Brandywine Operating Partnership 10-K 24 Feb 22 2021 FY Annual report Financial data

Cover Page

Cover Page - USD ($)	12 Months Ended
	Dec. 31, 2021	Feb. 17, 2022	Jun. 30, 2021
Document Information [Line Items]
Document Type	10-K
Document Annual Report	true
Document Period End Date	Dec. 31, 2021
Current Fiscal Year End Date	--12-31
Document Transition Report	false
Entity Registrant Name	Brandywine Realty Trust
Entity Incorporation, State or Country Code	MD
Entity File Number	001-9106
Entity Tax Identification Number	23-2413352
Entity Address, Address Line One	2929 Arch Street
Entity Address, Address Line Two	Suite 1800
Entity Address, City or Town	Philadelphia
Entity Address, State or Province	PA
Entity Address, Postal Zip Code	19104
City Area Code	610
Local Phone Number	325-5600
Title of 12(b) Security	Common Shares of Beneficial Interest
Trading Symbol	BDN
Security Exchange Name	NYSE
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
ICFR Auditor Attestation Flag	true
Entity Shell Company	false
Entity Public Float			$ 2,282,260,692
Entity Common Stock, Shares Outstanding		171,383,912
Documents Incorporated by Reference	Portions of the proxy statement for the 2022 Annual Meeting of Shareholders of Brandywine Realty Trust are incorporated by reference into Part III of this Form 10-K.
Entity Central Index Key	0000790816
Amendment Flag	false
Document Fiscal Year Focus	2021
Document Fiscal Period Focus	FY
BRANDYWINE OPERATING PARTNERSHIP, L.P.
Document Information [Line Items]
Entity Registrant Name	Brandywine Operating Partnership, L.P.
Entity Incorporation, State or Country Code	DE
Entity File Number	000-24407
Entity Tax Identification Number	23-2862640
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Non-accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
ICFR Auditor Attestation Flag	true
Entity Shell Company	false
Entity Central Index Key	0001060386

Audit Information

Audit Information	12 Months Ended
	Dec. 31, 2021
Auditor Information [Abstract]
Auditor Name	PricewaterhouseCoopers LLP
Auditor Location	Philadelphia, Pennsylvania
Auditor Firm ID	238

CONSOLIDATED BALANCE SHEETS

CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Real estate investments:
Operating properties	$ 3,472,602	$ 3,474,109
Accumulated depreciation	(957,450)	(896,561)
Right of use asset - operating leases, net	20,313	20,977
Operating real estate investments, net	2,535,465	2,598,525
Construction-in-progress	277,237	210,311
Land held for development	114,604	117,984
Prepaid leasehold interests in land held for development, net	27,762	39,185
Total real estate investments, net	2,955,068	2,966,005
Assets held for sale, net	562	7,349
Cash and cash equivalents	27,463	46,344
Accounts receivable	11,875	13,536
Accrued rent receivable, net of allowance of $4,133 and $5,086 as of December 31, 2021 and December 31, 2020, respectively	167,210	155,372
Investment in unconsolidated real estate ventures	435,506	401,327
Deferred costs, net	86,862	84,856
Intangible assets, net	28,556	48,570
Other assets	133,094	176,747
Total assets	3,846,196	3,900,106
LIABILITIES AND BENEFICIARIES' EQUITY
Unsecured credit facility	23,000	0
Unsecured term loan, net	249,608	249,084
Unsecured senior notes, net	1,580,978	1,581,511
Accounts payable and accrued expenses	150,151	121,982
Distributions payable	32,765	32,706
Deferred income, gains and rent	23,849	21,396
Intangible liabilities, net	12,981	18,448
Lease liability - operating leases	22,962	22,758
Other liabilities	48,683	47,573
Total liabilities	2,144,977	2,095,458
Commitments and contingencies (See Note 20)
Brandywine Operating Partnership, L.P.'s equity:
Common Shares of Brandywine Realty Trust's beneficial interest, $0.01 par value; shares authorized 400,000,000; 171,126,257 and 170,572,964 issued and outstanding as of December 31, 2021 and December 31, 2020, respectively	1,712	1,707
Additional paid-in-capital	3,146,786	3,138,152
Deferred compensation payable in common shares	18,491	17,516
Common shares in grantor trust, 1,169,703 and 1,160,494 issued and outstanding as of December 31, 2021 and December 31, 2020, respectively	(18,491)	(17,516)
Cumulative earnings	1,122,372	1,110,083
Accumulated other comprehensive loss	(2,020)	(7,561)
Cumulative distributions	(2,578,583)	(2,448,238)
Total Brandywine Realty Trust's equity	1,690,267	1,794,143
Noncontrolling interests	10,952	10,505
Total beneficiaries' equity	1,701,219	1,804,648
Total liabilities and partners' equity	$ 3,846,196	$ 3,900,106

CONSOLIDATED BALANCE SHEETS (Pa

CONSOLIDATED BALANCE SHEETS (Parenthetical) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Statement of Financial Position [Abstract]
Accrued rent receivable, allowance	$ 4,133	$ 5,086
Common stock, par or stated value per share (in usd per share)	$ 0.01	$ 0.01
Common stock, shares authorized (in shares)	400,000,000	400,000,000
Common shares in grantor trust, issued and outstanding (in shares)	1,169,703	1,160,494

CONSOLIDATED STATEMENTS OF OPER

CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Revenue
Total revenue	$ 486,819	$ 534,852	$ 580,417
Operating expenses
Property operating expenses	121,890	132,172	154,361
Real estate taxes	53,621	63,032	62,237
Third party management expenses	12,800	10,252	9,248
Depreciation and amortization	178,105	188,283	210,005
General and administrative expenses	30,153	30,288	32,156
Total operating expenses	396,569	424,027	468,007
Gain on sale of real estate
Net gain on disposition of real estate	142	289,461	356
Net gain on sale of undepreciated real estate	2,903	201	2,020
Total gain on sale of real estate	3,045	289,662	2,376
Operating income	93,295	400,487	114,786
Other income (expense):
Interest and investment income	8,295	1,939	2,318
Interest expense	(62,617)	(73,911)	(81,512)
Interest expense - amortization of deferred financing costs	(2,836)	(2,904)	(2,768)
Equity in income (loss) of real estate venture	(26,697)	(18,584)	(9,922)
Net gain on real estate venture transactions	2,973	75	11,639
Net income before income taxes	12,413	307,102	34,541
Income tax (provision) benefit	(47)	224	(12)
Net income	12,366	307,326	34,529
Net income attributable to noncontrolling interests	(77)	(1,799)	(262)
Net income attributable to Brandywine Realty Trust	12,289	305,527	34,267
Nonforfeitable dividends allocated to unvested restricted shareholders	(421)	(410)	(396)
Net income attributable to Common Shareholders/ Unitholders of Brandywine Realty Trust	$ 11,868	$ 305,117	$ 33,871
Basic income per Common Share (in dollars per shares)	$ 0.07	$ 1.77	$ 0.19
Diluted income per Common Share (in dollars per share)	$ 0.07	$ 1.77	$ 0.19
Basic weighted average shares outstanding (in shares)	170,878,185	171,926,079	176,132,941
Diluted weighted average shares outstanding (in shares)	172,273,240	172,317,076	176,686,813
Rents
Revenue
Total revenue	$ 451,519	$ 513,504	$ 554,665
Third party management fees, labor reimbursement and leasing
Revenue
Total revenue	26,444	18,580	19,626
Other
Revenue
Total revenue	$ 8,856	$ 2,768	$ 6,126

CONSOLIDATED STATEMENTS OF COMP

CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Statement of Comprehensive Income [Abstract]
Net income		$ 12,366	$ 307,326	$ 34,529
Comprehensive income (loss):
Unrealized gain (loss) on derivative financial instruments		4,817	(5,972)	(8,210)
Amortization of interest rate contracts	[1]	752	752	770
Total comprehensive income (loss)		5,569	(5,220)	(7,440)
Comprehensive income		17,935	302,106	27,089
Comprehensive income attributable to noncontrolling interest		(105)	(1,770)	(221)
Comprehensive income attributable to Brandywine Realty Trust/Brandywine Operating Partnership		$ 17,830	$ 300,336	$ 26,868
[1]	Amounts reclassified from comprehensive income to interest expense within the Consolidated Statements of Operations.

CONSOLIDATED STATEMENTS OF BENE

CONSOLIDATED STATEMENTS OF BENEFICIARIES’ EQUITY - USD ($) $ in Thousands	Total	Cumulative Effect, Period of Adoption, Adjustment	Common Stock	Deferred Compensation Payable in Common Shares	Additional Paid-in Capital	Common Shares in Grantor Trust	Cumulative Earnings	Cumulative EarningsCumulative Effect, Period of Adoption, Adjustment	Accumulated Other Comprehensive Income (Loss)	Cumulative Distributions	Noncontrolling Interests
Beginning balance (in shares) at Dec. 31, 2018			176,873,324	977,120
Beneficiaries' Equity, beginning balance at Dec. 31, 2018	$ 1,811,028	$ (5,336)	$ 1,770	$ 14,021	$ 3,200,312	$ (14,021)	$ 775,625	$ (5,336)	$ 5,029	$ (2,183,909)	$ 12,201
Parent Company
Net income	34,529						34,267				262
Other comprehensive income	$ (7,440)								(7,399)		(41)
Repurchase and retirement of Common Shares of Beneficial Interest (in shares)	(1,337,169)		(1,337,169)
Repurchase and retirement of Common Shares of Beneficial Interest	$ (17,281)		$ (13)		(17,268)
Issuance of partnership interest in consolidated real estate venture	27										27
Purchase of partnership interest in consolidated real estate venture	(2,180)				(983)						(1,197)
Redemption of LP Units (in shares)			1,245
Redemption of LP Units	0				16						(16)
Share-based compensation activity (in shares)			845,210	41,342
Share-based compensation activity	10,027		$ 9		10,018
Share Issuance from/(to) Deferred Compensation Plan (in shares)			97,485	87,080
Share Issuance from/(to) Deferred Compensation Plan	0			$ 2,195		(2,195)
Reallocation of Noncontrolling Interest	0				63						(63)
Distributions declared	(135,071)									(134,324)	(747)
Ending balance (in shares) at Dec. 31, 2019			176,480,095	1,105,542
Beneficiaries' Equity, ending balance at Dec. 31, 2019	1,688,303		$ 1,766	$ 16,216	3,192,158	(16,216)	804,556		(2,370)	(2,318,233)	10,426
Parent Company
Net income	307,326						305,527				1,799
Other comprehensive income	$ (5,220)								(5,191)		(29)
Repurchase and retirement of Common Shares of Beneficial Interest (in shares)	(6,248,483)		(6,248,483)
Repurchase and retirement of Common Shares of Beneficial Interest	$ (59,999)		$ (62)		(59,937)
Sale of partnership interest to consolidated real estate venture	(1,017)										(1,017)
Distributions from consolidated real estate venture	(22)										(22)
Share-based compensation activity (in shares)			309,096	50,967
Share-based compensation activity	6,236		$ 3		6,233
Share Issuance from/(to) Deferred Compensation Plan (in shares)			32,256	3,985
Share Issuance from/(to) Deferred Compensation Plan	(206)			$ 1,300	(206)	(1,300)
Reallocation of Noncontrolling Interest	0				(96)						96
Distributions declared	(130,753)									(130,005)	(748)
Ending balance (in shares) at Dec. 31, 2020			170,572,964	1,160,494
Beneficiaries' Equity, ending balance at Dec. 31, 2020	1,804,648		$ 1,707	$ 17,516	3,138,152	(17,516)	1,110,083		(7,561)	(2,448,238)	10,505
Parent Company
Net income	12,366						12,289				77
Other comprehensive income	5,569								5,541		28
Issuance of Common Shares of Beneficial Interest (in shares)			226,695
Issuance of Common Shares of Beneficial Interest	3,052		$ 3		3,049
Issuance of partnership interest in consolidated real estate venture	2,765										2,765
Redemption of LP Units	(2,334)										(2,334)
Share-based compensation activity (in shares)			344,656	70,645
Share-based compensation activity	6,354		$ 2		6,352
Share Issuance from/(to) Deferred Compensation Plan (in shares)			(18,058)	(61,436)
Share Issuance from/(to) Deferred Compensation Plan	(198)			$ 975	(198)	(975)
Reallocation of Noncontrolling Interest	0				(569)						569
Distributions declared	(131,003)									(130,345)	(658)
Ending balance (in shares) at Dec. 31, 2021			171,126,257	1,169,703
Beneficiaries' Equity, ending balance at Dec. 31, 2021	$ 1,701,219		$ 1,712	$ 18,491	$ 3,146,786	$ (18,491)	$ 1,122,372		$ (2,020)	$ (2,578,583)	$ 10,952

CONSOLIDATED STATEMENTS OF BE_2

CONSOLIDATED STATEMENTS OF BENEFICIARIES’ EQUITY (Parenthetical) - $ / shares	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Statement of Stockholders' Equity [Abstract]
Distributions declared per Common Share (in dollars per share)	$ 0.76	$ 0.76	$ 0.76

CONSOLIDATED STATEMENTS OF CASH

CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Cash flows from operating activities:
Net income	$ 12,366	$ 307,326	$ 34,529
Adjustments to reconcile net income to net cash from operating activities:
Depreciation and amortization	178,105	188,283	210,005
Amortization of deferred financing costs	2,836	2,904	2,768
Amortization of debt discount/(premium), net	(1,951)	(568)	189
Amortization of stock compensation costs	7,130	6,627	6,876
Straight-line rent income	(13,485)	(14,743)	(11,369)
Amortization of acquired above (below) market leases, net	(5,377)	(4,867)	(8,857)
Ground rent expense	918	1,455	1,470
Provision for doubtful accounts	0	1,049	(1,345)
Net gain on real estate venture transactions	(2,973)	(75)	(11,639)
Net gain on sale of interests in real estate	(3,045)	(289,662)	(2,376)
Loss from unconsolidated real estate ventures, net of distributions	26,697	18,584	10,242
Income tax provision (benefit)	47	(224)	12
Changes in assets and liabilities:
Accounts receivable	2,506	(2,031)	(248)
Other assets	(19,325)	(5,034)	9,368
Accounts payable and accrued expenses	2,974	14,374	(5,599)
Deferred income, gains and rent	2,986	(12,149)	9,319
Other liabilities	465	14,557	(9,115)
Net cash provided by operating activities	190,874	225,806	234,230
Cash flows from investing activities:
Acquisition of properties	0	(41,950)	0
Acquisition of partners interest in consolidated real estate venture	0	0	(2,181)
Proceeds from the sale of properties	10,303	278,114	41,795
Proceeds from real estate venture sales	0	0	9,730
Proceeds from insurance	1,250	0	0
Proceeds from note receivable	50,000	0	0
Issuance of note receivable	0	(50,000)	0
Proceeds from repayment of mortgage notes receivable	0	0	3,341
Capital expenditures for tenant improvements	(56,830)	(73,166)	(67,258)
Capital expenditures for redevelopments	(48,022)	(21,664)	(53,846)
Capital expenditures for developments	(30,269)	(65,420)	(77,192)
Advances for the purchase of tenant assets, net of repayments	270	1,488	(1,035)
Investment in unconsolidated real estate ventures	(31,643)	(719)	(253)
Deposits for real estate	(2,550)	0	(4,181)
Capital distributions from unconsolidated real estate ventures	27,028	9,001	35,906
Leasing costs paid	(19,852)	(17,394)	(15,485)
Net cash provided by (used in) investing activities	(100,315)	18,290	(130,659)
Cash flows from financing activities:
Repayments of mortgage notes payable	0	(94,993)	(7,595)
Proceeds from credit facility borrowings	154,000	318,000	348,500
Repayments of Long-term Lines of Credit	(131,000)	(318,000)	(441,000)
Proceeds from unsecured notes	0	0	216,373
Payments of Financing Costs	0	0	(1,965)
Exercise of stock options, net	(63)	47	3,771
Payments On Account Of Employee Tax Withholdings On Share Based Awards	(1,762)	(1,346)	(1,554)
Partner contributions to consolidated real estate venture	2,765	0	27
Repurchase and retirement of common shares	0	(60,000)	(17,282)
Redemption of limited partnership units	(2,334)	0	0
Distributions paid to shareholders	(130,255)	(131,150)	(134,140)
Distributions to noncontrolling interest	(687)	(747)	(747)
Net cash used in financing activities	(109,336)	(288,189)	(35,612)
Increase/(Decrease) in cash and cash equivalents and restricted cash	(18,777)	(44,093)	67,959
Cash and cash equivalents and restricted cash at beginning of year	47,077	91,170	23,211
Cash and cash equivalents and restricted cash at end of period	28,300	47,077	91,170
Reconciliation of cash and cash equivalents and restricted cash:
Cash and cash equivalents, beginning of period	46,344	90,499	22,842
Restricted cash, beginning of period	733	671	369
Cash and cash equivalents, end of period	27,463	46,344	90,499
Restricted cash, end of period	837	733	671
Cash and cash equivalents and restricted cash	28,300	47,077	91,170
Supplemental disclosure:
Cash paid for interest, net of capitalized interest during the years ended December 31, 2021, 2020 and 2019 of $8,689, $4,650 and $2,246 respectively	72,391	79,498	66,508
Cash paid for income taxes	785	688	1,385
Supplemental disclosure of non-cash activity:
Dividends and distributions declared but not paid	32,765	32,706	33,815
Change in investment in real estate ventures as a result of deconsolidation	32,761	0	1,806
Change in operating real estate from deconsolidation of operating properties	30,073	(427,710)	0
Change in investment in real estate ventures from deconsolidation of operating properties	0	(296,262)	0
Change in mortgage notes payable from deconsolidation of operating properties	0	(220,271)	0
Change in other assets as a result of deconsolidation of operating properties	(2,688)	1,471	0
Change in capital expenditures financed through accounts payable at period end	22,744	(9,949)	(10,618)
Change in capital expenditures financed through retention payable at period end	$ (613)	$ 284	$ (946)

CONSOLIDATED STATEMENTS OF CA_2

CONSOLIDATED STATEMENTS OF CASH FLOWS (Parenthetical) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Supplemental disclosure:
Capitalized interest	$ 8,689	$ 4,650	$ 2,246

CONSOLIDATED BALANCE SHEETS - B

CONSOLIDATED BALANCE SHEETS - BRANDYWINE OPERATING PARTNERSHIP, L.P. - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Real estate investments:
Operating properties	$ 3,472,602	$ 3,474,109
Accumulated depreciation	(957,450)	(896,561)
Right of use asset - operating leases, net	20,313	20,977
Operating real estate investments, net	2,535,465	2,598,525
Construction-in-progress	277,237	210,311
Land held for development	114,604	117,984
Prepaid leasehold interests in land held for development, net	27,762	39,185
Total real estate investments, net	2,955,068	2,966,005
Assets held for sale, net	562	7,349
Cash and cash equivalents	27,463	46,344
Accounts receivable	11,875	13,536
Accrued rent receivable, net of allowance of $4,133 and $5,086 as of December 31, 2021 and December 31, 2020, respectively	167,210	155,372
Investment in unconsolidated real estate ventures	435,506	401,327
Deferred costs, net	86,862	84,856
Intangible assets, net	28,556	48,570
Other assets	133,094	176,747
Total assets	3,846,196	3,900,106
LIABILITIES AND BENEFICIARIES' EQUITY
Unsecured credit facility	23,000	0
Unsecured term loan, net	249,608	249,084
Unsecured senior notes, net	1,580,978	1,581,511
Accounts payable and accrued expenses	150,151	121,982
Distributions payable	32,765	32,706
Deferred income, gains and rent	23,849	21,396
Intangible liabilities, net	12,981	18,448
Lease liability - operating leases	22,962	22,758
Other liabilities	48,683	47,573
Total liabilities	2,144,977	2,095,458
Commitments and contingencies (See Note 20)
Brandywine Operating Partnership, L.P.'s equity:
Accumulated other comprehensive loss	(2,020)	(7,561)
Total liabilities and partners' equity	3,846,196	3,900,106
BRANDYWINE OPERATING PARTNERSHIP, L.P.
Real estate investments:
Operating properties	3,472,602	3,474,109
Accumulated depreciation	(957,450)	(896,561)
Right of use asset - operating leases, net	20,313	20,977
Operating real estate investments, net	2,535,465	2,598,525
Construction-in-progress	277,237	210,311
Land held for development	114,604	117,984
Prepaid leasehold interests in land held for development, net	27,762	39,185
Total real estate investments, net	2,955,068	2,966,005
Assets held for sale, net	562	7,349
Cash and cash equivalents	27,463	46,344
Accounts receivable	11,875	13,536
Accrued rent receivable, net of allowance of $4,133 and $5,086 as of December 31, 2021 and December 31, 2020, respectively	167,210	155,372
Investment in unconsolidated real estate ventures	435,506	401,327
Deferred costs, net	86,862	84,856
Intangible assets, net	28,556	48,570
Other assets	133,094	176,747
Total assets	3,846,196	3,900,106
LIABILITIES AND BENEFICIARIES' EQUITY
Unsecured credit facility	23,000	0
Unsecured term loan, net	249,608	249,084
Unsecured senior notes, net	1,580,978	1,581,511
Accounts payable and accrued expenses	150,151	121,982
Distributions payable	32,765	32,706
Deferred income, gains and rent	23,849	21,396
Intangible liabilities, net	12,981	18,448
Lease liability - operating leases	22,962	22,758
Other liabilities	48,683	47,573
Total liabilities	2,144,977	2,095,458
Commitments and contingencies (See Note 20)
Redeemable limited partnership units at redemption value; 823,983 and 981,634 issued and outstanding as of December 31, 2021 and December 31, 2020, respectively	11,140	11,566
Brandywine Operating Partnership, L.P.'s equity:
General Partnership Capital; 171,126,257 and 170,572,964 units issued and outstanding as of December 31, 2021 and December 31, 2020, respectively	1,689,611	1,800,945
Accumulated other comprehensive loss	(2,366)	(7,935)
Total Brandywine Operating Partnership, L.P.'s equity	1,687,245	1,793,010
Noncontrolling interest - consolidated real estate ventures	2,834	72
Total partners' equity	1,690,079	1,793,082
Total liabilities and partners' equity	$ 3,846,196	$ 3,900,106

CONSOLIDATED BALANCE SHEETS -_2

CONSOLIDATED BALANCE SHEETS - BRANDYWINE OPERATING PARTNERSHIP, L.P. (Parenthetical) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Accrued rent receivable, allowance	$ 4,133	$ 5,086
BRANDYWINE OPERATING PARTNERSHIP, L.P.
Accrued rent receivable, allowance	$ 4,133	$ 5,086
Redeemable limited partnership units issued (in units)	823,983	981,634
Redeemable limited partnership units outstanding (in units)	823,983	981,634
Common stock, shares, outstanding (in shares)	171,126,257	170,572,964
Common stock, shares, issued (in shares)	171,126,257	170,572,964

