CONSOLIDATED STATEMENTS OF EQUITY - USD ($) $ in Thousands	Total	Total Stockholders’ Equity	Common Stock	Additional Paid-in Capital	Cumulative Distributions in Excess of Net Income (Loss)	Noncontrolling Interest
Balance (in shares) at Dec. 31, 2018			177,523,853
Balance at Dec. 31, 2018	$ 930,895	$ 930,612	$ 1,775	$ 1,555,380	$ (626,543)	$ 283
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	262,067	262,091			262,091	(24)
Issuance of common stock (in shares)			3,434,259
Issuance of common stock	39,219	39,219	$ 34	39,185
Transfers from redeemable common stock	13,164	13,164		13,164
Redemptions of common stock (in shares)			(8,520,642)
Redemptions of common stock	(97,672)	(97,672)	$ (85)	(97,587)
Distributions declared	(85,285)	(85,285)			(85,285)
Other offering costs	(3)	(3)		(3)
Balance (in shares) at Sep. 30, 2019			172,437,470
Balance at Sep. 30, 2019	1,062,385	1,062,126	$ 1,724	1,510,139	(449,737)	259
Balance (in shares) at Jun. 30, 2019			175,001,561
Balance at Jun. 30, 2019	814,104	813,838	$ 1,750	1,550,351	(738,263)	266
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	316,877	316,884			316,884	(7)
Issuance of common stock (in shares)			1,116,391
Issuance of common stock	12,748	12,748	$ 11	12,737
Transfers to redeemable common stock	(10,864)	(10,864)		(10,864)
Redemptions of common stock (in shares)			(3,680,482)
Redemptions of common stock	(42,122)	(42,122)	$ (37)	(42,085)
Distributions declared	(28,358)	(28,358)			(28,358)
Balance (in shares) at Sep. 30, 2019			172,437,470
Balance at Sep. 30, 2019	$ 1,062,385	1,062,126	$ 1,724	1,510,139	(449,737)	259
Balance (in shares) at Dec. 31, 2019	180,970,743		180,970,743
Balance at Dec. 31, 2019	$ 985,310	985,055	$ 1,810	1,600,416	(617,171)	255
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	(12,131)	(18,276)			(18,276)	6,145
Issuance of common stock (in shares)			3,186,782
Issuance of common stock	35,277	35,277	$ 32	35,245
Transfers to redeemable common stock	(26,666)	(26,666)		(26,666)
Redemptions of common stock (in shares)			(741,247)
Redemptions of common stock	(8,635)	(8,635)	$ (8)	(8,627)
Distributions declared	(81,805)	(81,805)			(81,805)
Other offering costs	(15)	(15)		(15)
Distribution to noncontrolling interest	$ (6,400)	0				(6,400)
Balance (in shares) at Sep. 30, 2020	183,416,278		183,416,278
Balance at Sep. 30, 2020	$ 884,935	884,935	$ 1,834	1,600,353	(717,252)	0
Balance (in shares) at Jun. 30, 2020			182,564,608
Balance at Jun. 30, 2020	911,206	911,206	$ 1,826	1,600,363	(690,983)	0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	1,119	1,119			1,119	0
Issuance of common stock (in shares)			1,052,825
Issuance of common stock	11,655	11,655	$ 11	11,644
Transfers to redeemable common stock	(9,311)	(9,311)		(9,311)
Redemptions of common stock (in shares)			(201,155)
Redemptions of common stock	(2,343)	(2,343)	$ (3)	(2,340)
Distributions declared	(27,388)	(27,388)			(27,388)
Other offering costs	$ (3)	(3)		(3)
Balance (in shares) at Sep. 30, 2020	183,416,278		183,416,278
Balance at Sep. 30, 2020	$ 884,935	$ 884,935	$ 1,834	$ 1,600,353	$ (717,252)	$ 0