Condensed Consolidated Statements of Changes in Equity - USD ($) $ in Thousands	Total	Common Stock [Member] Class S Shares [Member]	Common Stock [Member] Class T Shares [Member]	Common Stock [Member] Class D Shares [Member]	Common Stock [Member] Class I Shares [Member]	Additional Paid-in Capital [Member]	Accumulated Deficit and Cumulative Distributions [Member]	Total Stockholders' Equity [Member]	Non-controlling Interests [Member]
Beginning Balance at Dec. 31, 2016	$ 85					$ 200	$ (115)	$ 85
Common stock issued	1,264,053	$ 978	$ 22	$ 12	$ 230	1,262,811		1,264,053
Offering costs	(98,938)					(98,938)		(98,938)
Distribution reinvestment	13,494	10			3	13,481		13,494
Common stock repurchased	(187)					(187)		(187)
Amortization of restricted stock grants	77					77		77
Net loss	(49,815)						(49,693)	(49,693)	$ (122)
Distributions declared on common stock	(25,321)						(25,321)	(25,321)
Contributions from non-controlling interests	8,978								8,978
Ending Balance at Sep. 30, 2017	1,112,426	988	22	12	233	1,177,444	(75,129)	1,103,570	8,856
Beginning Balance at Dec. 31, 2017	1,509,639	1,301	56	40	307	1,616,720	(132,633)	1,485,791	23,848
Common stock issued	2,082,218	1,045	134	201	560	2,080,278		2,082,218
Offering costs	(131,288)					(131,288)		(131,288)
Distribution reinvestment	66,898	42	2	3	15	66,836		66,898
Common stock repurchased	(30,603)	(15)		(2)	(11)	(30,575)		(30,603)
Amortization of restricted stock grants	112					112		112
Net loss	(160,345)
Net loss ($786 allocated to redeemable non-controlling interest)	(159,559)						(155,697)	(155,697)	(3,862)
Distributions declared on common stock	(114,881)						(114,881)	(114,881)
Contributions from non-controlling interests	80,216								80,216
Acquired non-controlling interests	12,802								12,802
Distributions to non-controlling interests	(2,215)								(2,215)
Allocation to redeemable non-controlling interests	(1,826)					(1,826)		(1,826)
Ending Balance at Sep. 30, 2018	$ 3,311,513	$ 2,373	$ 192	$ 242	$ 871	$ 3,600,257	$ (403,211)	$ 3,200,724	$ 110,789