CONSOLIDATED STATEMENTS OF OP_2

CONSOLIDATED STATEMENTS OF OPERATIONS - BRANDYWINE OPERATING PARTNERSHIP, L.P. - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Revenue
Total revenue	$ 486,819	$ 534,852	$ 580,417
Operating expenses
Property operating expenses	121,890	132,172	154,361
Real estate taxes	53,621	63,032	62,237
Third party management expenses	12,800	10,252	9,248
Depreciation and amortization	178,105	188,283	210,005
General and administrative expenses	30,153	30,288	32,156
Total operating expenses	396,569	424,027	468,007
Gain on sale of real estate
Net gain on disposition of real estate	142	289,461	356
Net gain on sale of undepreciated real estate	2,903	201	2,020
Total gain on sale of real estate	3,045	289,662	2,376
Operating income	93,295	400,487	114,786
Other income (expense):
Interest and investment income	8,295	1,939	2,318
Interest expense	(62,617)	(73,911)	(81,512)
Interest expense - amortization of deferred financing costs	(2,836)	(2,904)	(2,768)
Equity in income (loss) of real estate venture	(26,697)	(18,584)	(9,922)
Net gain on real estate venture transactions	2,973	75	11,639
Net income before income taxes	12,413	307,102	34,541
Income tax (provision) benefit	(47)	224	(12)
Net income	12,366	307,326	34,529
Nonforfeitable dividends allocated to unvested restricted shareholders	(421)	(410)	(396)
Net income attributable to Common Shareholders/ Unitholders of Brandywine Realty Trust	$ 11,868	$ 305,117	$ 33,871
Basic income per Common Partnership Unit (in dollars per share)	$ 0.07	$ 1.77	$ 0.19
Diluted income per Common Partnership Unit (in dollars per share)	$ 0.07	$ 1.77	$ 0.19
Basic weighted average common partnership units outstanding (in shares)	170,878,185	171,926,079	176,132,941
Diluted weighted average common partnership units outstanding (in shares)	172,273,240	172,317,076	176,686,813
Rents
Revenue
Total revenue	$ 451,519	$ 513,504	$ 554,665
Third party management fees, labor reimbursement and leasing
Revenue
Total revenue	26,444	18,580	19,626
Other
Revenue
Total revenue	8,856	2,768	6,126
BRANDYWINE OPERATING PARTNERSHIP, L.P.
Revenue
Total revenue	486,819	534,852	580,417
Operating expenses
Property operating expenses	121,890	132,172	154,361
Real estate taxes	53,621	63,032	62,237
Third party management expenses	12,800	10,252	9,248
Depreciation and amortization	178,105	188,283	210,005
General and administrative expenses	30,153	30,288	32,156
Total operating expenses	396,569	424,027	468,007
Gain on sale of real estate
Net gain on disposition of real estate	142	289,461	356
Net gain on sale of undepreciated real estate	2,903	201	2,020
Total gain on sale of real estate	3,045	289,662	2,376
Operating income	93,295	400,487	114,786
Other income (expense):
Interest and investment income	8,295	1,939	2,318
Interest expense	(62,617)	(73,911)	(81,512)
Interest expense - amortization of deferred financing costs	(2,836)	(2,904)	(2,768)
Equity in income (loss) of real estate venture	(26,697)	(18,584)	(9,922)
Net gain on real estate venture transactions	2,973	75	11,639
Net income before income taxes	12,413	307,102	34,541
Income tax (provision) benefit	(47)	224	(12)
Net income	12,366	307,326	34,529
Net (income) loss attributable to noncontrolling interests - consolidated real estate ventures	3	(20)	(69)
Net income attributable to Brandywine Operating Partnership	12,369	307,306	34,460
Nonforfeitable dividends allocated to unvested restricted shareholders	(421)	(410)	(396)
Net income attributable to Common Shareholders/ Unitholders of Brandywine Realty Trust	$ 11,948	$ 306,896	$ 34,064
Basic income per Common Partnership Unit (in dollars per share)	$ 0.07	$ 1.77	$ 0.19
Diluted income per Common Partnership Unit (in dollars per share)	$ 0.07	$ 1.77	$ 0.19
Basic weighted average common partnership units outstanding (in shares)	171,770,843	172,907,713	177,114,932
Diluted weighted average common partnership units outstanding (in shares)	173,165,898	173,298,710	177,668,804
BRANDYWINE OPERATING PARTNERSHIP, L.P. | Rents
Revenue
Total revenue	$ 451,519	$ 513,504	$ 554,665
BRANDYWINE OPERATING PARTNERSHIP, L.P. | Third party management fees, labor reimbursement and leasing
Revenue
Total revenue	26,444	18,580	19,626
BRANDYWINE OPERATING PARTNERSHIP, L.P. | Other
Revenue
Total revenue	$ 8,856	$ 2,768	$ 6,126

CONSOLIDATED STATEMENTS OF CO_2

CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - BRANDYWINE OPERATING PARTNERSHIP, L.P. - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Net income		$ 12,366	$ 307,326	$ 34,529
Comprehensive income (loss):
Unrealized gain (loss) on derivative financial instruments		4,817	(5,972)	(8,210)
Amortization of interest rate contracts	[1]	752	752	770
Total comprehensive income (loss)		5,569	(5,220)	(7,440)
Comprehensive income		17,935	302,106	27,089
Comprehensive (income) loss attributable to noncontrolling interest - consolidated real estate ventures		(105)	(1,770)	(221)
Comprehensive income attributable to Brandywine Realty Trust/Brandywine Operating Partnership		17,830	300,336	26,868
BRANDYWINE OPERATING PARTNERSHIP, L.P.
Net income		12,366	307,326	34,529
Comprehensive income (loss):
Unrealized gain (loss) on derivative financial instruments		4,817	(5,972)	(8,210)
Amortization of interest rate contracts	[1]	752	752	770
Total comprehensive income (loss)		5,569	(5,220)	(7,440)
Comprehensive income		17,935	302,106	27,089
Comprehensive (income) loss attributable to noncontrolling interest - consolidated real estate ventures		3	(20)	(69)
Comprehensive income attributable to Brandywine Realty Trust/Brandywine Operating Partnership		$ 17,938	$ 302,086	$ 27,020
[1]	Amounts reclassified from comprehensive income to interest expense within the Consolidated Statements of Operations.

CONSOLIDATED STATEMENTS OF PART

CONSOLIDATED STATEMENTS OF PARTNERS’ EQUITY - USD ($) $ in Thousands	Total	Accumulated Other Comprehensive Income (Loss)	Noncontrolling Interest - Consolidated Real Estate Ventures	BRANDYWINE OPERATING PARTNERSHIP, L.P.	BRANDYWINE OPERATING PARTNERSHIP, L.P.Cumulative Effect, Period of Adoption, Adjustment	BRANDYWINE OPERATING PARTNERSHIP, L.P.Accumulated Other Comprehensive Income (Loss)	BRANDYWINE OPERATING PARTNERSHIP, L.P.Noncontrolling Interest - Consolidated Real Estate Ventures	BRANDYWINE OPERATING PARTNERSHIP, L.P.General Partner Capital	BRANDYWINE OPERATING PARTNERSHIP, L.P.General Partner CapitalCumulative Effect, Period of Adoption, Adjustment
Beginning balance (in shares) at Dec. 31, 2018								176,873,324
Partners' Equity, beginning balance at Dec. 31, 2018				$ 1,798,508	$ (5,336)	$ 4,725	$ 2,192	$ 1,791,591	$ (5,336)
Net income	$ 34,529		$ 262	34,529			69	$ 34,460
Other comprehensive loss	(7,440)	$ (7,399)	(41)	(7,440)		(7,440)
Deferred compensation obligation (in shares)								97,485
Deferred compensation obligation	0
Conversion of LP Units to common shares (in shares)								1,245
Conversion of LP Units to common shares				16				$ 16
Repurchase and retirement of LP units (in shares)								(1,337,169)
Repurchase and retirement of LP units				(17,297)				$ (17,297)
Issuance of partnership interest in consolidated real estate venture	27		27	27			27
Share-based compensation activity (in shares)								845,210
Share-based compensation activity	10,027			10,027				$ 10,027
Purchase of partnership interest in consolidated real estate venture	(2,180)		(1,197)				(1,197)	(983)
Adjustment of redeemable partnership units to liquidation value at period end				(3,615)				(3,615)
Distributions declared to general partnership unitholders				(134,324)				$ (134,324)
Ending balance (in shares) at Dec. 31, 2019								176,480,095
Partners' Equity, ending balance at Dec. 31, 2019				1,672,915		(2,715)	1,091	$ 1,674,539
Net income	307,326		1,799	307,326			20	$ 307,306
Other comprehensive loss	(5,220)	(5,191)	(29)	(5,220)		(5,220)
Deferred compensation obligation (in shares)								32,256
Deferred compensation obligation	(206)			(206)				$ (206)
Repurchase and retirement of LP units (in shares)								(6,248,483)
Repurchase and retirement of LP units				(59,999)				$ (59,999)
Distributions from consolidated real estate venture	(22)		(22)	(22)			(22)
Share-based compensation activity (in shares)								309,096
Share-based compensation activity	6,236			6,236				$ 6,236
Sale of partnership interest to consolidated real estate venture	(1,017)		(1,017)
Adjustment of redeemable partnership units to liquidation value at period end				3,074				3,074
Distributions declared to general partnership unitholders				(130,005)				$ (130,005)
Ending balance (in shares) at Dec. 31, 2020								170,572,964
Partners' Equity, ending balance at Dec. 31, 2020				1,793,082		(7,935)	72	$ 1,800,945
Net income	12,366		77	12,366			(3)	$ 12,369
Other comprehensive loss	5,569	$ 5,541	28	5,569		5,569
Deferred compensation obligation (in shares)								(18,058)
Deferred compensation obligation	(198)			(198)				$ (198)
Units issued to acquire noncontrolling interest (in units)								226,695
Partners' Capital Account, Acquisitions				3,052				$ 3,052
Repurchase and retirement of LP units				(2,334)				$ (2,334)
Issuance of partnership interest in consolidated real estate venture	2,765		$ 2,765	2,765			2,765
Share-based compensation activity (in shares)								344,656
Share-based compensation activity	$ 6,354			6,354				$ 6,354
Adjustment of redeemable partnership units to liquidation value at period end				(232)				(232)
Distributions declared to general partnership unitholders				(130,345)				$ (130,345)
Ending balance (in shares) at Dec. 31, 2021								171,126,257
Partners' Equity, ending balance at Dec. 31, 2021				$ 1,690,079		$ (2,366)	$ 2,834	$ 1,689,611

CONSOLIDATED STATEMENTS OF PA_2

CONSOLIDATED STATEMENTS OF PARTNERS’ EQUITY (Parenthetical) - $ / shares	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
BRANDYWINE OPERATING PARTNERSHIP, L.P.
Distributions to general partnership unitholders (in dollars per share)	$ 0.76	$ 0.76	$ 0.76

CONSOLIDATED STATEMENTS OF CA_3

CONSOLIDATED STATEMENTS OF CASH FLOWS - BRANDYWINE OPERATING PARTNERSHIP L.P. - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Cash flows from operating activities:
Net income	$ 12,366	$ 307,326	$ 34,529
Adjustments to reconcile net income to net cash from operating activities:
Depreciation and amortization	178,105	188,283	210,005
Amortization of deferred financing costs	2,836	2,904	2,768
Amortization of debt discount/(premium), net	(1,951)	(568)	189
Amortization of stock compensation costs	7,130	6,627	6,876
Straight-line rent income	(13,485)	(14,743)	(11,369)
Amortization of acquired above (below) market leases, net	(5,377)	(4,867)	(8,857)
Ground rent expense	918	1,455	1,470
Provision for doubtful accounts	0	1,049	(1,345)
Net gain on real estate venture transactions	(2,973)	(75)	(11,639)
Net gain on sale of interests in real estate	(3,045)	(289,662)	(2,376)
Loss from unconsolidated real estate ventures, net of distributions	26,697	18,584	10,242
Income tax provision (benefit)	47	(224)	12
Changes in assets and liabilities:
Accounts receivable	2,506	(2,031)	(248)
Other assets	(19,325)	(5,034)	9,368
Accounts payable and accrued expenses	2,974	14,374	(5,599)
Deferred income, gains and rent	2,986	(12,149)	9,319
Other liabilities	465	14,557	(9,115)
Net cash provided by operating activities	190,874	225,806	234,230
Cash flows from investing activities:
Acquisition of properties	0	(41,950)	0
Acquisition of partners interest in consolidated real estate venture	0	0	(2,181)
Proceeds from the sale of properties	10,303	278,114	41,795
Proceeds from real estate venture sales	0	0	9,730
Proceeds from insurance	1,250	0	0
Proceeds from note receivable	50,000	0	0
Issuance of note receivable	0	(50,000)	0
Proceeds from repayment of mortgage notes receivable	0	0	3,341
Capital expenditures for tenant improvements	(56,830)	(73,166)	(67,258)
Capital expenditures for redevelopments	(48,022)	(21,664)	(53,846)
Capital expenditures for developments	(30,269)	(65,420)	(77,192)
Advances for the purchase of tenant assets, net of repayments	270	1,488	(1,035)
Investment in unconsolidated real estate ventures	(31,643)	(719)	(253)
Deposits for real estate	(2,550)	0	(4,181)
Capital distributions from unconsolidated real estate ventures	27,028	9,001	35,906
Leasing costs paid	(19,852)	(17,394)	(15,485)
Net cash provided by (used in) investing activities	(100,315)	18,290	(130,659)
Cash flows from financing activities:
Repayments of mortgage notes payable	0	(94,993)	(7,595)
Proceeds from credit facility borrowings	154,000	318,000	348,500
Repayments of credit facility borrowings	(131,000)	(318,000)	(441,000)
Proceeds from unsecured notes	0	0	216,373
Debt financing costs paid	0	0	(1,965)
Shares used for employee taxes upon vesting of share awards	(1,762)	(1,346)	(1,554)
Partner contributions to consolidated real estate venture	2,765	0	27
Repurchase and retirement of common shares	0	(60,000)	(17,282)
Redemption of limited partnership units	(2,334)	0	0
Distributions paid to preferred and common partnership units	(130,255)	(131,150)	(134,140)
Net cash used in financing activities	(109,336)	(288,189)	(35,612)
Increase/(Decrease) in cash and cash equivalents and restricted cash	(18,777)	(44,093)	67,959
Cash and cash equivalents and restricted cash at beginning of year	47,077	91,170	23,211
Cash and cash equivalents and restricted cash at end of period	28,300	47,077	91,170
Reconciliation of cash and cash equivalents and restricted cash:
Cash and cash equivalents, beginning of period	46,344	90,499	22,842
Restricted cash, beginning of period	733	671	369
Cash and cash equivalents, end of period	27,463	46,344	90,499
Restricted cash, end of period	837	733	671
Cash and cash equivalents and restricted cash	28,300	47,077	91,170
Supplemental disclosure:
Cash paid for interest, net of capitalized interest during the years ended December 31, 2021, 2020 and 2019 of $8,689, $4,650 and $2,246 respectively	72,391	79,498	66,508
Cash paid for income taxes	785	688	1,385
Supplemental disclosure of non-cash activity:
Dividends and distributions declared but not paid	32,765	32,706	33,815
Change in investment in real estate ventures as a result of deconsolidation	32,761	0	1,806
Change in operating real estate from deconsolidation of operating properties	(30,073)	427,710	0
Change in investment in real estate ventures from deconsolidation of operating properties	0	(296,262)	0
Change in mortgage notes payable from deconsolidation of operating properties	0	(220,271)	0
Change in other assets as a result of deconsolidation of operating properties	(2,688)	1,471	0
Change in capital expenditures financed through accounts payable at period end	22,744	(9,949)	(10,618)
Change in capital expenditures financed through retention payable at period end	(613)	284	(946)
BRANDYWINE OPERATING PARTNERSHIP, L.P.
Cash flows from operating activities:
Net income	12,366	307,326	34,529
Adjustments to reconcile net income to net cash from operating activities:
Depreciation and amortization	178,105	188,283	210,005
Amortization of deferred financing costs	2,836	2,904	2,768
Amortization of debt discount/(premium), net	(1,951)	(568)	189
Amortization of stock compensation costs	7,130	6,627	6,876
Straight-line rent income	(13,485)	(14,743)	(11,369)
Amortization of acquired above (below) market leases, net	(5,377)	(4,867)	(8,857)
Ground rent expense	918	1,455	1,470
Provision for doubtful accounts	0	1,049	(1,345)
Net gain on real estate venture transactions	(2,973)	(75)	(11,639)
Net gain on sale of interests in real estate	(3,045)	(289,662)	(2,376)
Loss from unconsolidated real estate ventures, net of distributions	26,697	18,584	10,242
Income tax provision (benefit)	47	(224)	12
Changes in assets and liabilities:
Accounts receivable	2,506	(2,031)	(248)
Other assets	(19,325)	(5,034)	9,368
Accounts payable and accrued expenses	2,974	14,374	(5,599)
Deferred income, gains and rent	2,986	(12,149)	9,319
Other liabilities	465	14,557	(9,115)
Net cash provided by operating activities	190,874	225,806	234,230
Cash flows from investing activities:
Acquisition of properties	0	(41,950)	0
Acquisition of partners interest in consolidated real estate venture	0	0	(2,181)
Proceeds from the sale of properties	10,303	278,114	41,795
Proceeds from real estate venture sales	0	0	9,730
Proceeds from insurance	1,250	0	0
Proceeds from note receivable	50,000	0	0
Issuance of note receivable	0	(50,000)	0
Proceeds from repayment of mortgage notes receivable	0	0	3,341
Capital expenditures for tenant improvements	(56,830)	(73,166)	(67,258)
Capital expenditures for redevelopments	(48,022)	(21,664)	(53,846)
Capital expenditures for developments	(30,269)	(65,420)	(77,192)
Advances for the purchase of tenant assets, net of repayments	270	1,488	(1,035)
Investment in unconsolidated real estate ventures	(31,643)	(719)	(253)
Deposits for real estate	(2,550)	0	(4,181)
Capital distributions from unconsolidated real estate ventures	27,028	9,001	35,906
Leasing costs paid	(19,852)	(17,394)	(15,485)
Net cash provided by (used in) investing activities	(100,315)	18,290	(130,659)
Cash flows from financing activities:
Repayments of mortgage notes payable	0	(94,993)	(7,595)
Proceeds from credit facility borrowings	154,000	318,000	348,500
Repayments of credit facility borrowings	(131,000)	(318,000)	(441,000)
Proceeds from unsecured notes	0	0	216,373
Debt financing costs paid	0	0	(1,965)
Exercise of stock options, net	(63)	47	3,771
Shares used for employee taxes upon vesting of share awards	(1,762)	(1,346)	(1,554)
Partner contributions to consolidated real estate venture	2,765	0	27
Repurchase and retirement of common shares	0	(60,000)	(17,282)
Redemption of limited partnership units	(2,334)	0	0
Distributions paid to preferred and common partnership units	(130,942)	(131,897)	(134,887)
Net cash used in financing activities	(109,336)	(288,189)	(35,612)
Increase/(Decrease) in cash and cash equivalents and restricted cash	(18,777)	(44,093)	67,959
Cash and cash equivalents and restricted cash at beginning of year	47,077	91,170	23,211
Cash and cash equivalents and restricted cash at end of period	28,300	47,077	91,170
Reconciliation of cash and cash equivalents and restricted cash:
Cash and cash equivalents, beginning of period	46,344	90,499	22,842
Restricted cash, beginning of period	733	671	369
Cash and cash equivalents, end of period	27,463	46,344	90,499
Restricted cash, end of period	837	733	671
Cash and cash equivalents and restricted cash	28,300	47,077	91,170
Supplemental disclosure:
Cash paid for interest, net of capitalized interest during the years ended December 31, 2021, 2020 and 2019 of $8,689, $4,650 and $2,246 respectively	72,391	79,498	66,508
Cash paid for income taxes	785	688	1,385
Supplemental disclosure of non-cash activity:
Dividends and distributions declared but not paid	32,765	32,706	33,815
Change in investment in real estate ventures as a result of deconsolidation	32,761	0	1,806
Change in operating real estate from deconsolidation of operating properties	(30,073)	427,710	0
Change in investment in real estate ventures from deconsolidation of operating properties	0	(296,262)	0
Change in mortgage notes payable from deconsolidation of operating properties	0	(220,271)	0
Change in other assets as a result of deconsolidation of operating properties	(2,688)	1,471	0
Change in capital expenditures financed through accounts payable at period end	22,744	(9,949)	(10,618)
Change in capital expenditures financed through retention payable at period end	$ (613)	$ 284	$ (946)

CONSOLIDATED STATEMENTS OF CA_4

CONSOLIDATED STATEMENTS OF CASH FLOWS - BRANDYWINE OPERATING PARTNERSHIP L.P. (Parenthetical) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Capitalized interest	$ 8,689	$ 4,650	$ 2,246
BRANDYWINE OPERATING PARTNERSHIP, L.P.
Capitalized interest	$ 8,689	$ 4,650	$ 2,246

ORGANIZATION OF THE PARENT COMP

ORGANIZATION OF THE PARENT COMPANY AND THE OPERATING PARTNERSHIP	12 Months Ended
	Dec. 31, 2021
Organization, Consolidation and Presentation of Financial Statements [Abstract]
ORGANIZATION OF THE PARENT COMPANY AND THE OPERATING PARTNERSHIP	1. ORGANIZATION OF THE PARENT COMPANY AND THE OPERATING PARTNERSHIP Brandywine Realty Trust (the "Parent Company") is a self-administered and self-managed real estate investment trust (“REIT”) engaged in the acquisition, development, redevelopment, ownership, management, and operation of a portfolio of office and mixed-use properties. The Parent Company owns its assets and conducts its operations through Brandywine Operating Partnership, L.P. (the "Operating Partnership") and subsidiaries of the Operating Partnership. The Parent Company is the sole general partner of the Operating Partnership and, as of December 31, 2021, owned a 99.5% interest in the Operating Partnership. The Parent Company’s common shares of beneficial interest are publicly traded on the New York Stock Exchange under the ticker symbol “BDN.” The Parent Company, the Operating Partnership, and their consolidated subsidiaries are collectively referred to as the "Company." As of December 31, 2021, the Company owned 81 properties that contained an aggregate of approximately 13.7 million net rentable square feet (collectively, the “Properties”). The Company’s core portfolio of operating properties (the “Core Properties”) excludes development properties, redevelopment properties, and properties held for sale. The Properties were comprised of the following as of December 31, 2021: Number of Properties Rentable Square Feet Office properties 72 12,097,300 Mixed-use properties 5 942,334 Core Properties 77 13,039,634 Development property 1 205,803 Redevelopment properties 3 432,699 The Properties 81 13,678,136 In addition to the Properties, as of December 31, 2021, the Company owned 176.1 acres of land held for development, of which 10.0 acres were held for sale. The Company also held a leasehold interest in one land parcel totaling 0.8 acres, acquired through a prepaid 99-year ground lease, and held options to purchase approximately 55.5 additional acres of undeveloped land. As of December 31, 2021, the total potential development that this inventory of land could support under current zoning and entitlements, including the parcels under option, amounted to an estimated 13.4 million square feet, of which 0.1 million square feet relates to the 10.0 acres held for sale. As of December 31, 2021, the Company also owned economic interests in nine unconsolidated real estate ventures (see Note 4, ''Investment in Unconsolidated Real Estate Ventures ” for further information). The Properties and the properties owned by the unconsolidated real estate ventures are primarily located in or near Philadelphia, Pennsylvania; Austin, Texas; Metropolitan Washington, D.C.; Southern New Jersey; and Wilmington, Delaware. All references to building square footage, rentable square feet, acres, occupancy percentage, the number of buildings, and tax basis are unaudited. The Company conducts its third-party real estate management services business primarily through seven management companies (collectively, the “Management Companies”): Brandywine Realty Services Corporation (“BRSCO”), BDN Management Inc. (“BMI”), Brandywine Properties I Limited, Inc. (“BPI”), BDN Brokerage, LLC (“BBL”), Brandywine Properties Management, L.P. (“BPM”), Brandywine Brokerage Services, LLC (“BBS”), and BDN GC Services LLC ("BGCS"). Each of BRSCO, BMI and BPI is a taxable REIT subsidiary. BBS, BBL, BPM, and BGCS are tax disregarded entities wholly owned by the taxable REIT subsidiary entities. As of December 31, 2021, the Operating Partnership owned, directly and indirectly, 100% of each of BRSCO, BMI, BPI, BBL, BPM, BBS, and BGCS. As of December 31, 2021, the Management Company subsidiaries were managing properties containing an aggregate of approximately 23.1 million net rentable square feet, of which approximately 13.7 million net rentable square feet related to Properties owned by the Company and approximately 9.4 million net rentable square feet related to properties owned by third parties and unconsolidated real estate ventures.

