Equity - Summary of Changes In Stockholders' Equity (Detail) - USD ($) $ in Thousands	3 Months Ended			6 Months Ended
	Jun. 30, 2019	Mar. 31, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Shareholders Equity [Line Items]
Balance	$ 1,129,746	$ 1,025,253	$ 794,692	$ 1,025,253	$ 791,089
Stock based compensation	695		712	1,431	1,576
Dividends and distributions paid	(20,275)		(14,772)	(38,709)	(29,196)
Issuance of common stock	26,441		273,015	152,164	286,504
Unrealized gain (loss) on interest rate swaps, net	(5,173)		662	(8,190)	2,521
Net income	6,491		1,719	6,010	3,534
Balance	$ 1,137,925	1,129,746	1,056,028	$ 1,137,925	1,056,028
Balance (in shares)	69,601,138			69,601,138
ASU 2016-02 [Member]
Shareholders Equity [Line Items]
Cumulative effect adjustment related to adoption of Leases				$ (34)
Common Stock Par Value [Member]
Shareholders Equity [Line Items]
Balance	$ 680	$ 608	$ 455	$ 608	$ 448
Balance (in shares)	68,005,907	60,849,206	45,458,706	60,849,206	44,787,040
Grant of unvested restricted stock				$ 1
Grant of unvested restricted stock (in shares)	32,840		21,328	89,961	21,328
Redemption of common units for shares of common stock	$ 1		$ 2	$ 1	$ 2
Redemption of common units for shares of common stock (in shares)	61,679		186,061	94,804	186,061
Issuance of common stock	$ 15		$ 147	$ 86	$ 154
Issuance of common stock (in share)	1,500,712		14,710,371	8,567,167	15,382,037
Balance	$ 696	$ 680	$ 604	$ 696	$ 604
Balance (in shares)	69,601,138		60,376,466	69,601,138	60,376,466
Additional Paid-in Capital [Member]
Shareholders Equity [Line Items]
Balance	$ 1,127,938	1,017,415	$ 741,089	$ 1,017,415	$ 740,546
Stock based compensation	210		100	394	181
Grant of unvested restricted stock				(1)
Redemption of common units for shares of common stock	1,011		3,037	1,504	3,037
Issuance of common stock	26,426		272,868	152,078	286,350
Allocation of non-controlling interest in Operating Partnership	(258)		(8,479)	(16,063)	(21,499)
Balance	1,155,327	1,127,938	1,008,615	1,155,327	1,008,615
Retained Earnings (Deficit) [Member]
Shareholders Equity [Line Items]
Balance	12,381	12,831	8,646	12,831	7,127
Net income	5,642		1,440	5,226	2,959
Balance	18,023	12,381	10,086	18,023	10,086
Retained Earnings (Deficit) [Member] | ASU 2016-02 [Member]
Shareholders Equity [Line Items]
Cumulative effect adjustment related to adoption of Leases				(34)
Cumulative Dividends [Member]
Shareholders Equity [Line Items]
Balance	(154,944)	(139,103)	(95,447)	(139,103)	(83,718)
Dividends and distributions paid	(17,698)		(12,126)	(33,539)	(23,855)
Balance	(172,642)	(154,944)	(107,573)	(172,642)	(107,573)
Accumulated Other Comprehensive Income (Loss) [Member]
Shareholders Equity [Line Items]
Balance	(219)	2,412	4,889	2,412	3,403
Unrealized gain (loss) on interest rate swaps, net	(4,532)		803	(7,163)	2,289
Balance	(4,751)	(219)	5,692	(4,751)	5,692
Non-controlling Interest in Operating Partnership [Member]
Shareholders Equity [Line Items]
Balance	143,910	131,090	135,060	131,090	123,283
Stock based compensation	485		612	1,037	1,395
Dividends and distributions paid	(2,577)		(2,646)	(5,170)	(5,341)
Redemption of common units for shares of common stock	(1,012)		(3,039)	(1,505)	(3,039)
Unrealized gain (loss) on interest rate swaps, net	(641)		(141)	(1,027)	232
Net income	849		279	784	575
Allocation of non-controlling interest in Operating Partnership	258		8,479	16,063	21,499
Balance	$ 141,272	$ 143,910	$ 138,604	$ 141,272	$ 138,604