Investments - Equity Securities (Details) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Equity Securities
Investments - equity securities		$ 2,623	$ 9,746
Unrealized loss on investments, net		(4,688)	(5,342)	$ (3,035)
Reclassification into retained earnings	[1]			$ 932
Preferred stock
Equity Securities
Investments - equity securities		$ 2,600	$ 9,700

[1] The reclassification into retained earnings for the year ended December 31, 2018 relates to the adoption of ASU 2016-01 Financial Instruments – Overall, as amended (“ASU 2016-01”). The new guidance was effective January 1, 2018, and required equity investments to be measured at fair value with changes in fair value recognized in results of operations rather than the consolidated statements of comprehensive income.