CONDENSED CONSOLIDATED STATEMENT OF EQUITY - USD ($) $ in Thousands	Common Stock [Member]	Additional Paid-in Capital [Member]	Dividends in excess of net income [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Noncontrolling Interest [Member]	Total
Balance at Dec. 31, 2017	$ 3	$ 936,046	$ (28,763)	$ 1,375	$ 2,529	$ 911,190
Balance (in shares) at Dec. 31, 2017	31,004,900
Issuance of common stock, net of issuance costs		(93)				(93)
Repurchase of common shares		(1,074)				(1,074)
Repurchase of common shares (in shares)	(22,071)
Issuance of restricted stock under the Omnibus Incentive Plan (in shares)	50,841
Forfeiture of restricted stock (in shares)	(411)
Stock-based compensation		602				602
Dividends and distributions declared for the period			(16,137)		(181)	(16,318)
Other comprehensive income (loss) - change in fair value of interest rate swaps				1,899	21	1,920
Net income			16,451		185	16,636
Balance at Mar. 31, 2018	$ 3	935,481	(28,449)	3,274	2,554	912,863
Balance (in shares) at Mar. 31, 2018	31,033,259
Balance at Dec. 31, 2017	$ 3	936,046	(28,763)	1,375	2,529	911,190
Balance (in shares) at Dec. 31, 2017	31,004,900
Net income						45,460
Balance at Sep. 30, 2018	$ 3	1,096,679	(35,317)	4,506	2,507	1,068,378
Balance (in shares) at Sep. 30, 2018	34,481,545
Balance at Dec. 31, 2017	$ 3	936,046	(28,763)	1,375	2,529	911,190
Balance (in shares) at Dec. 31, 2017	31,004,900
Balance at Dec. 31, 2018	$ 4	1,277,592	(42,945)	1,424	2,411	1,238,486
Balance (in shares) at Dec. 31, 2018	37,545,790
Balance at Mar. 31, 2018	$ 3	935,481	(28,449)	3,274	2,554	912,863
Balance (in shares) at Mar. 31, 2018	31,033,259
Issuance of common stock, net of issuance costs		(339)				(339)
Stock-based compensation		686				686
Dividends and distributions declared for the period			(16,759)		(187)	(16,946)
Other comprehensive income (loss) - change in fair value of interest rate swaps				783	9	792
Net income			12,924		144	13,068
Balance at Jun. 30, 2018	$ 3	935,828	(32,284)	4,057	2,520	910,124
Balance (in shares) at Jun. 30, 2018	31,033,259
Issuance of common stock, net of issuance costs		160,036				160,036
Issuance of common stock, net of issuance costs (in shares)	3,450,000
Repurchase of common shares		(68)				(68)
Repurchase of common shares (in shares)	(277)
Forfeiture of restricted stock (in shares)	(1,437)
Stock-based compensation		883				883
Dividends and distributions declared for the period			(18,619)		(188)	(18,807)
Other comprehensive income (loss) - change in fair value of interest rate swaps				449	5	454
Net income			15,586		170	15,756
Balance at Sep. 30, 2018	$ 3	1,096,679	(35,317)	4,506	2,507	1,068,378
Balance (in shares) at Sep. 30, 2018	34,481,545
Balance at Dec. 31, 2018	$ 4	1,277,592	(42,945)	1,424	2,411	1,238,486
Balance (in shares) at Dec. 31, 2018	37,545,790
Issuance of common stock, net of issuance costs		57,845				57,845
Issuance of common stock, net of issuance costs (in shares)	874,268
Repurchase of common shares		(1,398)				(1,398)
Repurchase of common shares (in shares)	(21,868)
Issuance of restricted stock under the Omnibus Incentive Plan (in shares)	56,592
Stock-based compensation		913				913
Dividends and distributions declared for the period			(21,342)		(193)	(21,535)
Other comprehensive income (loss) - change in fair value of interest rate swaps				(3,374)	(31)	(3,405)
Net income			18,347		169	18,516
Balance at Mar. 31, 2019	$ 4	1,334,952	(45,940)	(1,950)	2,356	1,289,422
Balance (in shares) at Mar. 31, 2019	38,454,782
Balance at Dec. 31, 2018	$ 4	1,277,592	(42,945)	1,424	2,411	1,238,486
Balance (in shares) at Dec. 31, 2018	37,545,790
Balance at Jun. 30, 2019	$ 4	1,522,644	(51,298)	(5,711)	2,284	1,467,923
Balance (in shares) at Jun. 30, 2019	41,967,282
Balance at Dec. 31, 2018	$ 4	1,277,592	(42,945)	1,424	2,411	1,238,486
Balance (in shares) at Dec. 31, 2018	37,545,790
Net income						58,020
Balance at Sep. 30, 2019	$ 4	1,556,124	(54,841)	(13,068)	2,195	1,490,414
Balance (in shares) at Sep. 30, 2019	42,412,827
Balance at Mar. 31, 2019	$ 4	1,334,952	(45,940)	(1,950)	2,356	1,289,422
Balance (in shares) at Mar. 31, 2019	38,454,782
Issuance of common stock, net of issuance costs		186,667				186,667
Issuance of common stock, net of issuance costs (in shares)	3,512,500
Stock-based compensation		1,025				1,025
Dividends and distributions declared for the period			(23,922)		(197)	(24,119)
Other comprehensive income (loss) - change in fair value of interest rate swaps				(3,761)	(33)	(3,794)
Net income			18,564		158	18,722
Balance at Jun. 30, 2019	$ 4	1,522,644	(51,298)	(5,711)	2,284	1,467,923
Balance (in shares) at Jun. 30, 2019	41,967,282
Issuance of common stock, net of issuance costs		32,452				32,452
Issuance of common stock, net of issuance costs (in shares)	444,251
Repurchase of common shares		(4)				(4)
Repurchase of common shares (in shares)	(82)
Issuance of restricted stock under the Omnibus Incentive Plan (in shares)	1,399
Forfeiture of restricted stock		(2)				(2)
Forfeiture of restricted stock (in shares)	(23)
Stock-based compensation		1,034				1,034
Dividends and distributions declared for the period			(24,154)		(198)	(24,352)
Other comprehensive income (loss) - change in fair value of interest rate swaps				(7,357)	(61)	(7,418)
Net income			20,611		170	20,781
Balance at Sep. 30, 2019	$ 4	$ 1,556,124	$ (54,841)	$ (13,068)	$ 2,195	$ 1,490,414
Balance (in shares) at Sep. 30, 2019	42,412,827