Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Cash flows from operating activities:
Net income	$ 25,874	$ 29,353	$ 10,034
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization (including a below-market ground lease)	39,176	31,980	24,133
Amortization of deferred financing costs	2,100	2,239	2,200
Loss on the extinguishment of debt	11,883	326	1,208
Amortization of stock-based compensation	2,416	1,546	1,522
Straight-line rental income	(344)	(150)	0
Noncash interest income	(686)	(737)	(945)
Interest income distribution from other real estate investment	1,500	0	0
Reserve for advances and deferred rent	10,414	0	0
Impairment of real estate investment	890	0	0
Loss on sale of real estate	0	265	0
Change in operating assets and liabilities:
Accounts and other receivables, net	(9,428)	(3,404)	(2,326)
Accounts receivable due from related party	0	0	2,275
Prepaid expenses and other assets	(273)	84	(86)
Accounts payable and accrued liabilities	5,278	2,929	2,239
Net cash provided by operating activities	88,800	64,431	40,254
Cash flows from investing activities:
Acquisitions of real estate	(296,517)	(281,228)	(232,466)
Improvements to real estate	(748)	(762)	(187)
Purchases of equipment, furniture and fixtures	(403)	(151)	(276)
Preferred equity investments	0	(4,656)	0
Investment in real estate mortgage loan receivable	(12,416)	0	0
Sale of other real estate investment	7,500	0	0
Principal payments received on mortgage loan receivable	25	0	0
Escrow deposits for acquisition of real estate	0	(700)	(1,750)
Net proceeds from the sale of real estate	0	2,855	30
Net cash used in investing activities	(302,559)	(284,642)	(234,649)
Cash flows from financing activities:
Proceeds from the issuance of common stock, net	170,323	200,402	162,963
Proceeds from the issuance of senior unsecured notes payable	300,000	0	0
Proceeds from the issuance of senior unsecured term loan	0	100,000	0
Borrowings under unsecured revolving credit facility	238,000	255,000	45,000
Payments on senior unsecured notes payable	(267,639)	0	0
Payments on unsecured revolving credit facility	(168,000)	(205,000)	0
Borrowings under senior secured revolving credit facility	0	0	35,000
Repayments of borrowings under senior secured revolving credit facility	0	0	(35,000)
Payments on the mortgage notes payable	0	(95,022)	(3,183)
Payments of deferred financing costs	(6,063)	(1,352)	(2,303)
Net-settle adjustment on restricted stock	(866)	(515)	(145)
Dividends paid on common stock	(52,587)	(37,269)	(21,790)
Net cash provided by financing activities	213,168	216,244	180,542
Net decrease in cash and cash equivalents	(591)	(3,967)	(13,853)
Cash and cash equivalents, beginning of period	7,500	11,467	25,320
Cash and cash equivalents, end of period	6,909	7,500	11,467
Supplemental disclosures of cash flow information:
Interest paid	29,619	21,238	21,687
Supplemental schedule of noncash operating, investing and financing activities:
Increase in dividends payable	2,970	3,371	3,758
Application of escrow deposit to acquisition of real estate	$ 700	$ 1,250	$ 500