XML 64 R42.htm IDEA: XBRL DOCUMENT v3.20.4
Summary of Significant Accounting Policies - Per Common Share and Segment (Details)
12 Months Ended
Dec. 31, 2020
segment
$ / shares
Dec. 31, 2019
$ / shares
Accounting Policies [Abstract]    
Common shares, par value (in dollars per share) | $ / shares $ 0.01 $ 0.01
Number of operating segments | segment 2