SUMMARY OF SIGNIFICANT ACCOUNTI

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES	12 Months Ended
	Dec. 31, 2021
Accounting Policies [Abstract]
SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES	2. SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES Change in Depreciable Lives of Real Estate Investments In accordance with its policy, the Company reviews the estimated useful lives of its real estate investments on an ongoing basis. T he estimated useful lives of seven operating properties in Austin, Texas were modified to reflect the estimated periods during which these assets will remain in service pursuant to the Company's Uptown ATX master development plans. The estimated useful lives of these properties were decreased from approximately 35 years to approximately 12 years coinciding with the remaining terms of in-place leases. The effect of this change in estimate was a $9.8 million increase in depreciation expense during the year ended December 31, 2021. Principles of Consolidation The Company consolidates variable interest entities (“VIEs”) in which it is considered to be the primary beneficiary. VIEs are entities in which the equity investors do not have sufficient equity at risk to finance their endeavors without additional financial support or that the holders of the equity investment at risk do not have a controlling financial interest. The primary beneficiary is defined by the entity having both of the following characteristics: (i) the power to direct those matters that most significantly impact the activities of the VIE and (ii) the obligation to absorb losses or the right to receive benefits of the VIE that could potentially be significant to the VIE. For entities that the Company has the obligations to fund losses, its maximum exposure to loss is not limited to the carrying amount of its investments. The Company continuously assesses its determination of the primary beneficiary for each entity and assesses reconsideration events that may cause a change in the original determinations. As of December 31, 2021 and 2020, the Company included in its consolidated balance sheets consolidated VIEs having total assets of $46.5 million and $49.2 million, respectively, and total liabilities of $21.0 million and $21.6 million, respectively. When an entity is not deemed to be a VIE, the Company consolidates entities for which it has significant decision making control over the entity’s operations. The Company’s judgment with respect to its level of influence or control of an entity involves consideration of various factors including the form of the Company’s ownership interest, its representation in the entity’s governance, the size of its investment (including loans), estimates of future cash flows, its ability to participate in policy making decisions and the rights of the other investors to participate in the decision making process and to replace the Company as manager and/or liquidate the venture, if applicable. The Company’s assessment of its influence or control over an entity affects the presentation of these investments in the Company’s consolidated financial statements. In addition to evaluating control rights, the Company consolidates entities in which the outside partner has no substantive kick-out rights to remove the Company as managing member. The portion of the consolidated entities that are not owned by the Company is presented as noncontrolling interest as of and during the periods consolidated. All intercompany transactions have been eliminated in consolidation. Use of Estimates The preparation of financial statements in conformity with accounting principles generally accepted in the United States of America ("US GAAP") requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenue and expenses during the reporting period. Actual results could differ from those estimates. Operating Properties Operating properties are carried at historical cost less accumulated depreciation and impairment losses. The value of operating properties reflects their purchase price or development cost. Acquisition costs related to business combinations are expensed as incurred, whereas the costs related to asset acquisitions are capitalized as incurred. Costs incurred for the renovation and betterment of an operating property are capitalized to the Company’s investment in that property. Ordinary repairs and maintenance are expensed as incurred. Purchase Price Allocation For acquisitions of real estate or in-substance real estate that are accounted for as business combinations, we recognize the assets acquired (including the intangible value of acquired above- or below-market leases, acquired in-place leases and tenant relationship values), liabilities assumed, noncontrolling interests, and previously existing ownership interests at fair value as of the acquisition date. Any excess (deficit) of the consideration transferred relative to the fair value of the net assets acquired is accounted for as goodwill (bargain purchase gain). Acquisition costs related to business combinations are expensed as incurred. Acquisitions of real estate and in-substance real estate that do not meet the definition of a business are accounted for as asset acquisitions. The Company generally expects that acquisitions of real estate or in-substance real estate will not meet the definition of business and therefore are accounted for as asset acquisitions, unless specifically noted otherwise. The accounting model for asset acquisitions is similar to the accounting model for business combinations except that the acquisition consideration (including acquisition costs) is allocated to the individual assets acquired and liabilities assumed on a relative fair value basis. As a result, asset acquisitions do not result in recognition of goodwill or a bargain purchase gain. Additionally, because the accounting model for asset acquisitions is a cost accumulation model, preexisting interests in the acquired assets, if any, are not remeasured to fair value but continue to be accounted for at their historical cost. Direct acquisition costs are capitalized if an asset acquisition is probable. If we determine that an asset acquisition is no longer probable, no new costs are capitalized and all capitalized costs that are not recoverable are written off. The purchase price is allocated to the acquired assets and assumed liabilities, including land and buildings, as if vacant based on highest and best use for the acquired assets. The Company assesses and considers fair value of the operating properties based on estimated cash flow projections that utilize discount and/or capitalization rates that it deems appropriate, as well as available market information. Estimates of future cash flows are based on a number of factors including the historical operating results, known and anticipated trends, and market and economic conditions. The Company allocates the purchase price of properties considered to be business combinations and asset acquisitions to net tangible and identified intangible assets acquired based on fair values. Above-market and below-market in-place lease values for acquired properties are recorded based on the present value (using an interest rate which reflects the risks associated with the leases acquired) of the difference between (i) the contractual amounts to be paid pursuant to the in-place leases and (ii) the Company’s estimate of the fair market lease rates for the corresponding in-place leases, measured over a period equal to the remaining noncancellable term of the lease (including the below market fixed renewal periods that are considered probable, if applicable). Capitalized above-market lease values are amortized as a reduction of rental income over the remaining noncancellable terms of the respective leases. Capitalized below-market lease values are amortized as an increase to rental income over the remaining noncancellable terms of the respective leases, including any below market fixed-rate renewal option periods that are considered probable. Other intangible assets also include in-place leases based on the Company’s evaluation of the specific characteristics of each tenant’s lease and the Company’s overall relationship with the respective tenant. The Company estimates the cost to execute leases with terms similar to the remaining lease terms of the in-place leases, including leasing commissions, legal and other related expenses. This intangible asset is amortized to expense over the remaining term of the respective leases and any fixed-rate bargain renewal periods. Factors considered by the Company in this analysis include an estimate of the carrying costs during the expected lease-up periods considering current market conditions and costs to execute similar leases. In estimating carrying costs, the Company includes real estate taxes, insurance, and other operating expenses, and estimates of lost rents at market rates during the expected lease-up periods, which primarily range from four In the event that a tenant terminates its lease, the unamortized portion of each intangible, including in-place lease values and tenant relationship values, is charged to expense and market rate adjustments (above or below) are recorded to revenue. Depreciation and Amortization The costs of buildings and improvements are depreciated using the straight-line method based on the following useful lives: buildings and improvements (5 to 55 years) and tenant improvements (the shorter of (i) the life of the asset (1 to 16 years) or (ii) the lease term). Construction-in-Progress Project costs directly associated with the development or redevelopment and construction of a real estate project are capitalized as construction-in-progress. Construction-in-progress also includes costs related to ongoing tenant improvement projects. In addition, interest, real estate taxes, and other expenses that are directly associated with the Company’s development or redevelopment activities are capitalized beginning when activities necessary to ready the asset for its intended use are in progress and capital expenditures have been made and ending when the property is placed in service. Interest expense is capitalized using the Company’s weighted average interest rate. Internal direct costs are capitalized to projects in which qualifying expenditures are being incurred. See Note 3, ''Real Estate Investments," for more information related to the capitalization of project costs. Ground Leases The Company is the lessee under long-term ground leases classified as operating leases. The Company makes significant assumptions and judgments when determining the discount rate for the lease to calculate the present value of the lease payments. As the rate implicit in the lease is not readily determinable, the Company estimates the incremental borrowing rate (“IBR”) that it would need to pay to borrow, on a collateralized basis, an amount equal to the lease payments in a similar economic environment, over a similar lease term. The Company utilizes a market-based approach to estimate the IBR for each individual lease. The base IBR is estimated utilizing observable mortgage and corporate bond rates, which are then adjusted to account for considerations related to the Company’s credit rating and the lease term to select an incremental borrowing rate for each lease. The right of use assets and lease liabilities are presented as “Right of use asset - operating leases, net” and “Lease liability - operating leases”, respectively, on the consolidated balance sheet as of December 31, 2021 and 2020, respectively. The lease liabilities and right of use assets are amortized on a straight-line basis over the lease term with the corresponding expense classified in “Property operating expenses” on the consolidated statements of operations. The most recent CPI adjustment is used to determine the present value of the lease payments for an indexed lease and ultimately the right of use asset and corresponding lease liability. Rent payments for amounts in excess of this estimated growth rate will be expensed on a cash basis as incurred and are considered variable lease costs. Impairment of Real Estate Investments The Company reviews its real estate investments for impairment following the end of each quarter for each of its real estate investments where events or changes in circumstances indicate that the carrying amounts may not be recoverable. The Company updates leasing and other assumptions regularly, paying particular attention to real estate investments where there is an event or change in circumstances that indicates an impairment in value. Additionally, the Company considers strategic decisions regarding the future development plans for real estate investment under development and other market factors. For real estate investments to be held and used, the Company analyzes recoverability based on the estimated undiscounted future cash flows expected to be generated from the operations and eventual disposition of the assets over, in most cases, a 10-year hold period. If there is significant possibility that the Company will dispose of assets earlier, it analyzes the recoverability using a probability weighted analysis of the undiscounted future cash flows expected to be generated from the operations and eventual disposition of each asset using various probable hold periods. If the recoverability analysis indicates that the carrying value of the tested real estate investment is not recoverable, the real estate investment is written down to its fair value and an impairment is recognized in the amount of the excess of the carrying amount of the asset over its fair value. If and when the Company’s plans change, it revises its recoverability analysis to use cash flows expected from operations and eventual disposition of each asset using hold periods that are consistent with its revised plans. Estimated future cash flows used in such analysis are based on the Company’s plans for the real estate investment and its views of market economic conditions. The estimates consider assumptions, including but not limited to market rental rates, capitalization rates, and recent sales data for comparable real estate investments. Future cash flows are discounted when determining fair value of an asset. Most of these assumptions are influenced by our direct experience with the real estate investments and their markets as well as market data obtained from real estate leasing and brokerage firms. Assets Held for Sale The Company generally reclassifies assets to held for sale when the transaction has been approved by its Board of Trustees, or by officers vested with authority to approve the transaction, and there are no known significant contingencies relating to the sale of the real estate investment within one year of the consideration date and the consummation of the transaction is otherwise considered probable. When a real estate investment is designated as held for sale, the Company stops depreciating the real estate investment and estimates the real estate investment’s fair value, net of selling costs. If the determination is made that the estimated fair value, net of selling costs, is less than the net carrying value of the real estate investment, an impairment is recognized, reducing the net carrying value of the real estate investment to estimated fair value less selling costs. For periods in which a real estate investment is classified as held for sale, the Company classifies the assets and liabilities, as applicable, of the real estate investment as held for sale on the consolidated balance sheet for such periods. Impairment of Land Held for Development When demand for build-to-suit properties declines and the ability to sell land held for development deteriorates, or other market factors indicate possible impairment in the recoverability of land held for development, it is reviewed for impairment by comparing its fair value to its carrying value. If the estimated sales value is less than the carrying value, the carrying value is written down to its estimated fair value. Estimated fair value is generally determined using a market valuation approach, comparing the subject property to recent comparable market transactions in a similar location; or using estimated cash flows. Cash and Cash Equivalents Cash and cash equivalents are highly-liquid investments with original maturities of three months or less. The Company maintains cash equivalents in money market accounts with financial institutions in excess of insured limits, but believes this risk is mitigated by only investing in or through major financial institutions. The Company does not invest its available cash balances in money market funds. As such, available cash balances are appropriately reflected as cash and cash equivalents on the consolidated balance sheets. Restricted Cash Restricted cash consists of cash held as collateral to provide credit enhancement for the Company’s mortgage debt, cash for property taxes, capital expenditures and tenant improvements. Restricted cash also includes cash held by qualified intermediaries for possible investments in like-kind exchanges in accordance with Section 1031 of the Internal Revenue Code in connection with sales of the Company’s properties. Restricted cash is included in “Other assets” in the consolidated balance sheets. Accounts Receivable and Accrued Rent Receivable Generally, leases with tenants are accounted for as operating leases. Minimum lease payments under tenant leases are recognized on a straight-line basis over the term of the related lease. The cumulative difference between lease revenue recognized under the straight-line method and contractual lease payment terms are recorded as “Accrued rent receivable, net” on the consolidated balance sheets. Included in current tenant receivables are tenant reimbursements which are comprised of amounts recoverable from tenants for common area maintenance expenses and certain other recoverable expenses that are recognized as revenue in the period in which the related expenses are incurred. Accrued rent receivables are carried net of the allowances for doubtful accounts. The allowance for doubtful accounts is an estimate based on the Company's experience of the probability of future events confirming a loss and represents the estimated probable losses. The allowance is generally calculated by assigning risk factors by industry which are primarily based on the Company's historical collection and charge-off experience adjusted for current market conditions, which requires management's judgment. Investments in Unconsolidated Real Estate Ventures Under the equity method, investments in real estate ventures are recorded initially at cost and subsequently adjusted for equity in earnings, contributions, distributions, and impairments. The Company generally allocates income and losses from the unconsolidated real estate ventures based on the venture's distribution priorities, which may be different from its stated ownership percentage. For real estate ventures that are constructing assets to commence planned principal operations, the Company capitalizes interest expense to the extent that it is recoverable using the Company’s weighted average interest rate of consolidated debt and its investment balance as a basis. Planned principal operations commence when a property is available to lease and at that point in time, the Company ceases capitalizing interest to its investment basis. At least quarterly, management assesses whether there are any other than temporary impairment indicators of the Company’s investments in real estate ventures. An investment is other than temporarily impaired only if the fair value of the investment in a real estate venture, as estimated by management, is less than the carrying value and the decline is other than temporary. To the extent that an other than temporary impairment has occurred, an impairment charge is recorded in the amount of the excess of the carrying amount of the investment over the estimated fair value. Management is required to make significant judgments about the estimated fair value of its investments to determine if an impairment exists. Fair value is generally determined through income valuation approaches, including discounted cash flows and direct capitalization models. When the Company acquires an interest in or contributes assets to a real estate venture project, the difference between the Company’s cost basis in the investment and the value of the real estate venture or asset contributed is amortized over the life of the related assets, intangibles, and liabilities and such adjustment is included in the Company’s share of equity in income of unconsolidated real estate ventures. Deferred Costs Certain costs incurred in connection with property leasing are capitalized as deferred leasing costs. Deferred leasing costs consist primarily of third-party and internal leasing commissions that are amortized using the straight-line method over the life of the respective lease which generally ranges from 1 to 16 years. Management re-evaluates the remaining useful lives of leasing costs in conjunction with changes in the respective lease term. Notes Receivable The Company accounts for notes receivable on its balance sheet at amortized cost, net of allowance for loan losses. Interest income is recognized over the term of the notes receivable and is calculated based on the contractual terms of each note agreement. At inception and on a quarterly basis, the Company evaluates notes receivable for the current estimate of expected credit losses over the contractual term using a probability-of-default method and reports in net income (as a credit loss expense) the amount necessary to adjust the allowance for credit losses to reflect management's current estimate. Management considers performance and/or value of the underlying collateral property as well as the financial and operating capability of the borrower/sponsor in its evaluation. Notes receivable are placed on nonaccrual status when management determines, after considering economic and business conditions and collection efforts, that the loans are impaired, or collection of interest is doubtful. Uncollectible interest previously accrued is recognized as bad debt expense. Interest income on nonaccrual loans is recognized only to the extent that cash payments are received. Deferred Financing Costs Costs incurred in connection with debt financing are capitalized as a direct deduction from the carrying value of the debt, except for costs capitalized related to the Company’s unsecured credit facility, which are capitalized within the “Deferred costs, net” caption on the accompanying consolidated balance sheets. Deferred financing costs are charged to interest expense over the terms of the related debt agreements. Deferred financing costs consist primarily of loan fees which are amortized over the related loan term on a basis that approximates the effective interest method. Deferred financing costs are accelerated, when debt is extinguished, as part of the “Interest expense-amortization of deferred financing costs” caption within the Company’s consolidated statements of operations. Original issue discounts are recognized as part of the gain or loss on extinguishment of debt, as appropriate. Revenue Recognition Rental Revenue The Company generates revenue under leases with tenants occupying the Properties. Generally, leases with tenants are accounted for as operating leases. The operating leases have various expiration dates. As of December 31, 2021 and 2020, the Company did not have any leases classified as direct-financing or sales-type leases. Fixed lease payments under tenant leases, determined to be collectible, are recognized on a straight-line basis over the term of the related lease. The cumulative difference between lease revenue recognized under the straight-line method and contractual lease payments are recorded as “Accrued rent receivable” on the consolidated balance sheets. Variable lease payments are recognized as lease revenue in the period in which changes occur in facts and circumstances on which the variable lease payments are based. Topic 842 requires a binary approach to evaluating leases for collectability. Lessors are required to determine if it is probable that substantially all of the lease payments will be collected from the tenant over the lease term. Should the lessor determine that it is not probable that substantially all of the lease payments will be collected, the standard requires that the lessor write off any accrued rent receivable and begin recognizing lease payments on a cash basis. The Company’s lease revenue is impacted by the Company’s determination of whether improvements to the property, whether made by the Company or by the tenant, are landlord assets. The determination of whether an improvement is a landlord asset requires judgment. In making this judgment, the Company’s primary consideration is whether an improvement would be utilizable by another tenant upon the then-existing tenant vacating the improved space. If the Company has funded an improvement that it determines not to be landlord assets, then it treats the cost of the improvement as a lease incentive. If the tenant has funded an improvement that the Company determines to be landlord assets, then the Company treats the costs of the improvement as deferred revenue and amortizes these costs into revenue over the lease term. For certain leases, the Company also makes significant assumptions and judgments in determining the lease term, including assumptions when the lease provides the tenant with an early termination option or purchase option. The lease term impacts the period over which the Company determines and records lease payments and also impacts the period over which it amortizes lease-related costs. The Company considers all relevant factors that create an economic incentive for the lessee and uses judgment to determine if those factors, considered together, signify that the lessee is reasonably certain to exercise the option. For leases where a tenant executes a lease termination, termination fees are generally recognized over the modified term of the lease as rental income. Additionally, any deferred rents receivable are accelerated over the modified lease term. The Company’s leases also typically provide for tenant reimbursement of a portion of common area maintenance expenses and other operating expenses to the extent that a tenant’s pro rata share of expenses exceeds a base year level set in the lease or to the extent that the tenant has a lease on a triple net basis. As the timing and pattern of revenue recognition is the same, rents and tenant reimbursements are treated as a combined lease component and included in the "Rents" caption within the Company's consolidated statements of operations. Fixed lease payments include contractual rents under lease agreements with tenants recognized on a straight-line basis over the lease term, including amortization of lease incentives and above or below market rent intangibles, and parking income that is fixed under a long-term contract. Variable lease payments include reimbursements billed to tenants, termination fees, bad debt expense, and parking income that is not fixed under a long-term contract. Point of Sale Revenue Point of sale revenue consists of parking, restaurant, and flexible stay revenue from the Company’s hotel operations. Point of sale service obligations are performed daily, and the customer obtains control of those services simultaneously as they are performed. Accordingly, revenue is recorded on an accrual basis as it is earned, coinciding with the services that are provided to the Company’s customers. Parking and flexible stay revenue is recognized within rents and restaurant income is recognized within other income on the consolidated statements of operations. Third party management fees, labor reimbursement, and leasing The Company performs property management services for its managed real estate ventures and third-party property owners of real estate that consist of: (i) providing leasing services, (ii) property inspections, (iii) repairs and maintenance monitoring, and (iv) financial and accounting oversight. For these services, the Company earns management fees monthly, which are based on a fixed percentage of each managed property’s financial results, and is reimbursed for the labor costs incurred by its property management employees as services are rendered to the property owners. The Company determined that control over the services is passed to its customers simultaneously as performance occurs. Accordingly, management fee revenue is earned as the services are provided to the Company’s customers. Lease commissions are earned when the Company, as a broker for the third party property owner, executes a lease agreement with a tenant. Based on the terms of the Company’s lease commission contracts, the Company's performance obligation to the customer has been completed upon execution of each lease agreement. The Company’s lease commissions are earned based on a fixed percentage of rental income generated for each executed lease agreement and there is no variable income component. Development fee revenue is earned through two different sources: (i) the Company performs development services for third parties as an agent and earns fixed development fees based on a percentage of construction costs incurred over the construction period, and (ii) the Company acts as a general contractor on behalf of one of its managed real estate ventures. The Company acts as the principal construction company for the real estate ventures and records gross revenue as it provides construction services based on the quantifiable construction outputs. In applying the cost based output method of revenue recognition, the Company uses the actual costs incurred relative to the total estimated costs to determine its progress towards contract completion and to calculate the corresponding gross revenue and gross profit to recognize. For any costs that do not contribute to satisfying the Company’s performance obligations, it excludes such costs from its output methods of revenue recognition as the amounts are not reflective of transferring control of the outputs to the customer. The use of estimates in this calculation involves significant judgment. The following is a summary of revenue earned by the Company’s reportable segments (see Note 19, ''Segment Information,” for further information) during the year ended December 31, 2021 (in thousands): Philadelphia CBD Pennsylvania Suburbs Austin, Texas Metropolitan Washington, D.C. Other Corporate (a) Total Fixed rent $ 149,441 $ 113,748 $ 62,545 $ 12,410 $ 8,020 $ (2,240) $ 343,924 Variable rent 41,585 10,358 34,850 646 2,660 (257) 89,842 Total lease revenue 191,026 124,106 97,395 13,056 10,680 (2,497) 433,766 Amortization of deferred market rents 2,064 (9) 3,322 — — — 5,377 Daily parking & hotel flexible stay 11,758 159 109 117 233 — 12,376 Total rents 204,848 124,256 100,826 13,173 10,913 (2,497) 451,519 Third party management fees, labor reimbursement and leasing 893 34 452 6,548 3,077 15,440 26,444 Other income 2,117 276 402 144 25 5,892 8,856 Total revenue $ 207,858 $ 124,566 $ 101,680 $ 19,865 $ 14,015 $ 18,835 $ 486,819 The following is a summary of revenue earned by the Company’s reportable segments (see Note 19, ''Segment Information,” for further information) during the year ended December 31, 2020 (in thousands): Philadelphia CBD Pennsylvania Suburbs Austin, Texas Metropolitan Washington, D.C. Other Corporate (a) Total Fixed rent $ 166,286 $ 128,044 $ 63,366 $ 29,830 $ 8,064 $ (2,412) $ 393,178 Variable rent 51,410 12,951 35,123 3,544 2,401 (1,343) 104,086 Total lease revenue 217,696 140,995 98,489 33,374 10,465 (3,755) 497,264 Amortization of deferred market rents 1,146 (12) 3,531 — 203 — 4,868 Daily parking & hotel flexible stay 10,777 179 49 135 232 — 11,372 Total rents 229,619 141,162 102,069 33,509 10,900 (3,755) 513,504 Third party management fees, labor reimbursement and leasing 927 39 689 6,541 2,560 7,824 18,580 Other income 1,482 412 224 173 9 468 2,768 Total revenue $ 232,028 $ 141,613 $ 102,982 $ 40,223 $ 13,469 $ 4,537 $ 534,852 The following is a summary of revenue earned by the Company’s reportable segments (see Note 19, ''Segment Information,” for further information) during the year ended December 31, 2019 (in thousands): Philadelphia CBD Pennsylvania Suburbs Austin, Texas Metropolitan Washington, D.C. Other Corporate

