Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
OPERATING ACTIVITIES
Net income	$ 42,755	$ 31,183	$ 12,759
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation of buildings and tenant improvements	23,453	18,678	14,984
Amortization of leasing costs and in-place lease intangibles	11,875	4,475	2,585
Accrued straight-line rental revenue	(1,091)	(1,924)	(2,203)
Amortization of leasing incentives and above or below-market rents	(85)	738	632
Accrued straight-line ground rent expense	371	290	315
Bad debt expense	203	131	79
Noncash stock compensation	1,082	931	917
Impairment charges	355	41	15
Noncash interest expense	980	1,006	517
Loss on extinguishment of debt	82	512	0
Gain on real estate dispositions	(30,533)	(18,394)	(2,211)
Change in the fair value of interest rate derivatives	941	229	233
Other noncash gain	0	0	(42)
Changes in operating assets and liabilities:
Property assets	(3,183)	(2,463)	(1,420)
Property liabilities	3,761	2,326	(1,069)
Construction assets	(6,385)	(17,337)	(5,893)
Construction liabilities	15,189	12,664	11,164
Net cash provided by operating activities	59,770	33,086	31,362
INVESTING ACTIVITIES
Development of real estate investments	(57,425)	(52,719)	(98,467)
Tenant and building improvements	(6,698)	(5,157)	(6,362)
Acquisitions of real estate investments	(195,645)	(68,445)	(2,754)
Dispositions of real estate investments	96,670	79,566	7,387
Notes receivable issuances	(51,721)	(7,825)	0
Government development grants	0	300	300
Decrease (increase) in restricted cash	(208)	1,580	(1,824)
Leasing costs	(2,374)	(2,118)	(2,835)
Leasing incentives	(236)	(1,563)	(751)
Contributions to real estate joint ventures	(8,824)	0	0
Net cash used for investing activities	(226,461)	(56,381)	(105,306)
FINANCING ACTIVITIES
Proceeds from sales of common stock	68,475	46,462	49,566
Offering costs	(1,453)	(427)	(416)
Debt issuances, credit facility and construction loan borrowings	316,852	214,407	117,645
Debt and credit facility repayments, including principal amortization	(186,533)	(206,889)	(63,306)
Debt issuance costs	(1,796)	(1,887)	(448)
Redemption of operating partnership units	(58)	(241)	0
Dividends and distributions	(33,843)	(27,024)	(22,096)
Net cash provided by financing activities	161,644	24,401	80,945
Net increase (decrease) in cash and cash equivalents	(5,047)	1,106	7,001
Cash and cash equivalents, beginning of period	26,989	25,883	18,882
Cash and cash equivalents, end of period	21,942	26,989	25,883
Supplemental cash flow information:
Cash paid for interest	(15,326)	(12,993)	(12,132)
Cash refunded (paid) for income taxes	(121)	276	(821)
Common shares and OP units issued for acquisitions	47,278	15,169	16,351
Change in accrued capital improvements and development costs	$ 8,183	$ 1,825	$ 2,608