Equity (Deficit) and Earnings (Loss) per Share - Changes in Total Equity (Deficit) (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014
Changes in Total Equity (Deficit):
Balance at beginning of period				$ (105,905)					$ (105,905)
Net income (loss)	$ (3,830)	$ (3,076)	$ (4,029)	(3,329)	$ (4,094)	$ (4,435)	$ (5,128)	$ (3,695)	(14,264)	$ (17,352)
Dividends and distributions									(4,021)
Balance at end of period	(124,190)				(105,905)				(124,190)	(105,905)
Total Equity (Deficit)
Changes in Total Equity (Deficit):
Balance at beginning of period				(149,140)				(144,471)	(149,140)	(144,471)
Net income (loss)									(2,246)
Dividends and distributions									(1,748)
Balance at end of period	(153,134)				(149,140)				(153,134)	(149,140)
Non-Controlling Interests
Changes in Total Equity (Deficit):
Balance at beginning of period				43,235				$ 59,939	43,235	59,939
Balance at end of period	28,944				43,235				28,944	43,235
Non-Controlling Interests | Preferred Units of Operating Partnership
Changes in Total Equity (Deficit):
Balance at beginning of period				127,268					127,268
Net income (loss)									2,273
Dividends and distributions									(2,273)
Balance at end of period	127,268				127,268				127,268	127,268
Non-Controlling Interests | Common Units of Operating Partnership
Changes in Total Equity (Deficit):
Balance at beginning of period				$ (84,033)					(84,033)
Net income (loss)									(14,291)
Dividends and distributions									0
Balance at end of period	$ (98,324)				$ (84,033)				$ (98,324)	$ (84,033)