REAL ESTATE INVESTMENTS

REAL ESTATE INVESTMENTS	12 Months Ended
	Dec. 31, 2021
Real Estate [Abstract]
REAL ESTATE INVESTMENTS	3. REAL ESTATE INVESTMENTS As of December 31, 2021 and 2020, the gross carrying value of the operating properties was as follows (in thousands): December 31, 2021 December 31, 2020 Land $ 410,144 $ 407,514 Building and improvements 2,653,492 2,665,232 Tenant improvements 408,966 401,363 Total $ 3,472,602 $ 3,474,109 Construction-in-Progress Internal direct construction costs totaling $7.9 million in 2021, $8.4 million in 2020, and $7.4 million in 2019 and interest totaling $7.0 million in 2021, $4.6 million in 2020, and $3.2 million in 2019 were capitalized related to the development, redevelopment and construction of tenant improvements of certain properties and land holdings. During the years ended December 31, 2021, 2020 and 2019, the Company’s internal direct construction costs are comprised entirely of capitalized salaries. The following table shows the amount of compensation costs (including bonuses and benefits) capitalized for the years presented (in thousands): December 31, 2021 2020 2019 Development $ 4,815 $ 4,802 $ 3,047 Redevelopment 1,170 543 775 Tenant Improvements 1,917 3,021 3,609 Total $ 7,902 $ 8,366 $ 7,431 2021 Acquisitions During the year ended December 31, 2021, the Company did not acquire any properties from a third party. 2020 Acquisitions The following table summarizes the property acquisitions during the year ended December 31, 2020 (dollars in thousands): Property/Portfolio Name Acquisition Date Location Property Type Rentable Square Feet/Acres Purchase Price (a) 145 King of Prussia Road February 27, 2020 Radnor, PA Land 7.75 acres $ 11,250 1505-11 Race Street November 5, 2020 Philadelphia, PA Office 119,763 $ 9,700 250 King of Prussia Road (b) November 30, 2020 Radnor, PA Office 169,843 $ 20,250 (a) Exclusive of transaction costs and price adjustments. See purchase price allocation table below for a breakout of the net purchase price for wholly owned properties. (b) This property was placed into redevelopment and is therefore included within Construction-in-progress on the consolidated balance sheets. The Company accounted for the acquisition of 1501-11 Race Street as an asset acquisition and therefore capitalized $0.3 million of acquisition related costs. The Company utilized a number of sources in making estimates of fair value (including comparative sales transactions and market leasing assumptions) for purposes of allocating the purchase price to tangible and intangible assets acquired The acquisition values have been allocated as follows (in thousands): 1505-11 Race Street Building, land and improvements $ 9,723 Intangible assets acquired 2,422 Below market lease liabilities assumed (2,193) Total unencumbered acquisition value 9,952 Amortization period of intangible assets 1.5 years Amortization period of below market liabilities assumed 1.5 years 2019 Acquisitions During the year ended December 31, 2019, the Company did not acquire any properties from a third party. Dispositions The following table summarizes the property dispositions during the years ended December 31, 2021, 2020 and 2019 (dollars in thousands): Property/Portfolio Name Disposition Date Location Property Type Rentable Square Feet/Acres Sales Price Gain/(Loss) on Sale (a) 1100 Lenox Drive September 8, 2021 Lawrenceville, NJ Land 5.0 acres $ 2,575 $ 68 2100-2200 Lenox Drive July 6, 2021 Lawrenceville, NJ Land 35.2 acres $ 8,900 $ 842 Mid-Atlantic Office Portfolio (b) (d) December 21, 2020 Various Office 1,128,645 $ 192,943 $ 15,164 One and Two Commerce Square (c) July 21, 2020 Philadelphia, PA Office 1,896,142 $ 115,000 $ 271,905 Keith Valley June 15, 2020 Horsham, PA Land 14.0 Acres $ 4,000 $ 201 52 East Swedesford Road March 19, 2020 Malvern, PA Office 131,077 $ 18,000 $ 2,336 1900 Gallows Rd September 11, 2019 Vienna, VA Office 210,632 $ 36,400 $ (367) 9 Presidential Boulevard March 15, 2019 Bala Cynwyd, PA Land 2.7 Acres $ 5,325 $ 751 (a) Gain/(Loss) on Sale is net of closing and other transaction related costs. (b) The Company sold a 60% equity interest in a portfolio of twelve suburban office properties containing an aggregate of 1.1 million square feet ("Mid-Atlantic Office Portfolio"), nine of which are located in the Pennsylvania suburbs and three of which are located in Maryland, to an unrelated third party for a gross sales price of $192.9 million. The transaction resulted in deconsolidation of the properties and formation of PA/MD NNN Office JV, LLC ("Mid-Atlantic Office JV"). The Company recorded its investment at fair value and recognized a gain of $15.2 million in "Net gain on disposition of real estate" on the consolidated statements of operations. See Note 4, ''Investment in Unconsolidated Real Estate Ventures," for further information. (c) The Company sold a 30% preferred equity interest in two office buildings located in Philadelphia, Pennsylvania, to an unrelated third party for $115.0 million (the "Commerce Square Venture Transaction"), which resulted in deconsolidation of the properties and formation of Brandywine Commerce I LP and Brandywine Commerce II LP (collectively, the "Commerce Square Venture"). The transaction valued the properties at $600.0 million. The Company recorded its investment at fair value and recognized a gain of $271.9 million in "Net gain on disposition of real estate" on the consolidated statements of operations. See Note 4, ''Investment in Unconsolidated Real Estate Ventures," for further information. (d) The sales price includes $4.1 million of variable consideration held in escrow that will be released to the Company over a six In addition, on February 2, 2021, the Company contributed its investment in a 99-year prepaid leasehold interest in a one-acre land parcel held for development at 3025 JFK Boulevard in Philadelphia, Pennsylvania to a newly formed joint venture with an unaffiliated third party. The project is part of the Schuylkill Yards master development. The Company's investment in the project was valued at $34.8 million and the transaction resulted in deconsolidation of the property and conversion of Brandywine Opportunity Fund, L.P. (formerly a wholly-owned subsidiary of the Operating Partnership) to a real estate venture ("3025 JFK Venture"). The Company recorded its investment at fair value and recognized a gain of $2.0 million in "Net gain on sale of undepreciated real estate" on the consolidated statements of operations. See Note 4, "Investment in Unconsolidated Real Estate Ventures," for further information. During the year ended December 31, 2019, the Company also recorded a $1.0 million gain related to contingent consideration received related to a land sale that closed in a prior period in the Other segment. The Company also received additional proceeds from a sale that closed in a prior year related to a property in the Metropolitan Washington, D.C. segment resulting in $0.7 million of additional gain on sale. One Uptown Venture On December 1, 2021, the Company entered into two joint venture agreements with affiliates of Canyon Partners Real Estate to commence development of One Uptown, a $328.4 million mixed-used project in Austin, Texas. One Uptown has been designed to deliver 348,000 square feet of Class-A workspace and 15,000 square feet of street-level retail (through the "office" joint venture) and 341 apartment residences and a public park (through the "multifamily" joint venture) and a six-story parking garage to be shared by the two joint ventures. The Company's partner in each of the two joint ventures has agreed, subject to customary funding conditions, including closing of the applicable construction loan, to fund approximately $57.5 million of the combined project costs in exchange for a 50% preferred equity interest in each of the two joint ventures, with the Company retaining a 50% common equity interest in each. The Company is in the process of securing a construction loan for each of the two joint ventures that would total approximately $213.4 million, representing 65% of the combined project costs. Under the terms of each of the joint venture agreements, the joint venture partner has no obligation to fund any portion of the applicable project costs until the closing of the applicable construction loan. This right prevents the Company from meeting the sale recognition criteria of ASC 606 until the applicable closings of the construction loans. Held for Use Impairment As of December 31, 2021, 2020, and 2019, the Company evaluated the recoverability of the carrying value of its properties that triggered assessment. Based on the analysis, no impairments were identified during the twelve months ended December 31, 2021, 2020, and 2019. Held for Sale As of December 31, 2021, the Company determined that the sale of two adjacent parcels of land within the Other segment totaling 10.0 acres was probable and classified these properties as held for sale. As such, $0.6 million was classified as “Assets held for sale, net” on the consolidated balance sheets. The Company closed on the sale of the two parcels of land on January 20, 2022 for an aggregate sales price of $1.6 million.

INVESTMENT IN UNCONSOLIDATED RE

INVESTMENT IN UNCONSOLIDATED REAL ESTATE VENTURES	12 Months Ended
	Dec. 31, 2021
Equity Method Investments and Joint Ventures [Abstract]
INVESTMENT IN UNCONSOLIDATED REAL ESTATE VENTURES	4. INVESTMENT IN UNCONSOLIDATED REAL ESTATE VENTURES As of December 31, 2021, the Company held ownership interests in nine unconsolidated real estate ventures for a net aggregate investment balance of $411.1 million, which includes a negative investment balance in one unconsolidated real estate venture of $24.4 million, reflected within "Other liabilities" on the consolidated balance sheets. As of December 31, 2021, four of the real estate ventures owned properties that contained an aggregate of approximately 8.2 million net rentable square feet of office space; two real estate ventures owned 1.4 acres of land held for development; one real estate venture owned 1.0 acres of land in active development; one real estate venture owned a mixed used tower comprised of 250 apartment units and 0.2 million net rentable square feet of office/retail space; and one real estate venture owned a residential tower that contained 321 apartment units. The Company accounts for its interests in the unconsolidated real estate ventures, which range from 15% to 70%, using the equity method. Certain of the unconsolidated real estate ventures are subject to specified priority allocations of distributable cash. The Company earned management fees from the unconsolidated real estate ventures of $8.1 million, $4.7 million and $4.3 million for the years ended December 31, 2021, 2020 and 2019, respectively. The Company earned leasing commissions from the unconsolidated real estate ventures of $3.8 million, $1.1 million and $1.7 million for the years ended December 31, 2021, 2020 and 2019, respectively. The Company had outstanding accounts receivable balances from the unconsolidated real estate ventures of $2.5 million and $1.2 million as of December 31, 2021 and 2020, respectively. The amounts reflected in the following tables (except for the Company’s share of equity in income) are based on the financial information of the individual unconsolidated real estate ventures. The Company records operating losses of a real estate venture in excess of its investment balance if the Company is liable for the obligations of the real estate venture or is otherwise committed to provide financial support to the real estate venture. The Company’s investment in the unconsolidated real estate ventures as of December 31, 2021 and 2020, and the Company’s share of the unconsolidated real estate ventures’ income (loss) for the years ended December 31, 2021 and 2020 was as follows (in thousands): Ownership Percentage Carrying Amount Company's Share of unconsolidated real estate venture Income (Loss) Unconsolidated Real Estate Venture Debt at 100%, gross 2021 2020 2021 2020 2019 2021 2020 Office Properties Commerce Square Venture 70% (a) $ 247,798 $ 253,128 $ (15,501) $ (9,150) — $ 213,069 $ 219,168 Mid-Atlantic Office Venture 40% (a) 31,680 32,996 932 96 — 123,015 120,831 Brandywine - AI Venture LLC 50% — 10,302 (721) 185 (2,800) — — Herndon Innovation Center Metro Portfolio Venture, LLC 15% 15,844 16,019 (174) (358) (498) 207,302 207,302 MAP Venture 50% (24,396) (11,516) (8,683) (6,570) (6,102) 184,263 185,000 PJP VII 25% (b) — — — — 190 — — PJP II 30% (b) — — — — 81 — — PJP VI 25% (b) — — — — (185) — — Other 4040 Wilson Venture (c) 50% 31,059 34,454 (2,258) (2,162) (368) 145,000 141,857 1919 Venture 50% 13,791 15,434 427 59 328 88,860 88,860 Development Properties 3025 JFK Venture 55% 56,370 — (118) — — — — JBG - 51 N Street (c) 70% 21,213 21,237 (402) (457) (313) — — JBG - 1250 First Street Office (c) 70% 17,751 17,757 (199) (227) (255) — — $ 411,110 $ 389,811 $ (26,697) $ (18,584) (9,922) $ 961,509 $ 963,018 (a) Ownership percentage represents the Company’s combined interest including preferred and common equity holdings. See "Commerce Square Venture" and "Mid-Atlantic Office JV" sections below for more information. (b) On October 29, 2019, the Company sold its interest in PJP II, PJP VI and PJP VII. See "PJP Ventures" section below for more information on the disposal. (c) This entity is a VIE. The following is a summary of the financial position of the unconsolidated real estate ventures in which the Company held interests as of December 31, 2021 and December 31, 2020 (in thousands): December 31, 2021 December 31, 2020 Net property $ 1,563,263 $ 1,520,804 Other assets 434,687 488,805 Other liabilities 331,947 333,049 Debt, net 956,668 956,688 Equity (a) 709,335 719,872 (a) This amount does not include the effect of the basis difference between the Company's historical cost basis and the basis recorded at the real estate venture level, which is typically amortized over the life of the related assets and liabilities. Basis differentials occur from the impairment of investments, purchases of third party interests in existing real estate ventures and upon the transfer of assets that were previously owned by the Company into a real estate venture. In addition, certain acquisition, transaction and other costs may not be reflected in the net assets at the real estate venture level. The following is a summary of results of operations of the unconsolidated real estate ventures in which the Company held interests during the twelve-month periods ended December 31, 2021, 2020 and 2019 (in thousands): Year Ended December 31, 2021 2020 2019 Revenue $ 214,792 $ 150,276 $ 132,358 Operating expenses (117,273) (85,812) (71,784) Interest expense, net (30,569) (22,661) (21,908) Depreciation and amortization (97,147) (70,805) (53,331) Provision for impairment (1,393) — (5,664) Loss on early extinguishment of debt — — (1,231) Net loss $ (31,590) $ (29,002) $ (21,560) Ownership interest % Various Various Various Company's share of net loss $ (25,972) $ (18,540) $ (9,865) Basis adjustments and other (725) (44) (57) Equity in loss of unconsolidated real estate ventures $ (26,697) $ (18,584) $ (9,922) As of December 31, 2021, the aggregate principal payments of the unconsolidated real estate ventures recourse and non-recourse debt payable to third-parties are as follows (in thousands): 2022 $ 8,543 2023 477,649 2024 330,317 2025 — 2026 145,000 Thereafter — Total principal payments 961,509 Net deferred financing costs (5,923) Net original issue premium 1,082 Outstanding indebtedness $ 956,668 4040 Wilson Venture The 4040 Wilson LLC Venture (“4040 Wilson”) consists of one property containing an aggregate of 225,000 square feet of office/retail and 250 apartment units, located in the Metropolitan Washington, D.C. segment. The Company and its partner each own a 50% interest in 4040 Wilson. The residential component and office/retail portion of 4040 Wilson were substantially complete and placed into service during the first quarter of 2020 and the first quarter of 2021, respectively. During the fourth quarter of 2021, 4040 Wilson refinanced the $150.0 million secured construction loan into a $155.0 million mortgage loan secured by the property. The interest rate on this loan is 1.8% over term SOFR and matures in December 2026. Brandywine - AI Venture During the year ended December 31, 2021, Brandywine - AI Venture, recorded a $1.4 million held for sale impairment charge related to 3141 Fairview Park Drive. The Company’s share of the impairment charge was $0.7 million, which is reflected in “Equity in loss of Real Estate Ventures” in the consolidated statements of operations for the year ended December 31, 2021. The impairment was measured based on an executed sale agreement with a third-party. The Company determined that its investment in the real estate venture is not impaired as the Company's share of the distributable cash is in excess of the Company's basis in the real estate venture. On November 9, 2021, BDN AI Venture sold 3141 Fairview Park Drive, the last remaining office property, totaling 183,618 rentable square feet in Falls Church, Virginia, at an aggregate sales price of $27.6 million. The Company received cash proceeds of $12.6 million after closing costs. The Company recorded an $3.0 million gain within the caption "Net gain on real estate venture transactions" within its consolidated statements of operations for the year ended December 31, 2021 upon liquidation of the venture. During 2019, BDN - AI Venture recorded a $5.6 million held for use impairment charge related to 3141 Fairview Park Drive. The Company’s share of the impairment charge was $2.8 million which is reflected in “Equity in loss of unconsolidated real estate ventures” in the consolidated statements of operations for the year ended December 31, 2019. The impairment was measured based on an appraisal of the property performed by a third party. The Company determined that its investment in the real estate venture was not impaired as the Company's share of the distributable cash was in excess of the Company's basis in the real estate venture. During 2019, BDN - AI Venture transferred an office building located in Falls Church, Virginia containing 180,659 rentable square feet to the mortgage lender in full satisfaction of the lender’s outstanding $26.0 million mortgage loan. The mortgage loan was nonrecourse to the Company. The Company recognized its $2.2 million share of the gain on debt forgiveness in "Net gain on real estate venture transactions" in the consolidated statements of operations for the year ended December 31, 2019. 3025 JFK Venture On February 2, 2021, the Company contributed its investment in a 99-year prepaid leasehold interest in a one-acre land parcel held for development at 3025 JFK Boulevard in Philadelphia, Pennsylvania to the 3025 JFK Venture. The Company's initial investment in this real estate venture at February 2, 2021 was $34.8 million. The real estate venture was formed to develop a 570,000 square foot mixed-use building at property under the long-term ground lease. The estimated project cost is approximately $287.3 million, and the joint venture partner has agreed, subject to customary funding conditions, to fund up to approximately $45.2 million of the project costs in exchange for a 45% preferred equity interest in the venture and the Company will retain a 55% preferred equity interest. On July 23, 2021, the 3025 JFK Venture closed on a $186.7 million construction loan, which bears interest at 3.50% plus LIBOR (subject to a LIBOR floor of 0.25%) per annum and matures in July 2025. In addition to its $34.8 million credit for contribution of the leasehold interest at 3025 JFK Venture, the Company has funded $20.5 million of project costs as of December 31, 2021. The remaining project costs will be funded by the joint venture partner and the construction loan. The Company has determined that the 3025 JFK Venture is a variable interest entity ("VIE"). As a result, the Company used the VIE model under the accounting standard for consolidation in order to determine whether to consolidate the 3025 JFK Venture. Based upon each member’s shared power over the activities of 3025 JFK Venture under the operating and related agreements, and the Company’s lack of control over the development and construction phases of the project, 3025 JFK Venture is accounted for under the equity method of accounting. Mid-Atlantic Office JV On December 21, 2020, the Company contributed a portfolio of twelve properties containing an aggregate of 1,128,645 square feet, nine of which are located in the Pennsylvania suburbs segment and three located in the Metropolitan Washington, D.C segment, to the Mid-Atlantic Office JV, for a gross sales price of $192.9 million. After the transaction, the Company owns approximately 25% of the equity interest in the Mid-Atlantic Office JV through a $20.0 million preferred equity holding and approximately 15% of the equity interest through a common equity interest (representing 20% of the total common equity), for a combined approximately 40% equity interest in the venture. On the closing date, Mid-Atlantic Office JV also obtained $147.4 million of third-party debt financing secured by the twelve properties within the venture, with an initial advance of $120.8 million. During the fourth quarter 2021, the Mid-Atlantic Office JV borrowed an additional $2.2 million. The remaining funds available under the loan are $24.4 million. The loan bears interest at LIBOR + 3.15% capped at a total maximum interest rate of 5.6% and matures on January 9, 2024. Commerce Square Venture On July 21, 2020, the Company sold a 30% preferred equity interest in the entities that own One Commerce Square and Two Commerce Square, two office properties containing 1,896,142 square feet in Philadelphia, Pennsylvania. After the transaction, the Company owns approximately 32% of the equity interest in Commerce Square Venture through preferred equity interest holdings and approximately 38% of the equity interest in Commerce Square Venture as the sole common equity holder, for a combined approximately 70% equity interest in the venture. The properties held by the venture remain encumbered by the existing mortgages. PJP Ventures On October 29, 2019, PJP II, PJP VII and PJP VI, three real estate ventures in which the Company owned a 25%-30% interest, each sold its sole operating office property, totaling 204,347 rentable square feet in Charlottesville, Virginia, at an aggregate sales price of $51.0 million. The Company received cash proceeds of $9.1 million after closing costs and related debt payoffs. The Company recorded an $8.0 million gain within the caption "Net gains on real estate venture transactions" within its consolidated statements of operations for the year ended December 31, 2019. Herndon Innovation Center Metro Portfolio Venture, LLC The Herndon Innovation Center Metro Portfolio Venture, LLC (“Herndon Innovation Center”) consists of eight properties containing an aggregate of 1,293,197 square feet, located in the Metropolitan Washington, D.C. segment. The Company and its partner own 15% and 85% interests in the Herndon Innovation Center, respectively. On March 29, 2019, Herndon Innovation Center obtained $134.1 million of third-party debt financing, secured by four properties within the venture, with an initial advance of $113.1 million. The remaining funds available under the loan have not yet been drawn. The Company received $16.7 million for its share of the cash proceeds on April 12, 2019. The loan bears interest at LIBOR + 1.95% capped at a total maximum interest rate of 5.45% - 6.45% over the term of the loan and matures on March 29, 2024. On April 11, 2019, the venture obtained an additional $115.3 million of third-party debt financing secured by the remaining four properties within the venture, with an initial advance of $94.2 million. The remaining funds available under the loan have not yet been drawn. The loan bears interest at LIBOR + 1.80% capped at a total maximum interest rate of 6.3% and matures on April 11, 2024. On April 12, 2019, the Company received $13.8 million for its share of the cash proceeds from the financing. MAP Venture The MAP Venture owns 58 office properties that contain an aggregate of 3,924,783 square feet located in the Pennsylvania Suburbs, New Jersey/Delaware, Metropolitan Washington, D.C. and Richmond, Virginia ("MAP Venture"). The MAP Venture leases the land parcels under the 58 office properties through a ground lease that extends through February 2115. Annual payments by the MAP Venture, as tenant under the ground lease, initially total $11.9 million and increase 2.5% annually through November 2025. Thereafter, annual rental payments increase by 2.5% or CPI at the discretion of the lessor. 1919 Venture 1919 Venture owns a 29-story, 455,000 square foot mixed-use tower consisting of 321 luxury apartments, 24,000 square feet of commercial space and a 215-car structured parking facility. See Note 5, ''Debt and Preferred Equity Investments" for additional information regarding the related-party note receivable with 1919 Venture. JBG Ventures JBG Ventures consists of 51 N 50 Patterson, Holdings, LLC Venture ("51 N Street") and 1250 First Street Office, LLC Venture ("1250 First Street"), with the Company owning a 70.0% equity interest and JBG/DC Manager, LLC ("JBG") owning a 30.0% equity interest in each of the two ventures. 51 N Street owns 0.9 acres of undeveloped land and 1250 First Street, owns 0.5 acres of undeveloped land.

DEBT AND PREFERRED EQUITY INVES

DEBT AND PREFERRED EQUITY INVESTMENTS	12 Months Ended
	Dec. 31, 2021
Investments, Debt and Equity Securities [Abstract]
DEBT AND PREFERRED EQUITY INVESTMENTS	5. DEBT AND PREFERRED EQUITY INVESTMENTS Austin Preferred Equity Investment On December 31, 2020, the Company invested $50.0 million in exchange for a preferred equity interest in a single-purpose entity that owned two stabilized office buildings located in Austin, Texas. The Company accounted for this mandatorily redeemable investment as a note receivable, which was included within "Other assets" on the consolidated balance sheets.The preferred equity interest accrued a 9.0% annual return, compounded and paid monthly. The investment was required to be redeemed no later than December 31, 2023 (subject to a one-year extension option). On September 3, 2021, the $50.0 million investment was redeemed prior to maturity. As a result, the Company recognized an incremental $2.8 million of income on early redemption related to its accelerated minimum return and exit fees paid in cash on the redemption date during the three months ended September 30, 2021, which is included in "Interest and investment income" on the consolidated statements of operations. 1919 Venture Note Receivable During 2018, each of the Company and the other equity partner in 1919 Venture, an unconsolidated real estate venture, provided a $44.4 million mortgage loan to 1919 Venture and, as a result, the Company recorded a $44.4 million related-party note receivable from 1919 Venture. The loan bears interest at a fixed 4.0% per annum interest rate with a scheduled maturity on June 25, 2023. 1919 Venture used the proceeds from the loans to repay its then outstanding $88.8 million construction loan. See Note 4, ''Investment in Unconsolidated Real Estate Ventures” for further information regarding 1919 Venture. As of December 31, 2021, the debt investment was performing in accordance with its terms and remains on accrual status.

LEASES

LEASES	12 Months Ended
	Dec. 31, 2021
Leases [Abstract]
LEASES	6. LEASES Lessor Accounting The Company leases properties to tenants under operating leases with various expiration dates. Future contractual lease payments under operating leases at December 31, 2021 are as follows (in thousands): Year 2022 $ 328,553 2023 327,981 2024 304,240 2025 274,216 2026 249,045 Thereafter 952,898 Lessee Accounting As of December 31, 2021, the Company is the lessee under six long-term ground leases classified as "operating leases" in the consolidated balance sheets. Certain of the Company’s ground leases contain extension options and the Company considered all relevant factors in determining if it was reasonably certain that it would exercise such extension options. The Company concluded that it was not reasonably certain that it would exercise the extension options and, therefore, has not included the extension period in the remaining lease terms. With the exception of certain ground leases that are subject to rent increases periodically based on the CPI index, all lease payments under the ground lease are fixed. The table below summarizes the Company’s operating lease cost (in thousands) recognized through “Property operating expenses” on the consolidated statements of operations (in thousands): Year Ended December 31, Lease Cost 2021 2020 Fixed lease cost $ 2,100 $ 2,100 Variable lease cost 43 45 Total $ 2,143 $ 2,145 Weighted-average remaining lease term (years) 55.2 55.9 Weighted-average discount rate 6.3 % 6.3 % Lease payments by the Company under the terms of all noncancellable ground leases of land are expensed on a straight-line basis regardless of when payments are due. The Company’s ground leases, excluding prepaid ground leases, have remaining lease terms ranging from 8 to 63 years. Lease payments on noncancellable leases at December 31, 2021 are as follows (in thousands): Year Minimum Rent 2022 $ 1,248 2023 1,263 2024 1,305 2025 1,321 2026 1,338 Thereafter 107,793 Total lease payments $ 114,268 Less: Imputed interest 91,306 Present value of operating lease liabilities $ 22,962 The Company obtained ground tenancy rights related to three properties in Philadelphia, Pennsylvania, which provide for contingent rent participation by the lessor in certain capital transactions and net operating cash flows of the properties after certain returns are achieved by the Company. Such amounts, if any, will be reflected as contingent rent when incurred. The ground leases also provide for payment by the Company of certain operating costs relating to the land, primarily real estate taxes. The above schedule of future minimum rental payments does not include any contingent rent amounts or any reimbursed expenses.
LEASES	6. LEASES Lessor Accounting The Company leases properties to tenants under operating leases with various expiration dates. Future contractual lease payments under operating leases at December 31, 2021 are as follows (in thousands): Year 2022 $ 328,553 2023 327,981 2024 304,240 2025 274,216 2026 249,045 Thereafter 952,898 Lessee Accounting As of December 31, 2021, the Company is the lessee under six long-term ground leases classified as "operating leases" in the consolidated balance sheets. Certain of the Company’s ground leases contain extension options and the Company considered all relevant factors in determining if it was reasonably certain that it would exercise such extension options. The Company concluded that it was not reasonably certain that it would exercise the extension options and, therefore, has not included the extension period in the remaining lease terms. With the exception of certain ground leases that are subject to rent increases periodically based on the CPI index, all lease payments under the ground lease are fixed. The table below summarizes the Company’s operating lease cost (in thousands) recognized through “Property operating expenses” on the consolidated statements of operations (in thousands): Year Ended December 31, Lease Cost 2021 2020 Fixed lease cost $ 2,100 $ 2,100 Variable lease cost 43 45 Total $ 2,143 $ 2,145 Weighted-average remaining lease term (years) 55.2 55.9 Weighted-average discount rate 6.3 % 6.3 % Lease payments by the Company under the terms of all noncancellable ground leases of land are expensed on a straight-line basis regardless of when payments are due. The Company’s ground leases, excluding prepaid ground leases, have remaining lease terms ranging from 8 to 63 years. Lease payments on noncancellable leases at December 31, 2021 are as follows (in thousands): Year Minimum Rent 2022 $ 1,248 2023 1,263 2024 1,305 2025 1,321 2026 1,338 Thereafter 107,793 Total lease payments $ 114,268 Less: Imputed interest 91,306 Present value of operating lease liabilities $ 22,962 The Company obtained ground tenancy rights related to three properties in Philadelphia, Pennsylvania, which provide for contingent rent participation by the lessor in certain capital transactions and net operating cash flows of the properties after certain returns are achieved by the Company. Such amounts, if any, will be reflected as contingent rent when incurred. The ground leases also provide for payment by the Company of certain operating costs relating to the land, primarily real estate taxes. The above schedule of future minimum rental payments does not include any contingent rent amounts or any reimbursed expenses.

