Common Stock Incentive Plan - Restricted Stock (Details) - Restricted Stock $ in Millions	6 Months Ended
	Jun. 30, 2020 USD ($) shares
Common Stock Incentive Plan
Shares granted in period (in shares)	100,473
Vesting period (in years)	4 years
Unamortized share-based compensation expense | $	$ 11.5
Independent Directors
Common Stock Incentive Plan
Shares granted in period (in shares)	36,000
Independent Directors | Vest immediately
Common Stock Incentive Plan
Shares granted in period (in shares)	24,000
Independent Directors | Three-year vesting
Common Stock Incentive Plan
Shares granted in period (in shares)	12,000
Vesting period (in years)	3 years
Former CFO | Vest immediately
Common Stock Incentive Plan
Shares granted in period (in shares)	4,541