Stockholders' Equity (Details) - USD ($) $ / shares in Units, $ in Thousands		3 Months Ended																12 Months Ended
		Dec. 31, 2018		Sep. 30, 2018		Jun. 30, 2018		Mar. 31, 2018		Dec. 31, 2017		Sep. 30, 2017		Jun. 30, 2017		Mar. 31, 2017		Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]
Net loss attributable to common stockholders		$ (12,785)		$ (10,334)		$ (10,212)		$ (9,425)		$ (46,241)		$ (12,017)		$ 17,569		$ (4,990)		$ (42,759)	$ (45,679)	$ (18,985)
Dividends on LTIP Units expected to vest																		(674)	0	(4)
Basic net loss attributable to common stockholders																		$ (43,433)	$ (45,679)	$ (18,989)
Weighted average common shares outstanding	[1]																	23,845,800	25,561,673	20,805,852
Potential dilutive shares	[2]																	0	0	0
Weighted average common shares outstanding and potential dilutive shares	[1]																	23,845,800	25,561,673	20,805,852
Net loss per common share, basic		$ (0.55)	[3]	$ (0.44)	[3]	$ (0.44)	[3]	$ (0.40)	[3]	$ (1.87)	[4]	$ (0.45)	[4]	$ 0.67	[4]	$ (0.20)	[4]	$ (1.82)	$ (1.79)	$ (0.91)
Net loss per common share, diluted		$ (0.55)	[3]	$ (0.44)	[3]	$ (0.44)	[3]	$ (0.40)	[3]	$ (1.87)	[4]	$ (0.45)	[4]	$ 0.67	[4]	$ (0.20)	[4]	$ (1.82)	$ (1.79)	$ (0.91)

[1] For 2018, amounts relate to shares of the Company’s Class A and Class C common stock outstanding. For 2017, amounts relate to shares of Class A and Class C common stock and LTIP Units outstanding. For 2016, amounts relate to shares of the Company’s Class A and B-3 common stock and LTIP Units outstanding.

[2] Excludes 194,338, 391 and 4,282 shares of common stock for the years ended December 31, 2018, 2017 and 2016, respectively, related to anti-dilutive, non-vested LTIP Units.

[3] EPS amounts are based on weighted average common shares outstanding during the quarter and, therefore, may not agree with the EPS calculated for the year ended December 31, 2018.

[4] EPS amounts are based on weighted average common shares outstanding during the quarter and, therefore, may not agree with the EPS calculated for the year ended December 31, 2017.