DEFERRED COSTS

DEFERRED COSTS	12 Months Ended
	Dec. 31, 2021
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
DEFERRED COSTS	7. DEFERRED COSTS As of December 31, 2021 and 2020, the Company’s deferred costs were comprised of the following (in thousands): December 31, 2021 Total Cost Accumulated Amortization Deferred Costs, net Leasing costs $ 143,895 $ (57,445) $ 86,450 Financing costs - Unsecured Credit Facility 6,299 (5,887) 412 Total $ 150,194 $ (63,332) $ 86,862 December 31, 2020 Total Cost Accumulated Amortization Deferred Costs, net Leasing costs $ 139,207 $ (55,656) $ 83,551 Financing costs - Unsecured Credit Facility 6,299 (4,994) 1,305 Total $ 145,506 $ (60,650) $ 84,856

INTANGIBLE ASSETS AND LIABILITI

INTANGIBLE ASSETS AND LIABILITIES	12 Months Ended
	Dec. 31, 2021
Goodwill and Intangible Assets Disclosure [Abstract]
INTANGIBLE ASSETS AND LIABILITIES	8. INTANGIBLE ASSETS AND LIABILITIES As of December 31, 2021 and 2020, the Company’s intangible assets/liabilities were comprised of the following (in thousands): December 31, 2021 Total Cost Accumulated Amortization Intangible Assets, net Intangible assets, net: In-place lease value $ 72,376 $ (44,066) $ 28,310 Tenant relationship value 167 (97) 70 Above market leases acquired 486 (310) 176 Total intangible assets, net $ 73,029 $ (44,473) $ 28,556 Total Cost Accumulated Amortization Intangible Liabilities, net Intangible liabilities, net: Below market leases acquired $ 27,025 $ (14,044) $ 12,981 December 31, 2020 Total Cost Accumulated Amortization Intangible Assets, net Intangible assets, net: In-place lease value $ 91,552 $ (43,400) $ 48,152 Tenant relationship value 2,091 (1,938) 153 Above market leases acquired 530 (265) 265 Total intangible assets, net $ 94,173 $ (45,603) $ 48,570 Total Cost Accumulated Amortization Intangible Liabilities, net Intangible liabilities, net: Below market leases acquired $ 31,263 $ (12,815) $ 18,448 For the years ended December 31, 2021, 2020, and 2019, the Company accelerated the amortization of intangible assets by approximately $3.6 million, $0.3 million, and $4.5 million, respectively, as a result of tenant move-outs prior to the end of the associated lease term. For the years ended December 31, 2021, 2020, and 2019 the Company accelerated the amortization of approximately $0.6 million, $0.1 million, and $2.2 million of intangible liabilities as a result of tenant move-outs. As of December 31, 2021, the Company’s annual amortization for its intangible assets/liabilities, assuming no prospective early lease terminations, was as follows (dollars in thousands): Assets Liabilities 2022 $ 9,642 $ 2,588 2023 6,724 1,540 2024 4,433 1,321 2025 3,255 1,044 2026 1,195 754 Thereafter 3,307 5,734 Total $ 28,556 $ 12,981

DEBT OBLIGATIONS

DEBT OBLIGATIONS	12 Months Ended
	Dec. 31, 2021
Debt Disclosure [Abstract]
DEBT OBLIGATIONS	9. DEBT OBLIGATIONS The following table sets forth information regarding the Company’s consolidated debt obligations outstanding as of December 31, 2021 and 2020 (in thousands): December 31, 2021 December 31, 2020 Effective Maturity UNSECURED DEBT $600 million Unsecured Credit Facility $ 23,000 $ — LIBOR + 1.10% July 2022 (a) Seven 250,000 250,000 2.87% October 2022 $350.0M 3.95% Guaranteed Notes due 2023 350,000 350,000 3.87% February 2023 $350.0M 4.10% Guaranteed Notes due 2024 350,000 350,000 3.78% October 2024 $450.0M 3.95% Guaranteed Notes due 2027 450,000 450,000 4.03% November 2027 $350.0M 4.55% Guaranteed Notes due 2029 350,000 350,000 4.30% October 2029 Indenture IA (Preferred Trust I) 27,062 27,062 LIBOR + 1.25% March 2035 Indenture IB (Preferred Trust I) 25,774 25,774 LIBOR + 1.25% April 2035 Indenture II (Preferred Trust II) 25,774 25,774 LIBOR + 1.25% July 2035 Principal balance outstanding 1,851,610 1,828,610 Plus: original issue premium (discount), net 8,187 10,137 Less: deferred financing costs (6,211) (8,152) Total unsecured indebtedness $ 1,853,586 $ 1,830,595 (a) The Company has the ability to extend the term of the Unsecured Credit Facility until July 2023 through two successive six-month extension options. The Parent Company unconditionally guarantees the unsecured debt obligations of the Operating Partnership (or is a co-borrower with the Operating Partnership) but does not by itself incur unsecured indebtedness. The Parent Company has no material assets other than its investment in the Operating Partnership. On July 17, 2018, the Company amended and restated its revolving credit agreement (as amended and restated, the “Unsecured Credit Facility”). The amendment and restatement, among other things: (i) maintained the total commitment of the revolving line of credit of $600.0 million; (ii) extended the maturity date from May 15, 2019 to July 15, 2022, with two six-month extensions at the Company’s election subject to specified conditions and subject to payment of an extension fee; (iii) reduced the interest rate margins applicable to Eurodollar loans; (iv) provided for an additional interest rate option based on a floating LIBOR rate; and (v) removed the covenant requiring the Company to maintain a minimum net worth. In connection with the amendments, the Company capitalized $2.7 million in financing costs, which will be amortized through the July 15, 2022 maturity date. At the Company's option, loans outstanding under the Unsecured Credit Facility will bear interest at a rate per annum equal to (1) LIBOR plus between 0.775% and 1.45%, based on the Company's credit rating, or (2) a base rate equal to the greatest of (a) the Administrative Agent's prime rate, (b) the Federal Funds rate plus 0.5% or (c) LIBOR for a one month period plus 1.00%, in each case, plus a margin ranging from 0.0% to 0.45% based on the Company's credit rating. The Unsecured Credit Facility also contains a competitive bid option that allows banks that are part of the lender consortium to bid to make loan advances to the Company at a reduced interest rate. In addition, the Company is also obligated to pay (1) in quarterly installments a facility fee on the total commitment at a rate per annum ranging from 0.125% to 0.30% based on the Company's credit rating and (2) an annual fee on the undrawn amount of each letter or credit equal to the LIBOR Margin. Based on the Company's current credit rating, the LIBOR margin is 1.10% and the facility fee is 0.25%. The terms of the Unsecured Credit Facility require that the Company maintain customary financial and other covenants, including: (i) a fixed charge coverage ratio greater than or equal to 1.5 to 1.00; (ii) a leverage ratio less than or equal to 0.60 to 1.00, subject to specified exceptions; (iii) a ratio of unsecured indebtedness to unencumbered asset value less than or equal to 0.60 to 1.00, subject to specified exceptions; (iv) a ratio of secured indebtedness to total asset value less than or equal to 0.40 to 1.00; and (v) a ratio of unencumbered cash flow to interest expense on unsecured debt greater than 1.75 to 1.00. In addition, the Unsecured Credit Facility restricts payments of dividends and distributions on shares in excess of 95% of the Company's funds from operations (FFO) except to the extent necessary to enable the Company to continue to qualify as a REIT for Federal income tax purposes. The Company had $23.0 million of borrowings under the Unsecured Credit Facility as of December 31, 2021. During the twelve months ended December 31, 2021, the weighted-average interest rate on Unsecured Credit Facility borrowings was 1.21% resulting in $0.4 million of interest expense. During the twelve months ended December 31, 2020 weighted-average interest rate on Unsecured Credit Facility borrowings was 1.48% resulting in $0.5 million of interest expense. The Company was in compliance with all financial covenants as of December 31, 2021. Certain of the covenants restrict the Company’s ability to obtain alternative sources of capital. As of December 31, 2021, the aggregate scheduled principal payments on the Company's debt obligations were as follows (in thousands): 2022 $ 273,000 2023 350,000 2024 350,000 2025 — 2026 — Thereafter 878,610 Total principal payments 1,851,610 Net unamortized premiums/(discounts) 8,187 Net deferred financing costs (6,211) Outstanding indebtedness $ 1,853,586

FAIR VALUE OF FINANCIAL INSTRUM

FAIR VALUE OF FINANCIAL INSTRUMENTS	12 Months Ended
	Dec. 31, 2021
Fair Value Disclosures [Abstract]
FAIR VALUE OF FINANCIAL INSTRUMENTS	10. FAIR VALUE OF FINANCIAL INSTRUMENTS The Company determined the fair values disclosed below using available market information and discounted cash flow analyses as of December 31, 2021 and 2020, respectively. The discount rate used in calculating fair value is the sum of the current risk free rate and the risk premium on the date of measurement of the instruments or obligations. Considerable judgment is necessary to interpret market data and to develop the related estimates of fair value. Accordingly, the estimates presented are not necessarily indicative of the amounts that the Company could realize upon disposition. The use of different estimates and valuation methodologies may have a material effect on the fair value amounts shown. The Company believes that the carrying amounts reflected in the consolidated balance sheets at December 31, 2021 and 2020 approximate the fair values for cash and cash equivalents, accounts receivable, other assets and liabilities, accounts payable and accrued expenses because they are short-term in duration. The following are financial instruments for which the Company’s estimates of fair value differ from the carrying amounts (in thousands): December 31, 2021 December 31, 2020 Carrying Amount (a) Fair Value Carrying Amount (a) Fair Value Unsecured notes payable $ 1,502,368 $ 1,588,780 $ 1,502,901 $ 1,607,310 Variable rate debt $ 351,218 $ 344,754 $ 327,694 $ 308,838 Notes receivable (b) $ 44,430 $ 45,230 $ 94,430 $ 97,372 (a) Net of deferred financing costs of $5.8 million and $7.2 million for unsecured notes payable, $0.4 million and $0.9 million for variable rate debt as of December 31, 2021 and December 31, 2020, respectively. (b) For further detail, refer to Note 5, ''Debt and Preferred Equity Investments.” The Company used quoted market prices as of December 31, 2021 and December 31, 2020 to value the unsecured notes payable and, as such, categorized them as Level 2. The inputs utilized to determine the fair value of the Company’s variable rate debt are categorized as Level 3. The fair value of the variable rate debt was determined using a discounted cash flow model that considered borrowing rates available to the Company for loans with similar terms and characteristics. The inputs utilized to determine fair value of the Company's notes receivable are unobservable and, as such, were categorized as Level 3. Fair value was determined using a discounted cash flow model that considered the contractual interest and principal payments discounted at a blended interest rate of the notes receivable. For the Company’s Level 3 financial instruments for which fair value is disclosed, an increase in the discount rate used to determine fair value would result in a decrease to the fair value. Conversely, a decrease in the discount rate would result in an increase to the fair value. Disclosure about the fair value of financial instruments is based upon pertinent information available to management as of December 31, 2021 and December 31, 2020. Although management is not aware of any factors that would significantly affect the fair value amounts, such amounts were not comprehensively revalued for purposes of these financial statements since December 31, 2021. Current estimates of fair value may differ from the amounts presented herein.

DERIVATIVE FINANCIAL INSTRUMENT

DERIVATIVE FINANCIAL INSTRUMENTS	12 Months Ended
	Dec. 31, 2021
Derivative Instruments and Hedging Activities Disclosure [Abstract]
DERIVATIVE FINANCIAL INSTRUMENTS	11. DERIVATIVE FINANCIAL INSTRUMENTS Use of Derivative Financial Instruments The Company’s use of derivative instruments is limited to the utilization of interest rate agreements or other instruments to manage interest rate risk exposures and not for speculative purposes. The principal objective of such arrangements is to minimize the risks and/or costs associated with the Company’s operating and financial structure, as well as to hedge specific transactions. The counterparties to these arrangements are major financial institutions with which the Company and its affiliates may also have other financial relationships. The Company is potentially exposed to credit loss in the event of non-performance by these counterparties. However, because of the high credit ratings of the counterparties, the Company does not anticipate that any of the counterparties will fail to meet these obligations as they come due. The Company does not hedge credit or property value market risks through derivative financial instruments. The Company formally assesses, both at the inception of a hedge and on an on-going basis, whether each derivative is highly-effective in offsetting changes in cash flows of the hedged item. If management determines that a derivative is not highly-effective as a hedge or if a derivative ceases to be a highly-effective hedge, the Company will discontinue hedge accounting prospectively for either the entire hedge or the portion of the hedge that is determined to be ineffective. The related ineffectiveness would be charged to the consolidated statement of operations. The valuation of these instruments is determined using widely accepted valuation techniques including discounted cash flow analysis on the expected cash flows of each derivative. This analysis reflects the contractual terms of the derivatives, including the period to maturity, and uses observable market-based inputs, including interest rate curves and implied volatilities. The fair values of interest rate swaps are determined using the market standard methodology of netting the discounted future fixed cash receipts (or payments) and the discounted expected variable cash payments (or receipts). The variable cash payments (or receipts) are based on an expectation of future interest rates (forward curves) derived from observable market interest rate curves. To comply with the provisions of the accounting standard for fair value measurements and disclosures, the Company incorporates credit valuation adjustments to appropriately reflect both its own nonperformance risk and the respective counterparty’s nonperformance risk in the fair value measurements. In adjusting the fair value of its derivative contracts for the effect of nonperformance risk, the Company has considered the impact of netting and any applicable credit enhancements, such as collateral postings, thresholds, mutual puts, and guarantees. The following table summarizes the terms and fair values of the Company’s derivative financial instruments as of December 31, 2021 and December 31, 2020. The notional amounts provide an indication of the extent of the Company’s involvement in these instruments at that time but do not represent exposure to credit, interest rate or market risks (amounts presented in thousands). Hedge Product Hedge Type Designation Notional Amount Strike Trade Date Maturity Date Fair value 12/31/2021 12/31/2020 12/31/2021 12/31/2020 Liabilities Swap Interest Rate Cash Flow (a) $ 250,000 $ 250,000 2.868 % October 8, 2015 October 8, 2022 $ (2,461) $ (6,627) Swap Interest Rate Cash Flow (b) — 25,774 3.300 % December 22, 2011 January 30, 2021 — (120) $ 250,000 $ 275,774 (a) Hedging unsecured variable rate debt. (b) On January 30, 2021, the interest rate hedge contract for this swap expired. The Company measures its derivative instruments at fair value and records them in “Other assets” and (“Other liabilities”) on the Company’s consolidated balance sheets. Although the Company has determined that the majority of the inputs used to value its derivatives fall within Level 2 of the fair value hierarchy, the credit valuation adjustments associated with its derivatives utilize Level 3 inputs, such as estimates of current credit spreads to evaluate the likelihood of default by itself and its counterparties. The Company has assessed the significance of the impact of the credit valuation adjustments on the overall valuation of its derivative positions and has determined that the credit valuation adjustments are not significant to the overall valuation of its derivatives. As a result, the Company has determined that the inputs utilized to determine the fair value of derivative instruments are classified in Level 2 of the fair value hierarchy. Concentration of Credit Risk Concentrations of credit risk arise for the Company when multiple tenants of the Company are engaged in similar business activities, or are located in the same geographic region, or have similar economic features that impact in a similar manner their ability to meet contractual obligations, including those to the Company. The Company regularly monitors its tenant base to assess potential concentrations of credit risk. Management believes the current credit risk portfolio is reasonably well diversified and does not contain an unusual concentration of credit risk. No tenant accounted for 10% or more of the Company’s rents during 2021, 2020 and 2019.

LIMITED PARTNERS' NONCONTROLLIN

LIMITED PARTNERS' NONCONTROLLING INTERESTS IN THE PARENT COMPANY	12 Months Ended
	Dec. 31, 2021
Noncontrolling Interest [Abstract]
LIMITED PARTNERS' NONCONTROLLING INTERESTS IN THE PARENT COMPANY	12. LIMITED PARTNERS' NONCONTROLLING INTERESTS IN THE PARENT COMPANY Noncontrolling interests in the Parent Company’s financial statements relate to redeemable common limited partnership interests in the Operating Partnership held by parties other than the Parent Company and properties which are consolidated but not wholly owned by the Operating Partnership. Operating Partnership The aggregate book value of the noncontrolling interests associated with the redeemable common limited partnership interests in the accompanying consolidated balance sheet of the Parent Company was $8.2 million and $10.5 million as of December 31, 2021 and December 31, 2020, respectively. Under the applicable accounting guidance, the redemption value of limited partnership units are carried at fair value. The Parent Company believes that the aggregate settlement value of these interests (based on the number of units outstanding and the average closing price of the common shares during the last five business days of the quarter) was approximately $11.1 million and $11.7 million as of December 31, 2021 and December 31, 2020, respectively.

BENEFICIARIES' EQUITY OF THE PA

BENEFICIARIES' EQUITY OF THE PARENT COMPANY	12 Months Ended
	Dec. 31, 2021
Equity [Abstract]
BENEFICIARIES' EQUITY OF THE PARENT COMPANY	13. BENEFICIARIES' EQUITY OF THE PARENT COMPANY Earnings per Share (EPS) The following table details the number of shares and net income used to calculate basic and diluted earnings per share (in thousands, except share and per share amounts; results may not add due to rounding): Year Ended December 31, 2021 2020 2019 Basic Diluted Basic Diluted Basic Diluted Numerator Net income $ 12,366 $ 12,366 $ 307,326 $ 307,326 $ 34,529 $ 34,529 Net income attributable to noncontrolling interests (77) (77) (1,799) (1,799) (262) (262) Nonforfeitable dividends allocated to unvested restricted shareholders (421) (421) (410) (410) (396) (396) Net income attributable to common shareholders $ 11,868 $ 11,868 $ 305,117 $ 305,117 $ 33,871 $ 33,871 Denominator Weighted-average shares outstanding 170,878,185 170,878,185 171,926,079 171,926,079 176,132,941 176,132,941 Contingent securities/Share based compensation — 1,395,055 — 390,997 — 553,872 Weighted-average shares outstanding 170,878,185 172,273,240 171,926,079 172,317,076 176,132,941 176,686,813 Earnings per Common Share: Net income attributable to common shareholders $ 0.07 $ 0.07 $ 1.77 $ 1.77 $ 0.19 $ 0.19 The contingent securities/share based compensation impact is calculated using the treasury stock method and relates to employee awards settled in shares of the Parent Company. The effect of these securities is anti-dilutive for periods that the Parent Company incurs a net loss from continuing operations available to common shareholders and therefore is excluded from the dilutive earnings per share calculation in such periods. Redeemable common limited partnership units totaling 823,983 at December 31, 2021, 981,634 at December 31, 2020 and 981,634 at December 31, 2019, respectively, were excluded from the diluted earnings per share computations because they are not dilutive. Unvested restricted shares are considered participating securities which require the use of the two-class method for the computation of basic and diluted earnings per share. For the years ended December 31, 2021, 2020 and 2019, earnings representing nonforfeitable dividends as noted in the table above were allocated to the unvested restricted shares issued to the Company’s executives and other employees under the Company's shareholder-approved long-term incentive plan. Common and Preferred Shares On December 7, 2021, the Parent Company declared a distribution of $0.19 per common share, totaling $32.8 million, which was paid on January 19, 2022 to shareholders of record as of January 5, 2022. During the year ended December 31, 2021, the Company issued 226,695 common shares in a private placement to an unaffiliated third party in exchange for the third party's 1% residual ownership interest in One and Two Commerce Square, an unconsolidated joint venture. Of the 20,000,000 preferred shares authorized, none were outstanding as of December 31, 2021 or December 31, 2020. Common Share Repurchases The Parent Company maintains a common share repurchase program under which the Board of Trustees has authorized the Parent Company to repurchase common shares. On January 3, 2019, the Board of Trustees authorized the repurchase of up to $150.0 million common shares from and after January 3, 2019. During the year ended December 31, 2021, the Company did not repurchase any common shares. During the year ended December 31, 2020, the Company repurchased and retired 6,248,483 common shares at an average price of $9.60 per share, totaling $60.0 million. During the year ended December 31, 2019, the Company repurchased and retired 1,337,169 common shares at an average price of $12.92 per share, totaling $17.3 million. Former Continuous Offering Program On January 10, 2017, the Parent Company entered into a continuous offering program (the “Offering Program”), that permitted the Parent Company to sell up to an aggregate of 16,000,000 common shares in at-the-market offerings. There was no activity under the Offering Program during 2020 and 2019. At December 31, 2021, no common shares remained available for issuance under the Offering Program, which terminated on January 10, 2020.

PARTNERS' EQUITY OF THE PARENT

PARTNERS' EQUITY OF THE PARENT COMPANY	12 Months Ended
	Dec. 31, 2021
Equity [Abstract]
PARTNERS' EQUITY OF THE PARENT COMPANY	14. PARTNERS' EQUITY OF THE PARENT COMPANY Earnings per Common Partnership Unit The following table details the number of units and net income used to calculate basic and diluted earnings per common partnership unit (in thousands, except unit and per unit amounts; results may not add due to rounding): Year Ended December 31, 2021 2020 2019 Basic Diluted Basic Diluted Basic Diluted Numerator Net income $ 12,366 $ 12,366 $ 307,326 $ 307,326 $ 34,529 $ 34,529 Net (income) loss attributable to noncontrolling interests 3 3 (20) (20) (69) (69) Nonforfeitable dividends allocated to unvested restricted unitholders (421) (421) (410) (410) (396) (396) Net income attributable to common unitholders $ 11,948 $ 11,948 $ 306,896 $ 306,896 $ 34,064 $ 34,064 Denominator Weighted-average units outstanding 171,770,843 171,770,843 172,907,713 172,907,713 177,114,932 177,114,932 Contingent securities/Share based compensation — 1,395,055 — 390,997 — 553,872 Total weighted-average units outstanding 171,770,843 173,165,898 172,907,713 173,298,710 177,114,932 177,668,804 Earnings per Common Partnership Unit: Net income attributable to common unitholders $ 0.07 $ 0.07 $ 1.77 $ 1.77 $ 0.19 $ 0.19 Unvested restricted units are considered participating securities which require the use of the two-class method for the computation of basic and diluted earnings per unit. For the years ended December 31, 2021, 2020 and 2019, earnings representing nonforfeitable dividends were allocated to the unvested restricted units issued to the Parent Company’s executives and other employees under the Parent Company’s shareholder-approved long-term incentive plan. Common Partnership Units and Preferred Mirror Units The Operating Partnership issues partnership units to the Parent Company in exchange for the contribution of the net proceeds of any equity security issuance by the Parent Company. The number and terms of such partnership units correspond to the number and terms of the related equity securities issued by the Parent Company. In addition, the Operating Partnership may also issue separate classes of partnership units. Historically, the Operating Partnership has had the following types of partnership units outstanding: (i) Preferred Partnership Units which have been issued to parties other than the Parent Company; (ii) Preferred Mirror Partnership Units which have been issued to the Parent Company; and (iii) Common Partnership Units which include both interests held by the Parent Company and those held by other limited partners. Preferred Mirror Partnership Units In exchange for the proceeds received in corresponding offerings by the Parent Company of preferred shares of beneficial interest, the Operating Partnership has issued to the Parent Company a corresponding amount of Preferred Mirror Partnership Units with terms consistent with that of the preferred securities issued by the Parent Company. No preferred units were outstanding as of December 31, 2021 or December 31, 2020. Common Partnership Units (Redeemable and General) The Operating Partnership has two classes of Common Partnership Units outstanding as of December 31, 2021: (i) Class A Limited Partnership Interest which are held by both the Parent Company and outside third parties and (ii) General Partnership Interests which are held solely by the Parent Company (collectively, the Class A Limited Partnership Interest, and General Partnership Interests are referred to as “Common Partnership Units”). The holders of the Common Partnership Units are entitled to share in cash distributions from, and in profits and losses of, the Operating Partnership, in proportion to their respective percentage interests, subject to preferential distributions on the preferred mirror units and the preferred units. The Common Partnership Units held by the Parent Company (comprised of both General Partnership Units and Class A Limited Partnership Units) are presented as partner’s equity in the consolidated financial statements. Class A Limited Partnership Interest held by parties other than the Parent Company are redeemable at the option of the holder for a like number of common shares of the Parent Company, or cash, or a combination thereof, at the election of the Parent Company. Because the form of settlement of these redemption rights are not within the control of the Operating Partnership, these Common Partnership Units have been excluded from partner’s equity and are presented as redeemable limited partnership units measured at the potential cash redemption value as of the end of the periods presented based on the closing market price of the Parent Company’s common shares at December 31, 2021, 2020 and 2019, which was $13.42, $11.91 and $15.75, respectively. Class A Units of 823,983 as of December 31, 2021, 981,634 as of December 31, 2020, and 981,634 as of December 31, 2019, respectively, were outstanding and owned by outside limited partners of the Operating Partnership. On December 7, 2021, the Operating Partnership declared a distribution of $0.19 per common partnership unit, totaling $32.8 million, which was paid on January 19, 2022 to unitholders of record as of January 5, 2022. During the year ended December 31, 2021, the Operating Partnership issued 226,695 common partnership units to the Parent Company in exchange for a 1% residual ownership interest in One and Two Commerce Square, an unconsolidated joint venture, which was acquired from an unaffiliated third party in exchange for an equal number of common shares of the Parent Company. Common Unit Repurchases In connection with the Parent Company’s common share repurchase program, one common unit of the Operating Partnership is retired for each common share repurchased. During the year ended December 31, 2021, the Company did not repurchase any units. During the year ended December 31, 2020 the Company repurchased and retired 6,248,483 common units at an average price of $9.60 per unit, totaling $60.0 million. During the year ended December 31, 2019, the Company Repurchased 1,337,169 common units at an average price of $12.92 per unit, totaling $17.3 million. The common units repurchased were retired and, as a result, were accounted for in accordance with Maryland law, which does not contemplate treasury stock. The repurchases were recorded as a reduction of common units (at $0.01 par value per unit) and a decrease to General Partnership Capital. Former Continuous Offering Program On January 10, 2017, the Parent Company entered into a continuous offering program (the “Offering Program”), which permitted it to sell up to an aggregate of 16,000,000 common units in at-the-market offerings. In connection with the commencement of the Offering Program, $0.2 million of upfront costs were recorded to General Partner Capital. There was no activity under the Offering Program during 2020 and 2019. As of December 31, 2021, no common shares remained available for issuance under the Offering Program, which terminated on January 10, 2020.

