Condensed Consolidated Statements of Equity - USD ($) $ in Thousands	Total	Common Stock [Member]	Additional Paid-in Capital [Member]	Cumulative Distributions in Excess of Earnings [Member]
Beginning balance at Dec. 31, 2015	$ 262,288	$ 477	$ 410,217	$ (148,406)
Beginning balance (in shares) at Dec. 31, 2015		47,664,742
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock, net	200,398	$ 170	200,228
Issuance of common stock, net, (in shares)		17,023,824
Vesting of restricted common stock, net of shares withheld for employee taxes	(515)	$ 1	(516)
Vesting of restricted common stock, net of shares withheld for employee taxes, (in shares)		127,784
Amortization of stock-based compensation	1,546		1,546
Common dividends ($0.185 and $0.68 per share for the six months ended 6/30/2017 and year ended 12/31/2016, respectively) (in usd per share)	(40,640)			(40,640)
Net income	29,353			29,353
Ending balance at Dec. 31, 2016	452,430	$ 648	611,475	(159,693)
Ending balance (in shares) at Dec. 31, 2016		64,816,350
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock, net	170,435	$ 106	170,329
Issuance of common stock, net, (in shares)		10,573,089
Vesting of restricted common stock, net of shares withheld for employee taxes	(866)	$ 1	(867)
Vesting of restricted common stock, net of shares withheld for employee taxes, (in shares)		77,543
Amortization of stock-based compensation	1,136		1,136
Common dividends ($0.185 and $0.68 per share for the six months ended 6/30/2017 and year ended 12/31/2016, respectively) (in usd per share)	(27,470)			(27,470)
Net income	12,311			12,311
Ending balance at Jun. 30, 2017	$ 607,976	$ 755	$ 782,073	$ (174,852)
Ending balance (in shares) at Jun. 30, 2017		75,466,982