Equity and Earnings per Common Share, Earnings per Share (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
Numerator [Abstract]
Net income allocable to common stockholders	$ (38,810)	$ 27,499	$ 13,845	$ 35,239	$ 20,233	$ 6,859	$ (1,665)	$ 22,587	$ 37,773	$ 48,014	$ 25,243
Net income allocated to noncontrolling interests in Operating Partnership	505	(364)	(173)	(456)	(269)	(93)	119	(412)	(488)	(655)	(411)
Dividends on preferred stock	1,395	1,372	1,317	1,213	1,240	593	0	0	5,297	1,833	0
Net income attributable to common stockholders	$ (39,700)	$ 25,763	$ 12,355	$ 33,570	$ 18,724	$ 6,173	$ (1,546)	$ 22,175	$ 31,988	$ 45,526	$ 24,832
Denominator [Abstract]
Weighted average common shares outstanding (in shares)	16,382,914	15,864,774	13,616,461	12,713,265	12,713,265	12,703,577	12,695,090	7,634,038	14,649,242	11,443,493	7,512,444
Weighted average diluted shares outstanding (in shares)	16,391,170	15,873,030	13,624,676	12,721,464	12,721,464	12,711,776	12,701,715	7,640,348	14,657,498	11,450,831	7,523,297
Basic and Diluted [Abstract]
Basic (in dollars per share)	$ (2.42)	$ 1.62	$ 0.91	$ 2.64	$ 1.47	$ 0.49	$ (0.12)	$ 2.90	$ 2.18	$ 3.98	$ 3.31
Diluted (in dollars per share)	$ (2.42)	$ 1.62	$ 0.91	$ 2.64	$ 1.47	$ 0.49	$ (0.12)	$ 2.90	$ 2.18	$ 3.98	$ 3.30
Anti-dilutive securities (in shares)									0	0	0