SHARE BASED COMPENSATION, 401(K

SHARE BASED COMPENSATION, 401(K) PLAN AND DEFERRED COMPENSATION	12 Months Ended
	Dec. 31, 2021
Share-based Payment Arrangement [Abstract]
SHARE BASED COMPENSATION, 401(K) PLAN AND DEFERRED COMPENSATION	15. SHARE BASED COMPENSATION, 401(K) PLAN AND DEFERRED COMPENSATION 401(k) Plan The Company sponsors a 401(k) defined contribution plan for its employees. Each employee may contribute up to 100% of annual compensation, subject to specific limitations under the Internal Revenue Code. At its discretion, the Company can make matching contributions equal to a percentage of the employee’s elective contribution and profit sharing contributions. The Company funds its 401(k) contributions annually and plan participants must be employed as of December 31 in order to receive employer contributions, except for employees eligible for qualifying retirement, as defined under the Internal Revenue Code. The Company contributions were $0.4 million, $0.5 million, and $0.4 million in 2021, 2020, and 2019, respectively. Restricted Share Rights Awards As of December 31, 2021, 474,978 restricted share rights ("Restricted Share Rights") were outstanding under the Company's long term equity incentive plan. These Restricted Share Rights vest over one The following table summarizes the Company’s Restricted Share Rights activity during the year-ended December 31, 2021: Shares Weighted Average Grant Date Fair Value Non-vested at January 1, 2021 488,735 $ 15.19 Granted 343,179 $ 12.72 Vested (339,579) $ 15.12 Forfeited (17,357) $ 13.55 Non-vested at December 31, 2021 474,978 $ 13.51 On March 4, 2021, the Compensation Committee of the Parent Company’s Board of Trustees awarded to officers of the Company an aggregate of 252,278 Restricted Share Rights, which vest over three years from the grant date. Each Restricted Share Right entitles the holder to one common share upon settlement. The Parent Company pays dividend equivalents on the Restricted Share Rights prior to the settlement date. Vesting and/or settlement would accelerate if the recipient of the award were to die, become disabled or, in the case of certain of such Restricted Share Rights, retire in a qualifying retirement prior to the vesting or settlement date. Qualifying retirement generally means the recipient’s voluntary termination of employment after reaching at least age 57 and accumulating at least 15 years of service with the Company. In addition, vesting would also accelerate if the Parent Company were to undergo a change of control and, on or before the first anniversary of the change of control, the recipient’s employment were to cease due to a termination without cause or resignation with good reason. The Restricted Share Rights granted in 2021, 2020, and 2019 to certain senior executives include an “outperformance feature” whereby additional shares may be earned, up to 200% of the shares subject to the basic award, based on the Company’s achievement of earnings-based targets and development, or investment, based targets during a three-year performance period with an additional two years to fully vest. In addition to the basic award, up to an aggregate of 388,840, 316,236, and 228,858 shares may be awarded under the outperformance feature for the 2021, 2020, and 2019 awards, respectively, to those senior officers whose Restricted Share Rights awards include the "outperformance feature." As of December 31, 2021, the Company has not recognized any compensation expense related to the outperformance feature for the 2019-2021 awards. The Company will continue to evaluate progression towards achievement of the performance metrics on a quarterly basis and recognize compensation expense for the outperformance feature of these awards should it be determined that achievement of these metrics is probable. In addition, on February 23, 2021, the Compensation Committee awarded non-officer employees an aggregate of 49,267 Restricted Share Rights that generally vest in three equal annual installments. Vesting of these awards is subject to acceleration upon death, disability or termination without cause within one year following a change of control. On May 18, 2021, the Compensation Committee awarded the Trustees an aggregate of 41,634 fully vested common shares. In accordance with the accounting standard for share-based compensation, the Company amortizes share-based compensation costs through the qualifying retirement dates for those executives and Trustees who meet the conditions for qualifying retirement during the scheduled vesting period and whose award agreements provide for vesting upon a qualifying retirement. Restricted Performance Share Units Plan The Compensation Committee of the Parent Company’s Board of Trustees has granted performance share-based awards (referred to as Restricted Performance Share Units, or RPSUs) to officers of the Parent Company. The RPSUs are settled in common shares, with the number of common shares issuable in settlement determined based on the Company’s total shareholder return over specified measurement periods compared to total shareholder returns of comparative groups over the measurement periods. The table below presents certain information as to unvested RPSU awards. RPSU Grant Date 2/21/2019 3/5/2020 3/5/2021 Total (Amounts below in shares, unless otherwise noted) Non-vested at January 1, 2021 206,069 319,600 — 525,669 Granted — — 380,957 380,957 Units Cancelled (3,837) (5,545) (6,796) (16,178) Non-vested at December 31, 2021 202,232 314,055 374,161 890,448 Measurement Period Commencement Date 1/1/2019 1/1/2020 1/1/2021 Measurement Period End Date 12/31/2021 12/31/2022 12/31/2023 Granted 213,728 319,600 380,957 Fair Value of Units on Grant Date (in thousands) $ 4,627 $ 5,389 $ 6,389 The Company values each RPSU on its grant date using a Monte Carlo simulation. The fair values of each award are being amortized over the three year performance period. During the performance period, dividend equivalents are credited as additional RPSUs, subject to the same terms and conditions as the original RPSUs. The performance period will be abbreviated and the determination and delivery of earned shares will be accelerated in the event of a change in control or if the recipient of the award were to die, become disabled or retire in a qualifying retirement prior to the end of the otherwise applicable three year performance period; provided that, in the case of qualifying retirement for the March, 2021 and 2020 grants, the number of shares deliverable will be pro-rated based on the portion of the performance period actually worked before retirement. In accordance with the accounting standard for share-based compensation, the Company amortizes stock-based compensation costs for the February 2019 grant through the qualifying retirement date for those executives who meet the conditions for qualifying retirement during the scheduled vesting period. For the year ended December 31, 2021, the Company recognized amortization of the 2021, 2020 and 2019 RPSU awards of $4.3 million, of which $0.5 million was capitalized consistent with the Company’s policies for capitalizing eligible portions of employee compensation. For the year ended December 31, 2020, amortization for the 2020, 2019 and 2018 RPSU awards was $3.0 million, of which $0.4 million was capitalized consistent with the Company’s policies for capitalizing eligible portions of employee compensation. For the year ended December 31, 2019, amortization for the 2019, 2018, and 2017 RPSU awards was $4.2 million, of which $0.6 million was capitalized consistent with the Company’s policies for capitalizing eligible portions of employee compensation. The remaining compensation expense to be recognized with respect to the non-vested RPSUs at December 31, 2021 was approximately $6.3 million and is expected to be recognized over a weighted average remaining vesting period o f 1.5 years. The Company issued 82,513 common shares on February 1, 2021 in settlement of RPSUs that had been awarded on February 28, 2018 (with a three-year measurement period ended December 31, 2020). Holders of these RPSUs also received a cash dividend of $0.19 per share for these common shares on January 20, 2021. Employee Share Purchase Plan The Parent Company’s shareholders approved the 2007 Non-Qualified Employee Share Purchase Plan (the “ESPP”), which is intended to provide eligible employees with a convenient means to purchase common shares of the Parent Company through payroll deductions and voluntary cash purchases at an amount equal to 85% of the average closing price per share for a specified period. Under the plan document, the maximum participant contribution for the 2021 plan year is limited to the lesser of 20% of compensation or $50,000. The ESPP allows the Parent Company to make open market purchases, which reflects all purchases made under the plan to date. In addition, the number of shares separately reserved for issuance under the ESPP is 1.25 million . E mployees made purchases under the ESPP of $0.6 million during the year ended December 31, 2021, $0.4 million during the year ended December 31, 2020 and $0.5 million during the year ended December 31, 2019. The Company recognized $0.1 million of compensation expense related to the ESPP during each of the years ended December 31, 2021, 2020, and 2019. Compensation expense represents the 15% discount on the purchase price. The Board of Trustees of the Parent Company may terminate the ESPP at its sole discretion at any time. Deferred Compensation In January 2005, the Parent Company adopted a Deferred Compensation Plan (the “Plan”) that allows trustees and certain key employees to defer compensation voluntarily. Compensation expense is recorded for the deferred compensation and a related liability is recognized. Participants may elect designated benchmark investment options for the notional investment of their deferred compensation. The deferred compensation obligation is adjusted for deemed income or loss related to the investments selected. At the time the participants defer compensation, the Company records a liability, which is included in the Company’s consolidated balance sheets. The liability is adjusted for changes in the market value of the participant-selected investments at the end of each accounting period, and the impact of adjusting the liability is recorded as an increase or decrease to compensation cost. The Company has purchased mutual funds which can be utilized as a funding source for the Company’s obligations under the Plan. Participants in the Plan have no interest in any assets set aside by the Company to meet its obligations under the Plan. For each of the years ended December 31, 2021, December 31, 2020 and December 31, 2019, the Company recorded a nominal amount of deferred compensation costs, net of investments in the company-owned policies and mutual funds. Participants in the Plan may elect to have all, or a portion of their deferred compensation invested in the Company’s common shares. The Company holds these shares in a rabbi trust, which is subject to the claims of the Company’s creditors in the event of the Company’s bankruptcy or insolvency. The Plan does not permit diversification of a participant’s deferral allocated to the Company common shares and deferrals allocated to Company common shares can only be settled with a fixed number of shares. In accordance with the accounting standard for deferred compensation arrangements where amounts earned are held in a rabbi trust and invested, the deferred compensation obligation associated with the Company’s common shares is classified as a component of shareholder’s equity and the related shares are treated as shares to be issued and are included in total shares outstanding. At both December 31, 2021 and 2020, 1.2 million of such shares were included in total shares outstanding, respectively. Subsequent changes in the fair value of the common shares are not reflected in operations or shareholders’ equity of the Company.

DISTRIBUTIONS

DISTRIBUTIONS	12 Months Ended
	Dec. 31, 2021
Distributions [Abstract]
DISTRIBUTIONS	16. DISTRIBUTIONS The following table provides the tax characteristics of the 2021, 2020 and 2019 distributions paid: Years ended December 31, 2021 2020 2019 (in thousands, except per share amounts) Common Share Distributions: Ordinary income $ 0.64 $ 0.41 $ 0.62 Capital gain 0.01 0.35 — Non-taxable distributions 0.11 — 0.14 Distributions per share $ 0.76 $ 0.76 $ 0.76 Percentage classified as ordinary income 83.90 % 53.90 % 81.00 % Percentage classified as capital gain 1.20 % 46.10 % — % Percentage classified as non-taxable distribution 14.90 % — % 19.00 %

INCOME TAXES AND TAX CREDIT TRA

INCOME TAXES AND TAX CREDIT TRANSACTIONS	12 Months Ended
	Dec. 31, 2021
Income Tax Disclosure [Abstract]
INCOME TAXES AND TAX CREDIT TRANSACTIONS	17. INCOME TAXES AND TAX CREDIT TRANSACTIONS Income Tax Provision/Benefit The Company accounts for income taxes using the asset and liability method. Under this method, deferred tax assets and liabilities are recognized for the estimated future tax consequences attributable to the differences between the financial statement carrying amounts of existing assets and liabilities and their respective income tax bases, and for net operating loss, capital loss and tax credit carryforwards. The deferred tax assets and liabilities are measured using the enacted income tax rates in effect for the year in which those temporary differences are expected to be realized or settled. The effect on the deferred tax assets and liabilities from a change in tax rates is recognized in earnings in the period when the new rate is enacted. However, deferred tax assets are recognized only to the extent that it is more likely than not that they will be realized based on consideration of all available evidence, including the future reversals of existing taxable temporary differences, future projected taxable income and tax planning strategies. Valuation allowances are provided if, based upon the weight of the available evidence, it is more likely than not that some or all of the deferred tax assets will not be realized. As of December 31, 2021 and 2020 there were no deferred tax assets included within “Other assets” in the consolidated balance sheets. The Company had no accruals for tax uncertainties as of December 31, 2021 and December 31, 2020. For the year ended December 31, 2021, there was no deferred income tax expense and nominal current income tax expense. For the year ended December 31, 2020, there was no deferred income tax expense and $0.2 million of current income tax benefit. For the year ended December 31, 2019, there was $0.1 million of deferred income tax expense and $0.1 million of current income tax benefit. These amounts are included in “Income tax (provision) benefit” in the consolidated statements of operations.

ACCUMULATED OTHER COMPREHENSIVE

ACCUMULATED OTHER COMPREHENSIVE INCOME (LOSS)	12 Months Ended
	Dec. 31, 2021
Stockholders' Equity Note [Abstract]
Accumulated Other Comprehensive Income (Loss)	18. ACCUMULATED OTHER COMPREHENSIVE INCOME (LOSS) The following table details the components of accumulated other comprehensive income (loss) of the Parent Company and the Operating Partnership as of and for the three years ended December 31, 2021 (in thousands): Parent Company Cash Flow Hedges Balance at January 1, 2019 $ 5,029 Change in fair market value during year (8,210) Allocation of unrealized (gains)/losses on derivative financial instruments to noncontrolling interests 41 Amortization of interest rate contracts reclassified from comprehensive income to interest expense 770 Balance at December 31, 2019 $ (2,370) Change in fair market value during year (5,972) Allocation of unrealized (gains)/losses on derivative financial instruments to noncontrolling interests 29 Amortization of interest rate contracts reclassified from comprehensive income to interest expense 752 Balance at December 31, 2020 $ (7,561) Change in fair market value during year 4,817 Allocation of unrealized (gains)/losses on derivative financial instruments to noncontrolling interests (28) Amortization of interest rate contracts reclassified from comprehensive income to interest expense 752 Balance at December 31, 2021 $ (2,020) Operating Partnership Cash Flow Hedges Balance at January 1, 2019 $ 4,725 Change in fair market value during year (8,210) Amortization of interest rate contracts reclassified from comprehensive income to interest expense 770 Balance at December 31, 2019 $ (2,715) Change in fair market value during year (5,972) Amortization of interest rate contracts reclassified from comprehensive income to interest expense 752 Balance at December 31, 2020 $ (7,935) Change in fair market value during year 4,817 Amortization of interest rate contracts reclassified from comprehensive income to interest expense 752 Balance at December 31, 2021 $ (2,366) Over time, the unrealized gains and losses held in Accumulated Other Comprehensive Income (“AOCI”) will be reclassified to interest expense when the related hedged items are recognized in earnings. The current balance held in AOCI is expected to be reclassified to interest expense for realized losses on forecasted debt transactions over the related term of the debt obligation, as applicable. The Company expects to reclassify $0.6 million from AOCI into interest expense within the next twelve months.

SEGMENT INFORMATION

SEGMENT INFORMATION	12 Months Ended
	Dec. 31, 2021
Segment Reporting [Abstract]
SEGMENT INFORMATION	19. SEGMENT INFORMATION As of December 31, 2021, the Company owns and manages properties within five segments: (1) Philadelphia Central Business District ("Philadelphia CBD"), (2) Pennsylvania Suburbs, (3) Austin, Texas (4) Metropolitan Washington, D.C. and (5) Other. The Philadelphia CBD segment includes properties located in the City of Philadelphia, Pennsylvania. The Pennsylvania Suburbs segment includes properties in Chester, Delaware, and Montgomery counties in the Philadelphia suburbs. The Austin, Texas segment includes properties in the City of Austin, Texas. The Metropolitan Washington, D.C. segment includes properties in the District of Columbia, Northern Virginia and Southern Maryland. The Other segment includes properties located in Camden County, New Jersey and New Castle County, Delaware. In addition to the five segments, the corporate group is responsible for cash and investment management, development of certain real estate properties during the construction period, and certain other general support functions. Land held for development and construction in progress is transferred to operating properties by region upon completion of the associated construction or project. The following tables provide selected asset information and results of operations of the Company’s reportable segments (in thousands): Real estate investments, at cost: December 31, 2021 December 31, 2020 Philadelphia CBD $ 1,460,510 $ 1,433,927 Pennsylvania Suburbs 866,223 871,530 Austin, Texas 778,145 728,741 Metropolitan Washington, D.C. 280,921 352,794 Other 86,803 87,117 Operating Properties $ 3,472,602 $ 3,474,109 Corporate Right of use asset - operating leases, net $ 20,313 $ 20,977 Construction-in-progress $ 277,237 $ 210,311 Land held for development $ 114,604 $ 117,984 Prepaid leasehold interests in land held for development, net $ 27,762 $ 39,185 . Net operating income: Year Ended December 31, 2021 2020 2019 Total revenue Operating expenses (a) Net operating income Total revenue Operating expenses (a) Net operating income (loss) Total revenue Operating expenses (a) Net operating income (loss) Philadelphia CBD $ 207,858 $ (73,695) $ 134,163 $ 232,028 $ (82,505) $ 149,523 $ 263,769 $ (100,219) $ 163,550 Pennsylvania Suburbs 124,566 (40,011) 84,555 141,613 (46,281) 95,332 141,084 (47,418) 93,666 Austin, Texas 101,680 (39,374) 62,306 102,982 (39,759) 63,223 104,157 (38,285) 65,872 Metropolitan Washington, D.C. 19,865 (15,386) 4,479 40,223 (20,791) 19,432 51,498 (23,455) 28,043 Other 14,015 (9,840) 4,175 13,469 (9,815) 3,654 14,558 (9,328) 5,230 Corporate 18,835 (10,005) 8,830 4,537 (6,305) (1,768) 5,351 (7,141) (1,790) Operating properties $ 486,819 $ (188,311) $ 298,508 $ 534,852 $ (205,456) $ 329,396 $ 580,417 $ (225,846) $ 354,571 (a) Includes property operating expense, real estate taxes and third party management expense. Unconsolidated real estate ventures: Investment in real estate ventures, at equity Equity in income (loss) of real estate venture As of Year ended December 31, December 31, 2021 December 31, 2020 2021 2020 2019 Philadelphia CBD $ 317,959 $ 268,562 $ (15,191) $ (9,090) $ 328 Metropolitan Washington, D.C. 85,867 99,769 (3,755) (3,019) (4,234) Mid-Atlantic Office JV 31,680 32,996 932 96 — MAP Venture (24,396) (11,516) (8,683) (6,571) (6,102) Other — — — — 86 Total $ 411,110 $ 389,811 $ (26,697) $ (18,584) $ (9,922) Net operating income (“NOI”) is a non-GAAP financial measure, which we define as total revenue less property operating expenses, real estate taxes, and third party management expenses. Property operating expenses that are included in determining NOI consist of costs that are necessary and allocable to our operating properties such as utilities, property-level salaries, repairs and maintenance, property insurance and management fees. General and administrative expenses that are not reflected in NOI primarily consist of corporate-level salaries, amortization of share awards and professional fees that are incurred as part of corporate office management. NOI presented by the Company may not be comparable to NOI reported by other companies that define NOI differently. NOI is the primary measure that is used by the Company's management to evaluate the operating performance of the Company's real estate assets by segment. The Company believes NOI provides useful information to investors regarding the financial condition and results of operations because it reflects only those income and expense items that are incurred at the property level. While NOI is a relevant and widely used measure of operating performance of real estate investment trusts, it does not represent cash flow from operations or net income as defined by GAAP and should not be considered as an alternative to those measures in evaluating our liquidity or operating performance. NOI does not reflect interest expenses, real estate impairment losses, depreciation and amortization costs, capital expenditures and leasing costs. The Company believes that net income (loss), as defined by GAAP, is the most appropriate earnings measure. The following is a reconciliation of consolidated net income (loss), as defined by GAAP, to consolidated NOI, (in thousands): Year Ended December 31, 2021 2020 2019 Net income $ 12,366 $ 307,326 $ 34,529 Plus: Interest expense 62,617 73,911 81,512 Interest expense - amortization of deferred financing costs 2,836 2,904 2,768 Depreciation and amortization 178,105 188,283 210,005 General and administrative expenses 30,153 30,288 32,156 Equity in loss of unconsolidated real estate ventures 26,697 18,584 9,922 Less: Interest and investment income 8,295 1,939 2,318 Income tax (provision) benefit (47) 224 (12) Net gain on disposition of real estate 142 289,461 356 Net gain on sale of undepreciated real estate 2,903 201 2,020 Net gain on real estate venture transactions 2,973 75 11,639 Consolidated net operating income $ 298,508 $ 329,396 $ 354,571

COMMITMENTS AND CONTINGENCIES

COMMITMENTS AND CONTINGENCIES	12 Months Ended
	Dec. 31, 2021
Commitments and Contingencies Disclosure [Abstract]
COMMITMENTS AND CONTINGENCIES	20. COMMITMENTS AND CONTINGENCIES Legal Proceedings The Company is involved from time to time in litigation on various matters, including disputes with tenants, disputes with vendors, employee disputes and disputes arising out of agreements to purchase or sell properties or joint ventures or disputes relating to state and local taxes. Given the nature of the Company’s business activities, these lawsuits are considered routine to the conduct of its business. The result of any particular lawsuit cannot be predicted, because of the very nature of litigation, the litigation process and its adversarial nature, and the jury system. The Company will establish reserves for specific legal proceedings when it determines that the likelihood of an unfavorable outcome is probable and when the amount of loss is reasonably estimable. The Company does not expect that the liabilities, if any, that may ultimately result from such legal actions will have a material adverse effect on the consolidated financial position, results of operations or cash flows of the Company. Environmental As an owner of real estate, the Company is subject to various environmental laws of federal, state, and local governments. The Company’s compliance with existing laws has not had a material adverse effect on its financial condition and results of operations, and the Company does not believe it will have a material adverse effect in the future. However, the Company cannot predict the impact of unforeseen environmental contingencies or new or changed laws or regulations on its current Properties or on properties that the Company may acquire. Fair Value of Contingent Consideration On April 2, 2015, the Company purchased 618 Market Street in Philadelphia, Pennsylvania. The allocated purchase price included contingent consideration of $2.0 million payable to the seller upon commencement of development. The liability was recorded at a fair value of $1.6 million and has fully accreted through interest expense to $2.0 million as of December 31, 2021. The fair value of this contingent consideration was determined using a probability weighted discounted cash flow model based on the period until development was originally expected to commence. The significant inputs to the discounted cash flow model were the discount rate and weighted probability scenarios. As the inputs were unobservable, the Company determined the inputs used to value this liability fall within Level 3 for fair value reporting. Debt Guarantees As of December 31, 2021, the Company's unconsolidated real estate ventures had aggregate indebtedness of $961.5 million. These loans are generally mortgage or construction loans, most of which are nonrecourse to the Company, except for customary recourse carve-outs. In addition, during construction undertaken by the unconsolidated real estate ventures, including the 3025 JFK Venture, the Company has provided, and expects to continue to provide, cost overrun and completion guarantees, as well as customary environmental indemnities and guarantees of customary exceptions to nonrecourse provisions in loan agreements. In the agreement with its partner in the 3025 JFK Venture, the Company agreed to provide cost overrun and completion guaranties for the project under development. With respect to the construction loan obtained by 3025 JFK Venture on July 23, 2021, the Company has also provided a carry guarantee and limited payment guarantee up to 25% of the principal balance of the $186.7 million construction loan. Impact of Natural Disasters and Casualty The Company carries liability insurance to mitigate its exposure to certain losses, including those relating to property damage. The Company records the estimated amount of expected insurance proceeds for property damage and other losses incurred as an asset (typically a receivable from the insurer) and income up to the amount of the losses incurred when receipt of insurance proceeds is deemed probable. Any amount of insurance recovery in excess of the amount of the losses is considered a gain contingency and is not recorded until the proceeds are received. In February 2021, one of the Company's properties in Austin, Texas sustained damage from the winter storms and resulting power grid failures. As a result of the damage, during the year ended December 31, 2021, the Company recorded a fixed asset write-off totaling $1.2 million. During the year ended December 31, 2021, the Company has recorded an estimated $7.2 million of restoration costs, of which $1.9 million is included in Accounts payable and accrued expenses on the consolidated balance sheets as of December 31, 2021. The Company has also sustained business interruption loss of $3.9 million related to unpaid rent, which is also fully covered under the insurance policy. During the year ended December 31, 2021, the Company has received $15.3 million of insurance proceeds, resulting in full recovery of the costs incurred to date. The $3.0 million of insurance proceeds received in excess of the fixed asset write-off, total business interruption, and total estimated restoration cost during the year ended December 31, 2021 is included in Other income on the consolidated statement of operations. Other Commitments or Contingencies Under the terms of each of the One Uptown joint venture agreements, the joint venture partner is not required to fund project costs until the closing of the applicable construction loans. In the event that the Company does not close on the applicable construction loan for each of the joint ventures by June 30, 2022, the joint venture partner could elect to assign its interest in the project to the Company and have no obligation to fund the project costs. In addition, the Company has provided cost overrun and completion guarantees, as well as customary environmental indemnities, for each of the One Uptown joint ventures. See Note 3, ''Real Estate Investments” for further information regarding the One Uptown joint ventures. In connection with the Schuylkill Yards Project, the Company entered into a neighborhood engagement program and, as of December 31, 2021, had $7.0 million of future fixed contractual obligations. The Company also committed to fund additional contributions under the program. As of December 31, 2021, the Company estimates that these additional contributions, which are not fixed under the terms of agreement, will be $2.4 million. In connection with the formation of the Commerce Square Venture, the Company has committed to investing an additional $20.0 million of preferred equity in the properties on a pari passu basis with its joint venture partner of which $2.1 million has been contributed by the Company as of December 31, 2021. As part of the Company’s September 2004 acquisition of a portfolio of properties from The Rubenstein Company (which the Company refers to as the “TRC acquisition”), the Company acquired its interest in Two Logan Square, a 708,844 square foot office building in Philadelphia, Pennsylvania primarily through its ownership of a second and third mortgage secured by this property. This property is consolidated, as the borrower is a variable interest entity and the Company, through its ownership of the second and third mortgages, is the primary beneficiary. On October 21, 2020, the Company also acquired the $79.8 million first mortgage on the property from the third-party mortgage lender pursuant to an agreement with certain of the former owners. Under the agreement, the Company has agreed to not take title to Two Logan until the earlier of June 2026 or the occurrence of certain events related to the ownership interests of certain former owners. If the Company were to sell the restricted property before the expiration of the restricted period in a non-exempt transaction, the Company may be required to make significant payments to certain of the former owners of Two Logan Square on account of tax liabilities attributed to them. Additionally, the Company will be required to pay these certain former owners an amount estimated at approximately $0.6 million to redeem their residual interest in the fee owner of this property. The $0.6 million payment is included within "Other liabilities" on the consolidated balance sheets. The Company invests in its properties and regularly incurs capital expenditures in the ordinary course of business to maintain the properties. The Company believes that such expenditures enhance its competitiveness. The Company also enters into construction, utility and service contracts in the ordinary course of business which may extend beyond one year. These contracts typically provide for cancellation with insignificant or no cancellation penalties.

