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		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 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	90,465	0	90,465
Share-based Compensation Arrangement by Share-based Payment Award, Non-Option Equity Instruments, Other	27,047	48,021	41,667	48,021
Share-based Compensation Arrangement by Share-based Payment Award, Non-Option Equity Instruments, Outstanding, Number	217,869		217,869		259,536