML 56 R36.htm IDEA: XBRL DOCUMENT v3.20.1
Letters of Credit (Details) - USD ($)
$ in Millions
Mar. 31, 2020
Dec. 31, 2019
Line of Credit Facility [Line Items]    
Amount outstanding at period end $ 0.0 $ 30.0
Letter of Credit    
Line of Credit Facility [Line Items]    
Amount outstanding at period end $ 10.0 $ 10.0