Consolidated Statements of Equity - USD ($) $ in Thousands	Total	Total Stockholders’ Equity	Common Stock	Additional Paid-In Capital	Cumulative Distributions	Accumulated Income (Deficit)	Accumulated Other Comprehensive (Loss) Income	Non-controlling Interests
BALANCE at Dec. 31, 2016	$ 1,223,584	$ 1,193,470	$ 184	$ 1,561,508	$ (333,829)	$ (29,750)	$ (4,642)	$ 30,113
BALANCE (in shares) at Dec. 31, 2016			184,494,771
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Deferred equity compensation	173	173		173
Deferred equity compensation (in shares)			13,625
Cash distributions to common stockholders	(71,156)	(71,156)			(71,156)
Issuance of shares for distribution reinvestment plan			$ 5	49,536	(49,541)
Issuance of shares for distribution reinvestment plan (shares)			5,021,811
Repurchase of common stock	(98,905)	(98,905)	$ (10)	(98,895)
Repurchase of common stock (shares)			(10,408,640.30)
Reduction of common stock subject to redemption	49,365	49,365		49,365
Mergers	0
Distributions to noncontrolling interests	(4,369)							(4,369)
Distributions to noncontrolling interests subject to redemption	(13)							(13)
Net income	145,777	140,657				140,657		5,120
Other comprehensive income (loss)	7,356	7,102					7,102	254
BALANCE at Dec. 31, 2017	1,251,811	1,220,706	$ 179	1,561,686	(454,526)	110,907	2,460	31,105
BALANCE (in shares) at Dec. 31, 2017			179,121,568
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Deferred equity compensation	38	38		38
Deferred equity compensation (in shares)			8,035
Cash distributions to common stockholders	(75,613)	(75,613)			(75,613)
Issuance of shares for distribution reinvestment plan			$ 4	40,834	(40,838)
Issuance of shares for distribution reinvestment plan (shares)			4,262,336
Repurchase of common stock	(83,574)	(83,574)	$ (9)	(83,565)
Repurchase of common stock (shares)			(9,113,598)
Reduction of common stock subject to redemption	42,736	42,736		42,736
Redemptions in excess of distribution reinvestment plan	0	0		0
Issuance of limited partnership units	205,000							205,000
Issuance of stock dividend for noncontrolling interest								0
Mergers	0
Distributions to noncontrolling interests	(4,368)							(4,368)
Distributions to noncontrolling interests subject to redemption	(13)							(13)
Offering costs	(4,959)	(4,959)		(4,959)
Net income	18,407	17,618				17,618		789
Other comprehensive income (loss)	(5,179)	(4,869)					(4,869)	(310)
BALANCE at Dec. 31, 2018	$ 1,344,286	1,112,083	$ 174	1,556,770	(570,977)	128,525	(2,409)	232,203
BALANCE (in shares) at Dec. 31, 2018	174,278,341		174,278,341
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Gross proceeds from issuance of common stock	$ 9,383	9,383		9,383
Gross proceeds from issuance of common stock (shares)			973,490
Deferred equity compensation	2,623	2,623		2,623
Deferred equity compensation (in shares)			260,039
Cash distributions to common stockholders	(89,836)	(89,836)			(89,836)
Issuance of shares for distribution reinvestment plan	220	220	$ 4	41,056	(40,840)
Issuance of shares for distribution reinvestment plan (shares)			4,298,420
Repurchase of common stock	(296,659)	(296,659)	$ (30)	(296,629)
Repurchase of common stock (shares)			(31,290,588)
Reduction of common stock subject to redemption	(9,042)	(9,042)		(9,042)
Issuance of limited partnership units	25,000							25,000
Issuance of stock dividend for noncontrolling interest	1,861							1,861
Issuance of stock dividends	(1,948)	(1,948)	$ 2	12,189	(14,139)
Issuance of stock dividends (shares)			1,279,084
Mergers	751,277	746,238	$ 78	746,160				5,039
Mergers (shares)			78,054,934
Distributions to noncontrolling interests	(19,716)							(19,716)
Distributions to noncontrolling interests subject to redemption	(45)							(45)
Offering costs	(1,906)	(1,906)		(1,906)
Reclass of noncontrolling interest subject to redemption	3							3
Net income	28,536	24,787				24,787		3,749
Other comprehensive income (loss)	(22,520)	(19,466)					(19,466)	(3,054)
BALANCE at Dec. 31, 2019	$ 1,721,517	$ 1,476,477	$ 228	$ 2,060,604	$ (715,792)	$ 153,312	$ (21,875)	$ 245,040
BALANCE (in shares) at Dec. 31, 2019	227,853,720		227,853,720
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Mergers	$ 751,278
BALANCE (in shares) at Apr. 30, 2019	78,054,934