Distributions - Tax Characteristics of Distributions (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Distributions [Abstract]
Common Share Distributions Payments of Ordinary Dividends	$ 0.55	$ 0.38	$ 0
Common Share Distributions Capital Gain	0	0.26	0.62
Common Share Distributions Non-taxable Distributions	0.17	0	0
Common Stock, Dividends, Per Share, Paid	$ 0.72	$ 0.64	$ 0.62
Percentage Of Distributions classified as ordinary income	76.20%	60.00%	0.00%
Percentage Of Distributions classified as capital gain	0.00%	40.00%	100.00%
Percentage Of Distributions classified as non-taxable distribution	23.80%	0.00%	0.00%
Dividends, Preferred Stock	$ 0	$ 2,032	$ 6,900
Percentage Of Preferred Distributions classified as ordinary income	0.00%	60.00%	0.00%
Percentage Of Preferred Distributions classified as capital gain	0.00%	40.00%	100.00%
Percentage Of Preferred Distributions classified as non-taxable distribution	0.00%	0.00%	0.00%