Schedule II - Valuation and Qua

Schedule II - Valuation and Qualifying Accounts	12 Months Ended
	Dec. 31, 2021
SEC Schedule, 12-09, Valuation and Qualifying Accounts [Abstract]
Schedule II Valuation and Qualifying Accounts	Schedule II Valuation and Qualifying Accounts (in thousands) Description Balance at Beginning of Year Additions Deductions (1) Balance at End of Year Allowance for doubtful accounts: December 31, 2021 $ 5,086 $ — $ 953 $ 4,133 December 31, 2020 $ 7,975 $ — $ 2,889 $ 5,086 December 31, 2019 $ 12,919 $ — $ 4,944 $ 7,975

Schedule III - Real Estate and

Schedule III - Real Estate and Accumulated Depreciation	12 Months Ended
	Dec. 31, 2021
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation Disclosure [Abstract]
Real Estate and Accumulated Depreciation	BRANDYWINE REALTY TRUST AND BRANDYWINE OPERATING PARTNERSHIP, L.P. Schedule III Real Estate and Accumulated Depreciation — December 31, 2021 (in thousands) Initial Cost Gross Amount Which Carried Property Name City State Land Building & Improvements Net Improvements (Retirements) Since Acquisition Land Building & Improvements Total (a) Accumulated Depreciation at December 31, 2021 (b) Year of Construction Year Acquired Depreciable Life PENNSYLVANIA SUBURBS Six Tower Bridge (181 Washington Street) Conshohocken PA $ 6,927 $ 14,722 $ 1,747 $ 6,237 $ 17,159 $ 23,396 $ 4,436 1999 2013 (c) 426 West Lancaster Avenue Devon PA 1,689 6,756 9,400 1,686 16,159 17,845 1,614 1990 1998 (c) 640 Freedom Business Center (d) King Of Prussia PA 1,015 20,098 4,252 360 25,005 25,365 15,445 1991 1998 (c) 620 Freedom Business Center (d) King Of Prussia PA 666 13,118 1,498 234 15,048 15,282 9,596 1986 1998 (c) 1000 First Avenue King Of Prussia PA — 13,708 2,806 — 16,514 16,514 11,778 1980 1998 (c) 1060 First Avenue King Of Prussia PA — 13,665 4,014 — 17,679 17,679 12,249 1987 1998 (c) 630 Freedom Business Center Drive (d) King Of Prussia PA 666 13,251 2,937 237 16,617 16,854 10,322 1989 1998 (c) 1020 First Avenue King Of Prussia PA — 10,744 4,306 — 15,050 15,050 10,380 1984 1998 (c) 1040 First Avenue King Of Prussia PA — 14,142 4,915 — 19,057 19,057 13,367 1985 1998 (c) 610 Freedom Business Center Drive (d) King Of Prussia PA 485 9,602 2,415 172 12,330 12,502 8,007 1985 1998 (c) 650 Park Avenue King Of Prussia PA 1,916 4,378 (4,378) 1,916 — 1,916 — 1968 1998 (c) 600 Park Avenue King Of Prussia PA 1,012 4,048 385 1,012 4,433 5,445 2,888 1964 1998 (c) 933 First Avenue King Of Prussia PA 3,127 20,794 (1,125) 3,127 19,669 22,796 3,954 2017 N/A (c) 500 North Gulph Road King Of Prussia PA 1,303 5,201 21,471 1,303 26,672 27,975 3,526 1979 1996 (c) 401 Plymouth Road Plymouth Meeting PA 6,199 16,131 15,622 6,199 31,753 37,952 16,559 2001 2000 (c) Metroplex (4000 Chemical Road) Plymouth Meeting PA 4,373 24,546 5,498 4,373 30,044 34,417 8,667 2007 2001 (c) 610 West Germantown Pike Plymouth Meeting PA 3,651 14,514 4,493 3,651 19,007 22,658 9,635 1987 2002 (c) 600 West Germantown Pike Plymouth Meeting PA 3,652 15,288 2,692 3,652 17,980 21,632 8,989 1986 2002 (c) 630 West Germantown Pike Plymouth Meeting PA 3,558 14,743 2,221 3,558 16,964 20,522 8,623 1988 2002 (c) 620 West Germantown Pike Plymouth Meeting PA 3,572 14,435 2,541 3,572 16,976 20,548 7,992 1990 2002 (c) 660 West Germantown Pike Plymouth Meeting PA 3,694 5,487 19,473 5,405 23,249 28,654 7,549 1987 2012 (c) 351 Plymouth Road Plymouth Meeting PA 1,043 555 — 1,043 555 1,598 232 N/A 2000 (c) 150 Radnor Chester Road Radnor PA 11,925 36,986 21,940 11,897 58,954 70,851 23,715 1983 2004 (c) One Radnor Corporate Center Radnor PA 7,323 28,613 18,811 7,323 47,424 54,747 33,343 1998 2004 (c) 201 King of Prussia Road Radnor PA 8,956 29,811 4,816 8,949 34,634 43,583 22,224 2001 2004 (c) 555 Lancaster Avenue Radnor PA 8,014 16,508 10,137 8,609 26,050 34,659 11,546 1973 2004 (c) Four Radnor Corporate Center Radnor PA 5,406 21,390 11,094 5,705 32,185 37,890 17,219 1995 2004 (c) Five Radnor Corporate Center Radnor PA 6,506 25,525 8,682 6,578 34,135 40,713 15,124 1998 2004 (c) Three Radnor Corporate Center Radnor PA 4,773 17,961 2,016 4,791 19,959 24,750 11,401 1998 2004 (c) Two Radnor Corporate Center Radnor PA 3,937 15,484 2,685 3,942 18,164 22,106 11,120 1998 2004 (c) 130 Radnor Chester Road Radnor PA 2,573 8,338 (134) 2,567 8,210 10,777 3,997 1983 2004 (c) 170 Radnor Chester Road Radnor PA 2,514 8,147 1,667 2,509 9,819 12,328 5,138 1983 2004 (c) 200 Radnor Chester Road Radnor PA 3,366 — 3,621 3,366 3,621 6,987 995 2014 2005 (c) 101 West Elm Street W. Conshohocken PA 6,251 25,209 3,057 6,251 28,266 34,517 11,729 1999 2005 (c) 1 West Elm Street W. Conshohocken PA 3,557 14,249 7,712 3,557 21,961 25,518 6,723 1999 2005 (c) Four Tower Bridge (200 Barr Harbor Drive) W. Conshohocken PA 6,000 14,734 402 6,000 15,136 21,136 1,650 1998 2018 (c) Initial Cost Gross Amount Which Carried December 31, 2021 Property Name City State Land Building & Improvements Net Improvements (Retirements) Since Acquisition Land Building & Improvements Total (a) Accumulated Depreciation at December 31, 2021 (b) Year of Construction Year Acquired Depreciable Life PHILADELPHIA CBD Cira Centre (2929 Arch Street) Philadelphia PA — 208,570 (22,427) 12,586 173,557 186,143 67,765 2005 N/A (c) Three Logan Square (1717 Arch Street) Philadelphia PA — 98,188 84,992 25,195 157,985 183,180 54,136 1990 2010 (c) One Logan Square (130 North 18th Street) Philadelphia PA 14,496 107,736 21,633 14,473 129,392 143,865 65,373 1998 2004 (c) Two Logan Square (100 North 18th Street) Philadelphia PA 16,066 100,255 26,795 16,066 127,050 143,116 56,054 1988 2004 (c) Cira Centre South Garage (129 South 30th Street) (d) Philadelphia PA — 76,008 26,885 6,727 96,166 102,893 25,080 2010 N/A (c) 1900 Market Street Philadelphia PA 7,768 17,263 61,783 7,768 79,046 86,814 25,142 1981 2012 (c) 3020 Market Street Philadelphia PA — 21,417 7,751 — 29,168 29,168 12,800 1959 2011 (c) 618-634 Market Street Philadelphia PA 13,365 5,791 5,186 13,365 10,977 24,342 6,821 1966 2015 (c) FMC Tower at Cira Centre South (2929 Walnut Street) Philadelphia PA — 400,294 9,493 — 409,787 409,787 70,803 2016 N/A (c) 2100 Market Street Philadelphia PA 18,827 — 6,300 18,854 6,273 25,127 1,858 N/A 2015 (c) 1505-11 Race Street Philadelphia PA 3,662 6,061 8 3,670 6,061 9,731 177 1922 2020 (c) 3000 Market Street (e) Philadelphia PA 18,924 13,080 16,264 18,924 29,344 48,268 504 1937 2017 (c) The Bulletin Building (3025 Market Street) (e) Philadelphia PA — 24,377 43,599 — 67,976 67,976 7,928 1953 2017 (c) 3001-3003 JFK Boulevard (f) Philadelphia PA — — 111 — 111 111 24 N/A 2018 N/A METROPOLITAN WASHINGTON, D.C. 6600 Rockledge Drive Bethesda MD — 37,421 9,956 — 47,377 47,377 17,816 1981 2006 (c) 1676 International Drive McLean VA 18,437 97,538 25,740 18,785 122,930 141,715 31,083 1999 2006 (c) 8260 Greensboro Drive McLean VA 7,952 33,964 8,114 8,102 41,928 50,030 13,598 1980 2006 (c) 8521 Leesburg Pike Vienna VA 4,316 30,885 6,575 4,397 37,379 41,776 14,332 1984 2006 (c) AUSTIN, TX 401-405 Colorado Street (g) Austin TX — 47,132 — — 47,132 47,132 491 2021 N/A (c) 11501 Burnet Road - Building 1 Austin TX 3,755 22,702 4 3,755 22,706 26,461 6,062 1991 2015 (c) 11501 Burnet Road - Building 2 Austin TX 2,732 16,305 1,473 2,732 17,778 20,510 5,252 1991 2015 (c) 11501 Burnet Road - Building 3 Austin TX 3,688 22,348 (1,510) 3,688 20,838 24,526 5,560 1991 2015 (c) 11501 Burnet Road - Building 4 Austin TX 2,614 15,740 3 2,614 15,743 18,357 4,203 1991 2015 (c) 11501 Burnet Road - Building 5 Austin TX 3,689 22,354 4 3,689 22,358 26,047 5,970 1991 2015 (c) 11501 Burnet Road - Building 6 Austin TX 2,676 15,972 13,964 2,676 29,936 32,612 8,808 1991 2015 (c) 11501 Burnet Road - Building 8 Austin TX 1,400 7,422 1,521 1,400 8,943 10,343 2,452 1991 2015 (c) 11501 Burnet Road - Parking Garage Austin TX — 19,826 3 — 19,829 19,829 6,289 1991 2015 (c) Four Points Centre 3 (11120 Four Points Drive) Austin TX 1,140 — 40,322 1,141 40,321 41,462 5,062 2019 2013 (c) One Barton Skyway (1501 South MoPac Expressway) Austin TX 10,496 47,670 5,421 10,495 53,092 63,587 4,697 1999 2018 (c) Two Barton Skyway (1601 South MoPac Expressway) Austin TX 10,849 53,868 3,454 10,848 57,323 68,171 5,390 2000 2018 (c) Three Barton Skyway (1221 South MoPac Expressway) Austin TX 10,374 47,624 286 10,373 47,911 58,284 3,865 2001 2018 (c) Four Barton Skyway (1301 South MoPac Expressway) Austin TX 13,301 57,041 4,060 13,300 61,102 74,402 5,044 2001 2018 (c) Initial Cost Gross Amount Which Carried December 31, 2021 Property Name City State Land Building & Improvements Net Improvements (Retirements) Since Acquisition Land Building & Improvements Total (a) Accumulated Depreciation at December 31, 2021 (b) Year of Construction Year Acquired Depreciable Life Four Points Centre (11305 Four Points Drive) Austin TX 7,800 43,581 3,981 7,800 47,562 55,362 4,640 2008 2018 (c) River Place - Building 1 (6500 River Place Boulevard) Austin TX 2,004 17,680 547 2,004 18,227 20,231 1,624 2000 2018 (c) River Place - Building 2 (6500 River Place Boulevard) Austin TX 3,137 29,254 675 3,137 29,929 33,066 2,490 2000 2018 (c) River Place - Building 3 (6500 River Place Boulevard) Austin TX 3,064 26,705 294 3,064 26,999 30,063 2,164 2000 2018 (c) River Place - Building 4 (6500 River Place Boulevard Austin TX 2,273 18,617 1,141 2,273 19,758 22,031 2,030 2000 2018 (c) River Place - Building 5 (6500 River Place Boulevard) Austin TX 1,752 14,315 106 1,752 14,421 16,173 1,161 2001 2018 (c) River Place - Building 6 (6500 River Place Boulevard) Austin TX 1,598 12,945 30 1,598 12,975 14,573 1,027 2001 2018 (c) River Place - Building 7 (6500 River Place Boulevard) Austin TX 1,801 16,486 1,103 1,801 17,589 19,390 1,837 2002 2018 (c) Quarry Lake II (4516 Seton Center Parkway) Austin TX 3,970 30,546 1,024 3,867 31,673 35,540 2,681 1998 2018 (c) OTHER 10 Foster Avenue Gibbsboro NJ 244 971 110 244 1,081 1,325 666 1983 1997 (c) 7 Foster Avenue Gibbsboro NJ 231 921 31 231 952 1,183 601 1983 1997 (c) 2 Foster Avenue Gibbsboro NJ 185 730 11 185 741 926 741 1974 1997 (c) 4 Foster Avenue Gibbsboro NJ 183 726 6 183 732 915 732 1974 1997 (c) 1 Foster Avenue Gibbsboro NJ 93 364 8 93 372 465 372 1972 1997 (c) 5 U.S. Avenue Gibbsboro NJ 21 81 2 21 83 104 83 1987 1997 (c) 5 Foster Avenue Gibbsboro NJ 9 32 3 9 35 44 35 1968 1997 (c) Main Street - Plaza 1000 Voorhees NJ 2,732 10,942 284 2,732 11,226 13,958 11,036 1988 1997 (c) Main Street - Piazza Voorhees NJ 696 2,802 3,631 704 6,425 7,129 4,214 1990 1997 (c) Main Street - Promenade Voorhees NJ 532 2,052 285 532 2,337 2,869 1,476 1988 1997 (c) 920 North King Street Wilmington DE 6,141 21,140 8,037 6,141 29,177 35,318 15,938 1989 2004 (c) 300 Delaware Avenue Wilmington DE 6,369 13,739 2,468 6,369 16,207 22,576 9,731 1989 2004 (c) Total: $ 365,011 $ 2,472,362 $ 635,229 $ 410,144 $ 3,062,458 $ 3,472,602 $ 957,450 The following table reconciles the real estate investments from January 1, 2019 to December 31, 2021 (in thousands): 2021 2020 2019 Balance at beginning of year $ 3,474,109 $ 4,006,459 $ 3,951,719 Additions: Acquisitions — 9,722 — Capital expenditures and assets placed into service 134,931 113,221 145,378 Less: Dispositions/impairments/placed into redevelopment (82,247) (619,086) (50,792) Retirements (54,191) (36,207) (39,846) Balance at end of year $ 3,472,602 $ 3,474,109 $ 4,006,459 Per consolidated balance sheet $ 3,472,602 $ 3,474,109 $ 4,006,459 The aggregate cost for federal income tax purposes is $3.1 billion as of December 31, 2021. (b) Reconciliation of Accumulated Depreciation: The following table reconciles the accumulated depreciation on real estate investments from January 1, 2019 to December 31, 2021 (in thousands): 2021 2020 2019 Balance at beginning of year $ 896,561 $ 973,318 $ 885,407 Additions: Depreciation expense 136,171 138,822 144,131 Less: Dispositions/impairments/placed into redevelopment (24,440) (182,526) (16,783) Retirements (50,842) (33,053) (39,437) Balance at end of year $ 957,450 $ 896,561 $ 973,318 Per consolidated balance sheet $ 957,450 $ 896,561 $ 973,318 (c) Depreciation of the buildings and improvements are calculated over lives ranging from the life of the lease to 55 years. (d) Land value represents unamortized prepaid ground lease. (e) Reflects original construction date. Significant improvements were made to 3000 Market Street in 1988 and to The Bulletin Building in 2012.

