Condensed Consolidated Statements of Cash Flows - USD ($)	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
OPERATING ACTIVITIES
Net income	$ 8,753,000	$ 26,533,000
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation of buildings and tenant improvements	6,473,000	5,468,000
Amortization of leasing costs and in-place lease intangibles	3,002,000	2,681,000
Accrued straight-line rental revenue	(383,000)	(188,000)
Amortization of leasing incentives and above or below-market rents	(47,000)	6,000
Accrued straight-line ground rent expense	138,000	66,000
Bad debt expense	68,000	45,000
Noncash stock compensation	411,000	437,000
Impairment charges	4,000	35,000
Noncash interest expense	277,000	191,000
Gain on real estate dispositions	(3,395,000)	(26,674,000)
Change in the fair value of derivatives	(294,000)	2,389,000
Changes in operating assets and liabilities:
Property assets	1,024,000	218,000
Property liabilities	(875,000)	(686,000)
Construction assets	(13,137,000)	4,857,000
Construction liabilities	5,888,000	(4,070,000)
Net cash provided by operating activities	7,907,000	11,308,000
INVESTING ACTIVITIES
Development of real estate investments	(6,456,000)	(19,777,000)
Tenant and building improvements	(2,069,000)	(1,309,000)
Acquisitions of real estate investments, net of cash received	(6,767,000)	(165,161,000)
Dispositions of real estate investments	4,441,000	83,748,000
Notes receivable issuances	(1,413,000)	(2,639,000)
(Decrease) increase in restricted cash	(31,000)	(13,000)
Leasing costs	(493,000)	(490,000)
Leasing incentives	0	(22,000)
Contributions to equity method investments	(559,000)	(5,440,000)
Net cash used for investing activities	(13,347,000)	(111,103,000)
FINANCING ACTIVITIES
Proceeds from sales of common stock	3,523,000	10,089,000
Offering costs	(161,000)	(273,000)
Debt issuances, credit facility and construction loan borrowings	44,952,000	144,684,000
Debt and credit facility repayments, including principal amortization	(44,530,000)	(54,821,000)
Debt issuance costs	(471,000)	(442,000)
Redemption of operating partnership units	(50,000)	0
Dividends and distributions	(9,726,000)	(7,621,000)
Net cash (used in) provided by financing activities	(6,463,000)	91,616,000
Net decrease in cash and cash equivalents	(11,903,000)	(8,179,000)
Cash and cash equivalents, beginning of period	21,942,000	26,989,000
Cash and cash equivalents, end of period	10,039,000	18,810,000
Noncash transactions:
Redeemable noncontrolling interest from development	2,000,000	0
Deferred payment for land acquisition	$ 600,000	$ 0