Consolidated Statements of Stockholders' / Members' Equity (Unaudited) - USD ($) $ in Thousands	Total	Class A Units	Class B Units	Class C Units	Class D Units	Common Stock	Additional Paid-in Capital	Distributions in Excess of Retained Earnings	Total Stockholders' / Members' Equity	Non-Controlling Interests
Balance at Dec. 31, 2017	$ 181,402	$ 86,668	$ 574	$ 94,064	$ 96				$ 181,402
Contributions	50,000	50,000							50,000
Unit-based compensation expense	242		193		49				242
Net income	1,109	528		581					1,109
Balance at Mar. 31, 2018	232,753	$ 137,196	$ 767	$ 94,645	$ 145				232,753
Balance at Dec. 31, 2018	$ 811,041					$ 431	$ 569,407	$ (7,659)	562,179	$ 248,862
Balance, shares at Dec. 31, 2018	43,749,092					43,749,092
Common stock issued	$ 245,525					$ 140	245,385		245,525
Common stock issued, shares						14,030,000
Costs related to issuance of common stock	(10,887)						(10,887)		(10,887)
Share-based compensation expense	1,007						1,007		1,007
Share-based compensation expense, shares						46,368
Unit-based compensation expense	227						227		227
Dividends declared on common stock and OP Units	(16,145)							(12,143)	(12,143)	(4,002)
Net income	8,723							6,129	6,129	2,594
Balance at Mar. 31, 2019	$ 1,039,491					$ 571	$ 805,139	$ (13,673)	$ 792,037	$ 247,454
Balance, shares at Mar. 31, 2019	57,825,460					57,825,460