Consolidated Statements of Cash Flows - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2021		Dec. 31, 2020		Dec. 31, 2019
OPERATING ACTIVITIES
Net income		$ 25,455		$ 36,959		$ 32,258
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation of buildings and tenant improvements		51,549		43,671		37,839
Amortization of leasing costs, in-place lease intangibles and below market ground rents - operating leases		17,304		16,301		16,725
Accrued straight-line rental revenue		(4,938)		(5,927)		(3,402)
Amortization of leasing incentives and above or below-market rents		(1,065)		(814)		(629)
Amortization of right-of-use assets - finance leases		1,022		586		377
Accrued straight-line ground rent expense		236		100		(16)
Unrealized credit loss provision (release)		(792)		256		0
Adjustment for uncollectable lease accounts		945		3,842		511
Noncash stock compensation		2,230		2,378		1,613
Impairment charges		21,378		666		252
Noncash interest expense		2,878		2,204		1,228
Noncash loss on extinguishment of debt		3,810		0		30
Gain on real estate dispositions, net		(19,040)		(6,388)		(4,699)
Adjustment for Annapolis Junction modification fee	[1]	0		0		(4,489)
Change in the fair value of derivatives and other		(2,182)		1,130		3,599
Equity in income of unconsolidated real estate entities		0		0		(273)
Changes in operating assets and liabilities:
Property assets		(3,721)		(5,960)		(2,499)
Property liabilities		7,175		6,677		3,936
Construction assets		19,284		(2,302)		(20,356)
Construction liabilities		(27,904)		13,708		18,671
Interest receivable		(2,440)		(15,908)		(12,947)
Net cash provided by operating activities		91,184		91,179		67,729
INVESTING ACTIVITIES
Development of real estate investments		(48,625)		(63,485)		(133,445)
Tenant and building improvements		(15,496)		(10,077)		(19,721)
Acquisitions of real estate investments, net of cash received		(73,595)		(35,151)		(138,380)
Dispositions of real estate investments, net of selling costs		85,322		96,459		32,944
Notes receivable issuances		(30,656)		(24,484)		(54,555)
Notes receivable paydowns		42,301		16,340		22,522
Leasing costs		(4,585)		(3,425)		(3,893)
Leasing incentives		(688)		(1,326)		0
Contributions to equity method investments		(11,607)		(1,078)		(535)
Net cash used for investing activities		(57,629)		(26,227)		(295,063)
FINANCING ACTIVITIES
Proceeds from issuance of cumulative redeemable perpetual preferred stock, net		0		101,460		61,001
Proceeds from issuance of common stock, net		51,677		19,650		96,845
Common shares tendered for tax withholding		(553)		(569)		(369)
Debt issuances, credit facility and construction loan borrowings		161,806		176,619		427,286
Debt and credit facility repayments, including principal amortization		(187,758)		(299,318)		(270,851)
Debt issuance costs		(2,831)		(609)		(5,546)
Payment for debt extinguishment fee		(3,417)		0		0
Acquisition of NCI in consolidated RE investments		(804)		(5,002)		0
Redemption of operating partnership units		(2,949)		(2,729)		0
Dividends and distributions		(58,713)		(47,603)		(61,504)
Net cash (used for) provided by financing activities		(43,542)		(58,101)		246,862
Net (decrease) increase in cash, cash equivalents, and restricted cash		(9,987)		6,851		19,528
Cash, cash equivalents, and restricted cash, beginning of period		50,430	[2]	43,579	[2]	24,051
Cash, cash equivalents, and restricted cash, end of period	[2]	40,443		50,430		43,579
Supplemental cash flow information:
Cash paid for interest		29,237		28,554		28,878
Cash refunded for income taxes		4		167		247
Increase (decrease) in dividends and distributions payable		5,492		(5,724)		3,950
Common shares and OP units issued for acquisitions		0		6,099		73,169
Increase (decrease) in accrued capital improvements and development costs		15,111		(14,324)		(12,666)
Operating Partnership units redeemed for common shares		411		8,866		2,756
Note payable recorded for mandatorily redeemable partnership interest		0		3,829		0
Debt assumed at fair value in conjunction with real estate purchases		19,989		122,300		101,390
Note receivable extinguished in conjunction with real estate purchase		0		42,270		31,252
Equity method investment redeemed for real estate acquisition		0		0		23,011
Noncontrolling interest in acquired real estate entity		0		0		4,870
Note payable issued in acquisition of noncontrolling interest in real estate investment		0		6,130		0
Recognition of operating lease ROU assets	[3]	24,466		0		33,965
Recognition of operating lease liabilities	[3]	27,940		0		41,631
Recognition of finance lease right-of-use assets		0		0		24,500
Recognition of finance lease liabilities		0		0		17,871
De-recognition of operating lease ROU assets - lease termination		9,037		0		440
De-recognition of operating lease liabilities - lease termination		$ 10,143		$ 0		$ 440

[1] Borrower paid $5.0 million in 2018 in exchange for the Company's purchase option. This was accounted for as a loan modification fee; interest income was recognized as additional interest income on the note receivable over the one-year remaining term.

[2] The following table sets forth the items from the Company's consolidated balance sheets that are included in cash, cash equivalents, and restricted cash in the consolidated statements of cash flows:  As of December 31, 20212020Cash and cash equivalents$35,247 $40,998  Restricted cash (a) 5,196 9,432 Cash, cash equivalents, and restricted cash$40,443 $50,430  (a) Restricted cash represents amounts held by lenders for real estate taxes, insurance, and reserves for capital improvements.

[3] Amounts attributable to 2019 are net of $0.4 million related to the Company's preexisting lease at the Thames Street Wharf property, which was acquired on June 26, 2019.