Stock-Based Compensation - Narrative (Details) $ in Millions	3 Months Ended	123 Months Ended
	Mar. 31, 2021 USD ($) shares	Mar. 31, 2021 USD ($) shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted (in shares)		0
Restricted Shares and Performance Based Shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized expense related to stock awards | $	$ 6.7	$ 6.7
Period of time stock expense is expected to be recognized	2 years 1 month 6 days
Executive | Performance Shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Maximum number of shares awarded in year one (in shares)	142,080	142,080
Maximum number of shares awarded in year two (in shares)	142,047	142,047
Maximum number of shares awarded in year three (in shares)	152,414	152,414
Performance period	3 years
Executive | Performance Shares | Achieved performance target for 2017 through 2019
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Maximum number of shares awarded in year one (in shares)	124,941	124,941
Performance Equity Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period	3 years
Vesting rate	100.00%
Performance Equity Plan | Non-employee Members of the Board of Directors
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period	1 year