Share-Based Payments, Deferred Compensation and Employee Ownership Plans - Restricted Shares and Other Share Based Payments Narrative (Details) - Equity Plans - Restricted Stock Units (RSUs) - shares	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Dec. 31, 2020
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Non-Option Equity Instruments, Outstanding, Number			334,230
Non-employee Director
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted, shares	0	0
Share-based Compensation Arrangement by Share-based Payment Award, Non-Option Equity Instruments, Other	0	0
Share-based Compensation Arrangement by Share-based Payment Award, Non-Option Equity Instruments, Outstanding, Number	259,536		259,536