Other Assets - Investments - Equity Securities (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020	Dec. 31, 2020
Equity Securities
Investments - equity securities	$ 339		$ 339		$ 2,623
Unrealized loss on investments held as of balance sheet date	500	$ 100	1,100	$ 4,800
Preferred stock
Equity Securities
Investments - equity securities	$ 300		$ 300		$ 2,600