CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY AND REDEEMABLE NONCONTROLLING INTEREST - USD ($) $ in Thousands	Total	Redeemable Noncontrolling Interest	Common Stock	Capital in Excess of Par Value	Accumulated Loss	Accumulated Distributions	Accumulated Other Comprehensive Loss	Total Stockholders' Equity	Non- controlling Interest
Beginning Balance at Dec. 31, 2013	$ 451,981		$ 582	$ 500,361	$ (30,580)	$ (17,423)	$ (959)	$ 451,981
Beginning Balance (in shares) at Dec. 31, 2013			58,218,000
Subscriptions received for common stock through reinvestment plan	$ 572,324		$ 560	571,764				572,324
Subscriptions received for common stock through public offering and reinvestment plan (in shares)			56,006,000
Stock distributions			$ 24	(24)
Stock distributions, shares	2,400,000		2,356,000
Redemptions of common stock	$ (2,996)		$ (3)	(2,993)				(2,996)
Redemption of common stock, shares			(324,000)
Stock issuance and offering costs	(59,782)			(59,782)				(59,782)
Net loss	(52,511)				(52,511)			(52,511)
Other comprehensive income (loss)	(3,905)						(3,905)	(3,905)
Distributions to holders of promoted interest	(2,000)			(2,000)				(2,000)
Cash distributions declared and paid or reinvested	(31,919)					(31,919)		(31,919)
Contribution from noncontrolling interests	968	$ 568							$ 400
Ending Balance at Dec. 31, 2014	872,160	568	$ 1,163	1,007,326	(83,091)	(49,342)	(4,864)	871,192	400
Ending Balance (in shares) at Dec. 31, 2014			116,256,000
Subscriptions received for common stock through reinvestment plan	$ 588,704		$ 561	588,143				588,704
Subscriptions received for common stock through public offering and reinvestment plan (in shares)			55,956,000
Stock distributions			$ 32	(32)
Stock distributions, shares	3,200,000		3,196,000
Redemptions of common stock	$ (9,309)		$ (12)	(9,297)				(9,309)
Redemption of common stock, shares			(978,000)
Stock issuance and offering costs	(57,359)			(57,359)				(57,359)
Net loss	(68,093)	(17)			(68,055)			(68,055)	(21)
Other comprehensive income (loss)	(4,883)						(4,883)	(4,883)
Distribution to holder of noncontrolling interest	(23)								(23)
Cash distributions declared and paid or reinvested	(63,201)					(63,201)		(63,201)
Contribution from noncontrolling interests	1,106								1,106
Ending Balance at Dec. 31, 2015	$ 1,259,102	551	$ 1,744	1,528,781	(151,146)	(112,543)	(9,747)	1,257,089	1,462
Ending Balance (in shares) at Dec. 31, 2015	174,430,000		174,430,000
Subscriptions received for common stock through reinvestment plan	$ 42,554		$ 44	42,510				42,554
Subscriptions received for common stock through public offering and reinvestment plan (in shares)			4,365,000
Redemptions of common stock	(36,243)		$ (37)	(36,206)				(36,243)
Redemption of common stock, shares			(3,725,000)
Net loss	(31,784)	(79)			(31,667)			(31,667)	(38)
Other comprehensive income (loss)	1,884						1,884	1,884
Distribution to holder of noncontrolling interest	(38)								(38)
Distributions to holders of promoted interest	(6,650)			(6,650)				(6,650)
Cash distributions declared and paid or reinvested	(74,008)					(74,008)		(74,008)
Ending Balance at Dec. 31, 2016	$ 1,154,817	$ 472	$ 1,751	$ 1,528,435	$ (182,813)	$ (186,551)	$ (7,863)	$ 1,152,959	$ 1,386
Ending Balance (in shares) at Dec. 31, 2016	175,070,000		175,070,000