CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	3 Months Ended						9 Months Ended		12 Months Ended
	Sep. 30, 2021	Jun. 30, 2021	Mar. 31, 2021	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Sep. 30, 2021	Sep. 30, 2020	Dec. 31, 2020
Cash Flows from Operating Activities
Net income	$ 36,830	$ 22,461	$ 30,278	$ 21,416	$ 25,424	$ 21,370	$ 89,570	$ 68,210
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	24,488			17,327			69,164	47,067
Amortization from above (below) market lease intangibles, net							16,630	11,552
Amortization from financing and credit facility costs							1,581	1,029
Stock-based compensation							3,481	3,471
Provision for impairment	0			2,868			0	3,996
Gain (loss) on settlement of interest rate swaps							16,748	(23,169)
(Gain) loss on sale of assets							(13,182)	(7,567)
Write-off of unamortized finance costs upon debt extinguishment							1,250
(Increase) decrease in accounts receivable							(15,649)	(13,484)
(Increase) decrease in other assets							(1,513)	(1,364)
Increase (decrease) in accounts payable, accrued expenses, and other liabilities							17,887	1,114
Net Cash Provided by Operating Activities							185,967	90,855
Cash Flows from Investing Activities
Acquisition of real estate investments and other assets							(1,082,860)	(964,974)
Development of real estate investments, net of reimbursements (including capitalized interest of $200 in 2021, $109 in 2020)							(32,730)	(14,343)
Payment of leasing costs							(438)	(388)
Net proceeds from sale of assets							46,831	45,983
Net Cash Used in Investing Activities							(1,069,197)	(933,722)
Cash Flows from Financing Activities
Proceeds from Series A preferred stock offering, net							170,285
Proceeds from common stock offerings, net							650,859	629,586
Repurchase of common shares							(1,807)	(1,637)
Unsecured revolving credit facility borrowings (repayments), net							(92,000)	(69,000)
Payments of mortgage notes payable							(594)	(3,474)
Payments of unsecured term loans							(240,000)
Senior unsecured notes proceeds							640,623	349,745
Payment of common stock dividends							(147,133)	(83,798)
Distributions to non-controlling interest							(809)	(615)
Payments for financing costs							(1,341)	(3,867)
Net Cash Provided by Financing Activities							978,083	816,940
Net Increase (Decrease) in Cash and Cash Equivalents and Cash Held in Escrow							94,853	(25,927)
Cash and cash equivalents and cash held in escrow, beginning of period			$ 7,955			$ 42,157	7,955	42,157	$ 42,157
Cash and cash equivalents and cash held in escrow, end of period	102,808			16,230			102,808	16,230	7,955
Supplemental Disclosure of Cash Flow Information
Cash paid for interest (net of amounts capitalized)							30,799	25,351
Cash paid for income tax							1,794	1,137
Supplemental Disclosure of Non-Cash Investing and Financing Activities
Additional lease right of use assets added under new ground leases after January 1, 2019							6,302
Series A preferred dividends declared and unpaid	289						289
Common stock dividends and limited partners' distributions declared and unpaid	$ 15,507			$ 32,522			15,507	32,522	$ 34,545
Change in accrual of development, construction and other real estate investment costs							$ (1,731)	$ 7,665