CONDENSED CONSOLIDATED STATEMENT OF EQUITY - USD ($) $ in Thousands	Total	Class A Common Shares [Member]	Class B Common Shares [Member]	Class C Common Shares [Member]	Series A Preferred Shares [Member]	Additional Paid-In Capital [Member]	Accumulated Deficit [Member]	Non-Controlling Interest [Member]
Beginning balance at Dec. 31, 2017	$ 1,320,860	$ 324	$ 13	$ 31	$ 28	$ 1,116,060	$ (229,760)	$ 434,164
Beginning balance, shares at Dec. 31, 2017		32,416,000	1,329,000	3,151,000	2,800,000
Net income (loss)	16,201						10,328	5,873
Common dividends and distributions declared	(14,046)						(8,992)	(5,054)
Preferred dividends declared	(1,228)						(1,228)
Vesting of restricted share units, shares		14,000
Share-based compensation	869					869
Preferred stock offering costs	(88)					(88)
Stock issued in conversion of securities	1	$ 28
Stock issued in conversion securities, shares		2,779,121
Stock sold in conversion of securities, shares				(2,779,000)
Stock sold in conversion of securities				$ 27
Ending balance at Mar. 31, 2018	1,322,569	$ 352	$ 13	$ 4	$ 28	1,116,841	(229,652)	434,983
Ending balance, shares at Mar. 31, 2018		35,209,000	1,329,000	372,000	2,800,000
Beginning balance at Dec. 31, 2018	1,150,458	$ 357	$ 13		$ 28	1,124,504	(344,132)	369,688
Beginning balance, shares at Dec. 31, 2018		35,667,521	1,322,365		2,800,000
Net income (loss)	(10,894)						(6,967)	(3,927)
Cumulative effect of accounting change (see Note 2)	(1,286)						(1,286)
Common dividends and distributions declared	(14,026)						(8,996)	(5,030)
Preferred dividends declared	(1,225)						(1,225)
Vesting of restricted share units, shares		(23,000)
Vesting of restricted share units	(1,613)					(1,613)
Share-based compensation	1,566					1,566
Share-based compensation, shares		45,000
Ending balance at Mar. 31, 2019	$ 1,122,980	$ 357	$ 13		$ 28	$ 1,124,457	$ (362,606)	$ 360,731
Ending balance, shares at Mar. 31, 2019		35,689,708	1,322,365		2,800,000