Income Taxes (Details) - USD ($) $ in Thousands	1 Months Ended	3 Months Ended		6 Months Ended
	Mar. 31, 2013	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Income Taxes [Abstract]
Income tax expense		$ 0	$ 1	$ 1	$ 2
Paid federal income taxes attributable to alternative minimum tax rate	$ 501