Distributions - Tax Characteristics of Distributions (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Distributions [Abstract]
Common Share Distributions Payments of Ordinary Dividends	$ 0.36	$ 0.41	$ 0.52
Common Share Distributions Capital Gain	0.14	0.02	0
Common Share Distributions Non-taxable Distributions	0.10	0.17	0.08
Common Stock, Dividends, Per Share, Declared	$ 0.60	$ 0.60	$ 0.60
Percentage Of Distributions classified as ordinary income	59.10%	69.00%	87.00%
Percentage Of Distributions classified as capital gain	23.50%	3.30%	0.00%
Percentage Of Distributions classified as non-taxable distribution	17.40%	27.70%	13.00%
Dividends, Preferred Stock	$ 6,900	$ 6,900	$ 6,900
Percentage Of Preferred Distributions classified as ordinary income	100.00%	100.00%	100.00%