SUMMARY OF SIGNIFICANT ACCOUN_2

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Policies)	12 Months Ended
	Dec. 31, 2021
Accounting Policies [Abstract]
Principles of Consolidation	Principles of Consolidation The Company consolidates variable interest entities (“VIEs”) in which it is considered to be the primary beneficiary. VIEs are entities in which the equity investors do not have sufficient equity at risk to finance their endeavors without additional financial support or that the holders of the equity investment at risk do not have a controlling financial interest. The primary beneficiary is defined by the entity having both of the following characteristics: (i) the power to direct those matters that most significantly impact the activities of the VIE and (ii) the obligation to absorb losses or the right to receive benefits of the VIE that could potentially be significant to the VIE. For entities that the Company has the obligations to fund losses, its maximum exposure to loss is not limited to the carrying amount of its investments.
Use of Estimates	Use of Estimates The preparation of financial statements in conformity with accounting principles generally accepted in the United States of America ("US GAAP") requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenue and expenses during the reporting period. Actual results could differ from those estimates.
Operating Properties	Operating Properties Operating properties are carried at historical cost less accumulated depreciation and impairment losses. The value of operating properties reflects their purchase price or development cost. Acquisition costs related to business combinations are expensed as incurred, whereas the costs related to asset acquisitions are capitalized as incurred. Costs incurred for the renovation and betterment of an operating property are capitalized to the Company’s investment in that property. Ordinary repairs and maintenance are expensed as incurred.
Purchase Price Allocation	Purchase Price Allocation For acquisitions of real estate or in-substance real estate that are accounted for as business combinations, we recognize the assets acquired (including the intangible value of acquired above- or below-market leases, acquired in-place leases and tenant relationship values), liabilities assumed, noncontrolling interests, and previously existing ownership interests at fair value as of the acquisition date. Any excess (deficit) of the consideration transferred relative to the fair value of the net assets acquired is accounted for as goodwill (bargain purchase gain). Acquisition costs related to business combinations are expensed as incurred. Acquisitions of real estate and in-substance real estate that do not meet the definition of a business are accounted for as asset acquisitions. The Company generally expects that acquisitions of real estate or in-substance real estate will not meet the definition of business and therefore are accounted for as asset acquisitions, unless specifically noted otherwise. The accounting model for asset acquisitions is similar to the accounting model for business combinations except that the acquisition consideration (including acquisition costs) is allocated to the individual assets acquired and liabilities assumed on a relative fair value basis. As a result, asset acquisitions do not result in recognition of goodwill or a bargain purchase gain. Additionally, because the accounting model for asset acquisitions is a cost accumulation model, preexisting interests in the acquired assets, if any, are not remeasured to fair value but continue to be accounted for at their historical cost. Direct acquisition costs are capitalized if an asset acquisition is probable. If we determine that an asset acquisition is no longer probable, no new costs are capitalized and all capitalized costs that are not recoverable are written off. The purchase price is allocated to the acquired assets and assumed liabilities, including land and buildings, as if vacant based on highest and best use for the acquired assets. The Company assesses and considers fair value of the operating properties based on estimated cash flow projections that utilize discount and/or capitalization rates that it deems appropriate, as well as available market information. Estimates of future cash flows are based on a number of factors including the historical operating results, known and anticipated trends, and market and economic conditions. The Company allocates the purchase price of properties considered to be business combinations and asset acquisitions to net tangible and identified intangible assets acquired based on fair values. Above-market and below-market in-place lease values for acquired properties are recorded based on the present value (using an interest rate which reflects the risks associated with the leases acquired) of the difference between (i) the contractual amounts to be paid pursuant to the in-place leases and (ii) the Company’s estimate of the fair market lease rates for the corresponding in-place leases, measured over a period equal to the remaining noncancellable term of the lease (including the below market fixed renewal periods that are considered probable, if applicable). Capitalized above-market lease values are amortized as a reduction of rental income over the remaining noncancellable terms of the respective leases. Capitalized below-market lease values are amortized as an increase to rental income over the remaining noncancellable terms of the respective leases, including any below market fixed-rate renewal option periods that are considered probable. Other intangible assets also include in-place leases based on the Company’s evaluation of the specific characteristics of each tenant’s lease and the Company’s overall relationship with the respective tenant. The Company estimates the cost to execute leases with terms similar to the remaining lease terms of the in-place leases, including leasing commissions, legal and other related expenses. This intangible asset is amortized to expense over the remaining term of the respective leases and any fixed-rate bargain renewal periods. Factors considered by the Company in this analysis include an estimate of the carrying costs during the expected lease-up periods considering current market conditions and costs to execute similar leases. In estimating carrying costs, the Company includes real estate taxes, insurance, and other operating expenses, and estimates of lost rents at market rates during the expected lease-up periods, which primarily range from four In the event that a tenant terminates its lease, the unamortized portion of each intangible, including in-place lease values and tenant relationship values, is charged to expense and market rate adjustments (above or below) are recorded to revenue.
Depreciation and Amortization	Depreciation and Amortization The costs of buildings and improvements are depreciated using the straight-line method based on the following useful lives: buildings and improvements (5 to 55 years) and tenant improvements (the shorter of (i) the life of the asset (1 to 16 years) or (ii) the lease term).
Construction-in-Progress	Construction-in-ProgressProject costs directly associated with the development or redevelopment and construction of a real estate project are capitalized as construction-in-progress. Construction-in-progress also includes costs related to ongoing tenant improvement projects. In addition, interest, real estate taxes, and other expenses that are directly associated with the Company’s development or redevelopment activities are capitalized beginning when activities necessary to ready the asset for its intended use are in progress and capital expenditures have been made and ending when the property is placed in service. Interest expense is capitalized using the Company’s weighted average interest rate. Internal direct costs are capitalized to projects in which qualifying expenditures are being incurred.
Ground Leases	Ground Leases The Company is the lessee under long-term ground leases classified as operating leases. The Company makes significant assumptions and judgments when determining the discount rate for the lease to calculate the present value of the lease payments. As the rate implicit in the lease is not readily determinable, the Company estimates the incremental borrowing rate (“IBR”) that it would need to pay to borrow, on a collateralized basis, an amount equal to the lease payments in a similar economic environment, over a similar lease term. The Company utilizes a market-based approach to estimate the IBR for each individual lease. The base IBR is estimated utilizing observable mortgage and corporate bond rates, which are then adjusted to account for considerations related to the Company’s credit rating and the lease term to select an incremental borrowing rate for each lease. The right of use assets and lease liabilities are presented as “Right of use asset - operating leases, net” and “Lease liability - operating leases”, respectively, on the consolidated balance sheet as of December 31, 2021 and 2020, respectively. The lease liabilities and right of use assets are amortized on a straight-line basis over the lease term with the corresponding expense classified in “Property operating expenses” on the consolidated statements of operations. The most recent CPI adjustment is used to determine the present value of the lease payments for an indexed lease and ultimately the right of use asset and corresponding lease liability. Rent payments for amounts in excess of this estimated growth rate will be expensed on a cash basis as incurred and are considered variable lease costs.
Impairment of Real Estate Investments	Impairment of Real Estate Investments The Company reviews its real estate investments for impairment following the end of each quarter for each of its real estate investments where events or changes in circumstances indicate that the carrying amounts may not be recoverable. The Company updates leasing and other assumptions regularly, paying particular attention to real estate investments where there is an event or change in circumstances that indicates an impairment in value. Additionally, the Company considers strategic decisions regarding the future development plans for real estate investment under development and other market factors. For real estate investments to be held and used, the Company analyzes recoverability based on the estimated undiscounted future cash flows expected to be generated from the operations and eventual disposition of the assets over, in most cases, a 10-year hold period. If there is significant possibility that the Company will dispose of assets earlier, it analyzes the recoverability using a probability weighted analysis of the undiscounted future cash flows expected to be generated from the operations and eventual disposition of each asset using various probable hold periods. If the recoverability analysis indicates that the carrying value of the tested real estate investment is not recoverable, the real estate investment is written down to its fair value and an impairment is recognized in the amount of the excess of the carrying amount of the asset over its fair value. If and when the Company’s plans change, it revises its recoverability analysis to use cash flows expected from operations and eventual disposition of each asset using hold periods that are consistent with its revised plans. Estimated future cash flows used in such analysis are based on the Company’s plans for the real estate investment and its views of market economic conditions. The estimates consider assumptions, including but not limited to market rental rates, capitalization rates, and recent sales data for comparable real estate investments. Future cash flows are discounted when
Assets Held for Sale	Assets Held for Sale The Company generally reclassifies assets to held for sale when the transaction has been approved by its Board of Trustees, or by officers vested with authority to approve the transaction, and there are no known significant contingencies relating to the sale of the real estate investment within one year of the consideration date and the consummation of the transaction is otherwise considered probable. When a real estate investment is designated as held for sale, the Company stops depreciating the real estate investment and estimates the real estate investment’s fair value, net of selling costs. If the determination is made that the estimated fair value, net of selling costs, is less than the net carrying value of the real estate investment, an impairment is recognized, reducing the net carrying value of the real estate investment to estimated fair value less selling costs. For periods in which a real estate investment is classified as held for sale, the Company classifies the assets and liabilities, as applicable, of the real estate investment as held for sale on the consolidated balance sheet for such periods.
Impairment of Land Held for Development	Impairment of Land Held for Development When demand for build-to-suit properties declines and the ability to sell land held for development deteriorates, or other market factors indicate possible impairment in the recoverability of land held for development, it is reviewed for impairment by comparing its fair value to its carrying value. If the estimated sales value is less than the carrying value, the carrying value is written down to its estimated fair value. Estimated fair value is generally determined using a market valuation approach, comparing the subject property to recent comparable market transactions in a similar location; or using estimated cash flows.
Cash and Cash Equivalents	Cash and Cash Equivalents Cash and cash equivalents are highly-liquid investments with original maturities of three months or less. The Company maintains cash equivalents in money market accounts with financial institutions in excess of insured limits, but believes this risk is mitigated by only investing in or through major financial institutions. The Company does not invest its available cash balances in money market funds. As such, available cash balances are appropriately reflected as cash and cash equivalents on the consolidated balance sheets.
Restricted Cash	Restricted Cash Restricted cash consists of cash held as collateral to provide credit enhancement for the Company’s mortgage debt, cash for property taxes, capital expenditures and tenant improvements. Restricted cash also includes cash held by qualified intermediaries for possible investments in like-kind exchanges in accordance with Section 1031 of the Internal Revenue Code in connection with sales of the Company’s properties. Restricted cash is included in “Other assets” in the consolidated balance sheets.
Accounts Receivable And Accrued Rent Receivable	Accounts Receivable and Accrued Rent Receivable Generally, leases with tenants are accounted for as operating leases. Minimum lease payments under tenant leases are recognized on a straight-line basis over the term of the related lease. The cumulative difference between lease revenue recognized under the straight-line method and contractual lease payment terms are recorded as “Accrued rent receivable, net” on the consolidated balance sheets. Included in current tenant receivables are tenant reimbursements which are comprised of amounts recoverable from tenants for common area maintenance expenses and certain other recoverable expenses that are recognized as revenue in the period in which the related expenses are incurred.
Investments in Unconsolidated Real Estate Ventures	Investments in Unconsolidated Real Estate Ventures Under the equity method, investments in real estate ventures are recorded initially at cost and subsequently adjusted for equity in earnings, contributions, distributions, and impairments. The Company generally allocates income and losses from the unconsolidated real estate ventures based on the venture's distribution priorities, which may be different from its stated ownership percentage. For real estate ventures that are constructing assets to commence planned principal operations, the Company capitalizes interest expense to the extent that it is recoverable using the Company’s weighted average interest rate of consolidated debt and its investment balance as a basis. Planned principal operations commence when a property is available to lease and at that point in time, the Company ceases capitalizing interest to its investment basis. At least quarterly, management assesses whether there are any other than temporary impairment indicators of the Company’s investments in real estate ventures. An investment is other than temporarily impaired only if the fair value of the investment in a real estate venture, as estimated by management, is less than the carrying value and the decline is other than temporary. To the extent that an other than temporary impairment has occurred, an impairment charge is recorded in the amount of the excess of the carrying amount of the investment over the estimated fair value. Management is required to make significant judgments about the estimated fair value of its investments to determine if an impairment exists. Fair value is generally determined through income valuation approaches, including discounted cash flows and direct capitalization models. When the Company acquires an interest in or contributes assets to a real estate venture project, the difference between the Company’s cost basis in the investment and the value of the real estate venture or asset contributed is amortized over the life of the related assets, intangibles, and liabilities and such adjustment is included in the Company’s share of equity in income of unconsolidated real estate ventures.
Deferred Costs	Deferred Costs Certain costs incurred in connection with property leasing are capitalized as deferred leasing costs. Deferred leasing costs consist primarily of third-party and internal leasing commissions that are amortized using the straight-line method over the life of the respective lease which generally ranges from 1 to 16 years. Management re-evaluates the remaining useful lives of leasing costs in conjunction with changes in the respective lease term.
Notes Receivable	Notes Receivable The Company accounts for notes receivable on its balance sheet at amortized cost, net of allowance for loan losses. Interest income is recognized over the term of the notes receivable and is calculated based on the contractual terms of each note agreement. At inception and on a quarterly basis, the Company evaluates notes receivable for the current estimate of expected credit losses over the contractual term using a probability-of-default method and reports in net income (as a credit loss expense) the amount necessary to adjust the allowance for credit losses to reflect management's current estimate. Management considers performance and/or value of the underlying collateral property as well as the financial and operating capability of the borrower/sponsor in its evaluation.
Deferred Financing Costs	Deferred Financing Costs Costs incurred in connection with debt financing are capitalized as a direct deduction from the carrying value of the debt, except for costs capitalized related to the Company’s unsecured credit facility, which are capitalized within the “Deferred costs, net” caption on the accompanying consolidated balance sheets. Deferred financing costs are charged to interest expense over the terms of the related debt agreements. Deferred financing costs consist primarily of loan fees which are amortized over the related loan term on a basis that approximates the effective interest method. Deferred financing costs are accelerated, when debt is extinguished, as part of the “Interest expense-amortization of deferred financing costs” caption within the Company’s consolidated statements of operations. Original issue discounts are recognized as part of the gain or loss on extinguishment of debt, as appropriate.
Revenue Recognition	Revenue Recognition Rental Revenue The Company generates revenue under leases with tenants occupying the Properties. Generally, leases with tenants are accounted for as operating leases. The operating leases have various expiration dates. As of December 31, 2021 and 2020, the Company did not have any leases classified as direct-financing or sales-type leases. Fixed lease payments under tenant leases, determined to be collectible, are recognized on a straight-line basis over the term of the related lease. The cumulative difference between lease revenue recognized under the straight-line method and contractual lease payments are recorded as “Accrued rent receivable” on the consolidated balance sheets. Variable lease payments are recognized as lease revenue in the period in which changes occur in facts and circumstances on which the variable lease payments are based. Topic 842 requires a binary approach to evaluating leases for collectability. Lessors are required to determine if it is probable that substantially all of the lease payments will be collected from the tenant over the lease term. Should the lessor determine that it is not probable that substantially all of the lease payments will be collected, the standard requires that the lessor write off any accrued rent receivable and begin recognizing lease payments on a cash basis. The Company’s lease revenue is impacted by the Company’s determination of whether improvements to the property, whether made by the Company or by the tenant, are landlord assets. The determination of whether an improvement is a landlord asset requires judgment. In making this judgment, the Company’s primary consideration is whether an improvement would be utilizable by another tenant upon the then-existing tenant vacating the improved space. If the Company has funded an improvement that it determines not to be landlord assets, then it treats the cost of the improvement as a lease incentive. If the tenant has funded an improvement that the Company determines to be landlord assets, then the Company treats the costs of the improvement as deferred revenue and amortizes these costs into revenue over the lease term. For certain leases, the Company also makes significant assumptions and judgments in determining the lease term, including assumptions when the lease provides the tenant with an early termination option or purchase option. The lease term impacts the period over which the Company determines and records lease payments and also impacts the period over which it amortizes lease-related costs. The Company considers all relevant factors that create an economic incentive for the lessee and uses judgment to determine if those factors, considered together, signify that the lessee is reasonably certain to exercise the option. For leases where a tenant executes a lease termination, termination fees are generally recognized over the modified term of the lease as rental income. Additionally, any deferred rents receivable are accelerated over the modified lease term. The Company’s leases also typically provide for tenant reimbursement of a portion of common area maintenance expenses and other operating expenses to the extent that a tenant’s pro rata share of expenses exceeds a base year level set in the lease or to the extent that the tenant has a lease on a triple net basis. As the timing and pattern of revenue recognition is the same, rents and tenant reimbursements are treated as a combined lease component and included in the "Rents" caption within the Company's consolidated statements of operations. Fixed lease payments include contractual rents under lease agreements with tenants recognized on a straight-line basis over the lease term, including amortization of lease incentives and above or below market rent intangibles, and parking income that is fixed under a long-term contract. Variable lease payments include reimbursements billed to tenants, termination fees, bad debt expense, and parking income that is not fixed under a long-term contract. Point of Sale Revenue Point of sale revenue consists of parking, restaurant, and flexible stay revenue from the Company’s hotel operations. Point of sale service obligations are performed daily, and the customer obtains control of those services simultaneously as they are performed. Accordingly, revenue is recorded on an accrual basis as it is earned, coinciding with the services that are provided to the Company’s customers. Parking and flexible stay revenue is recognized within rents and restaurant income is recognized within other income on the consolidated statements of operations. Third party management fees, labor reimbursement, and leasing The Company performs property management services for its managed real estate ventures and third-party property owners of real estate that consist of: (i) providing leasing services, (ii) property inspections, (iii) repairs and maintenance monitoring, and (iv) financial and accounting oversight. For these services, the Company earns management fees monthly, which are based on a fixed percentage of each managed property’s financial results, and is reimbursed for the labor costs incurred by its property management employees as services are rendered to the property owners. The Company determined that control over the services is passed to its customers simultaneously as performance occurs. Accordingly, management fee revenue is earned as the services are provided to the Company’s customers. Lease commissions are earned when the Company, as a broker for the third party property owner, executes a lease agreement with a tenant. Based on the terms of the Company’s lease commission contracts, the Company's performance obligation to the customer has been completed upon execution of each lease agreement. The Company’s lease commissions are earned based on a fixed percentage of rental income generated for each executed lease agreement and there is no variable income component. Development fee revenue is earned through two different sources: (i) the Company performs development services for third parties as an agent and earns fixed development fees based on a percentage of construction costs incurred over the construction period, and (ii) the Company acts as a general contractor on behalf of one of its managed real estate ventures. The Company acts as the principal construction company for the real estate ventures and records gross revenue as it provides construction services based on the quantifiable construction outputs. In applying the cost based output method of revenue recognition, the Company uses the actual costs incurred relative to the total estimated costs to determine its progress towards contract completion and to calculate the corresponding gross revenue and gross profit to recognize. For any costs that do not contribute to satisfying the Company’s performance obligations, it excludes such costs from its output methods of revenue recognition as the amounts are not reflective of transferring control of the outputs to the customer. The use of estimates in this calculation involves significant judgment.
Income Taxes	Income Taxes Parent Company The Parent Company has elected to be treated as a REIT under Sections 856 through 860 of the Internal Revenue Code of 1986, as amended (the “Code”). In order to continue to qualify as a REIT, the Parent Company is required to, among other things, distribute at least 90% of its annual REIT taxable income to its shareholders and meet certain tests regarding the nature of its income and assets. As a REIT, the Parent Company is not subject to federal and state (in states that follow federal rules) income taxes with respect to the portion of its income that meets certain criteria and is distributed annually to its shareholders. Accordingly, a nominal provision for federal and state (as applicable) income taxes is included in the accompanying consolidated financial statements with respect to the operations of the Parent Company. The Parent Company intends to continue to operate in a manner that allows it to meet the requirements for taxation as a REIT. If the Parent Company fails to qualify as a REIT in any taxable year, it will be subject to federal and state (as applicable) income taxes and may not be able to qualify as a REIT for the four tax years following the year in which it first failed to qualify. The Parent Company is subject to certain local income taxes. Provision for federal income taxes is recorded in the income tax provision line item and state and local income taxes have been included in operating expenses in the Parent Company’s consolidated statements of operations. The Parent Company is subject to a 4% federal excise tax if sufficient taxable income is not distributed within prescribed time limits. The excise tax equals 4% of the annual amount, if any, by which the sum of (a) 85% of the Parent Company’s ordinary income and (b) 95% of the Parent Company’s net capital gain exceeds cash distributions and certain taxes paid by the Parent Company. No excise tax was incurred in 2021, 2020 or 2019. The Parent Company has elected to treat several of its subsidiaries as taxable REIT subsidiaries (each a “TRS”). A TRS is subject to federal, state and local income tax. In general, a TRS may perform non-customary services for tenants, hold assets that the Parent Company, as a REIT, cannot hold directly and generally may engage in any real estate or non-real estate related business. The Company’s taxable REIT subsidiaries did not have material tax provisions or deferred income tax items as of December 31, 2021 and December 31, 2020. Operating Partnership In general, the Operating Partnership is not subject to federal and state income taxes, and accordingly, no provision for income taxes has been made in the accompanying consolidated financial statements. The partners of the Operating Partnership are required to include their respective share of the Operating Partnership’s profits or losses in their respective tax returns. The Operating Partnership’s tax returns and the amount of allocable partnership profits and losses are subject to examination by federal and state taxing authorities. For any year beginning on or after January 1, 2017, the Operating Partnership can be assessed with federal income tax in the course of an audit by the IRS. Under the partnership audit rules included in the Bipartisan Budget Act of 2015, the Operating Partnership has the option to make a push-out election and allocate the partnership adjustments to all the former partners for the tax year under audit. The Operating Partnership may elect to treat a subsidiary REIT under Sections 856 through 860 of the Code, if applicable. Each subsidiary REIT would be required to meet the requirements for treatment as a REIT under Sections 856 through 860 of the Code. If a subsidiary REIT fails to qualify as a REIT in any taxable year, that subsidiary REIT would be subject to federal and state income taxes and would not be able to qualify as a REIT for the four subsequent taxable years. Also, each subsidiary REIT would be subject to certain local income taxes. The Operating Partnership has elected to treat several of its subsidiaries as TRSs, which are subject to federal, state and local income tax.
Earnings Per Share	Earnings Per Share Basic earnings per share (“EPS”) is computed by dividing net income available to common shareholders, as adjusted for unallocated earnings, if any, of certain securities, by the weighted average number of common shares outstanding during the year. Diluted EPS reflects the potential dilution that could occur from common shares issuable in connection with awards under share-based compensation plans, including upon the exercise of stock options, and conversion of the noncontrolling interests in the Operating Partnership. Anti-dilutive shares are excluded from the calculation. Earnings Per Unit Basic earnings per unit is computed by dividing net income available to common unitholders, as adjusted for unallocated earnings, if any, of certain securities issued by the Operating Partnership, by the weighted average number of common unit equivalents outstanding during the year. Diluted earnings per unit reflects the potential dilution that could occur from units issuable in connection with awards under share-based compensation plans, including upon the exercise of stock options. Anti-dilutive units are excluded from the calculation.
Share-Based Compensation Plans	Share-Based Compensation PlansThe Parent Company maintains a shareholder-approved equity-incentive plan known as the Amended and Restated 1997 Long-Term Incentive Plan (the “1997 Plan”). The 1997 Plan is administered by the Compensation Committee of the Parent Company’s Board of Trustees. Under the 1997 Plan, the Compensation Committee is authorized to award equity and equity-based awards, including incentive stock options, non-qualified stock options, restricted share rights and performance-based share units.
Comprehensive Income	Comprehensive Income Comprehensive income is recorded in accordance with the provisions of the accounting standard for comprehensive income. The accounting standard establishes standards for reporting comprehensive income and its components in the financial statements. Comprehensive income includes the effective portions of changes in the fair value of derivatives.
Accounting for Derivative Instruments and Hedging Activities	Accounting for Derivative Instruments and Hedging Activities The Company accounts for its derivative instruments and hedging activities in accordance with the accounting standard for derivative and hedging activities. The accounting standard requires the Company to measure every derivative instrument (including certain derivative instruments embedded in other contracts) at fair value and record them on the balance sheet as either an asset or liability. See disclosures below related to the accounting standard for fair value measurements and disclosures. For derivatives designated as cash flow hedges, the effective portions of changes in the fair value of the derivative are reported in other comprehensive income while the ineffective portions are recognized in earnings. The Company actively manages its ratio of fixed-to-floating rate debt. To manage its fixed and floating rate debt in a cost-effective manner, the Company, from time to time, enters into interest rate swap agreements as cash flow hedges, under which it agrees to exchange various combinations of fixed and/or variable interest rates based on agreed upon notional amounts.
Fair Value Measurements	Fair Value Measurements The Company estimates the fair value of its derivatives in accordance with the accounting standard for fair value measurements and disclosures. The accounting standard defines fair value as the exchange price that would be received for an asset or paid to transfer a liability (an exit price) in the principal or most advantageous market for the asset or liability in an orderly transaction between market participants on the measurement date. It also establishes a fair value hierarchy which requires an entity to maximize the use of observable inputs and minimize the use of unobservable inputs when measuring fair value. The standard describes three levels of inputs that may be used to measure fair value. Financial assets and liabilities recorded on the consolidated balance sheets are categorized based on the inputs to the valuation techniques as follows: • Level 1 inputs are quoted prices (unadjusted) in active markets for identical assets or liabilities that the Company has the ability to access; • Level 2 inputs are inputs, other than quoted prices included in Level 1, which are observable for the asset or liability, either directly or indirectly. Level 2 inputs may include quoted prices for similar assets and liabilities in active markets, as well as inputs that are observable for the asset or liability (other than quoted prices), such as interest rates, foreign exchange rates, and yield curves that are observable at commonly quoted intervals; and • Level 3 inputs are unobservable inputs for the asset or liability, which is typically based on an entity’s own assumptions, as there is little if any, related market activity or information. In instances where the determination of the fair value measurement is based on inputs from different levels of the fair value hierarchy, the level in the fair value hierarchy within which the entire fair value measurement falls is based on the lowest level input that is significant to the fair value measurement in its entirety. The Company’s assessment of the significance of a particular input to the fair value measurement in its entirety requires judgment, and considers factors specific to the asset or liability.
Risks And Uncertainties - COVID-19	Risks and Uncertainties - COVID-19 Currently, one of the most significant risks and uncertainties the Company faces is the potential adverse effect of the ongoing global COVID-19 pandemic, which has significantly slowed global economic activity and caused significant volatility in financial markets, causing many to fear a global recession. The responses of many countries, including the U.S., have included mandatory quarantines, restrictions on business activities, including construction activities, restrictions on group gatherings, restrictions on travel and mandatory closures. These actions have disrupted the global economy and supply chains and adversely impacted many industries, including owners and developers of real estate. Moreover, there is significant uncertainty around the breadth and duration of business disruptions related to the COVID-19 pandemic, as well as its impact on the U.S. economy and consumer confidence. Demand for space at the Company's properties is dependent on a variety of macroeconomic factors, such as employment levels, interest rates, changes in stock market valuations, rent levels and availability of competing space. The extent to which the COVID-19 pandemic impacts the Company's results will depend on
Recent Accounting Pronouncements	Recent Accounting Pronouncements In March 2020, the FASB issued ASU 2020-04 Reference Rate Reform (Topic 848) Facilitation of the Effects of Reference Rate Reform on Financial Reporting. The amendments provide practical expedients for reference rate reform related activities that impact debt, leases, derivatives and other contracts. The guidance is optional and is effective between March 12, 2020 and December 31, 2022. The guidance may be elected over time as reference rate reform activities occur. The Company continues to evaluate the impact of the guidance and may apply elections as applicable as additional changes in the market occur.

ORGANIZATION OF THE PARENT CO_2

ORGANIZATION OF THE PARENT COMPANY AND THE OPERATING PARTNERSHIP (Tables)	12 Months Ended
	Dec. 31, 2021
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Summary of Core Portfolio of Operating Properties and Excludes Development, Redevelopment and Held for Sale	The Company’s core portfolio of operating properties (the “Core Properties”) excludes development properties, redevelopment properties, and properties held for sale. The Properties were comprised of the following as of December 31, 2021: Number of Properties Rentable Square Feet Office properties 72 12,097,300 Mixed-use properties 5 942,334 Core Properties 77 13,039,634 Development property 1 205,803 Redevelopment properties 3 432,699 The Properties 81 13,678,136

SUMMARY OF SIGNIFICANT ACCOUN_3

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Tables)	12 Months Ended
	Dec. 31, 2021
Accounting Policies [Abstract]
Disaggregation of Revenue	The following is a summary of revenue earned by the Company’s reportable segments (see Note 19, ''Segment Information,” for further information) during the year ended December 31, 2021 (in thousands): Philadelphia CBD Pennsylvania Suburbs Austin, Texas Metropolitan Washington, D.C. Other Corporate (a) Total Fixed rent $ 149,441 $ 113,748 $ 62,545 $ 12,410 $ 8,020 $ (2,240) $ 343,924 Variable rent 41,585 10,358 34,850 646 2,660 (257) 89,842 Total lease revenue 191,026 124,106 97,395 13,056 10,680 (2,497) 433,766 Amortization of deferred market rents 2,064 (9) 3,322 — — — 5,377 Daily parking & hotel flexible stay 11,758 159 109 117 233 — 12,376 Total rents 204,848 124,256 100,826 13,173 10,913 (2,497) 451,519 Third party management fees, labor reimbursement and leasing 893 34 452 6,548 3,077 15,440 26,444 Other income 2,117 276 402 144 25 5,892 8,856 Total revenue $ 207,858 $ 124,566 $ 101,680 $ 19,865 $ 14,015 $ 18,835 $ 486,819 The following is a summary of revenue earned by the Company’s reportable segments (see Note 19, ''Segment Information,” for further information) during the year ended December 31, 2020 (in thousands): Philadelphia CBD Pennsylvania Suburbs Austin, Texas Metropolitan Washington, D.C. Other Corporate (a) Total Fixed rent $ 166,286 $ 128,044 $ 63,366 $ 29,830 $ 8,064 $ (2,412) $ 393,178 Variable rent 51,410 12,951 35,123 3,544 2,401 (1,343) 104,086 Total lease revenue 217,696 140,995 98,489 33,374 10,465 (3,755) 497,264 Amortization of deferred market rents 1,146 (12) 3,531 — 203 — 4,868 Daily parking & hotel flexible stay 10,777 179 49 135 232 — 11,372 Total rents 229,619 141,162 102,069 33,509 10,900 (3,755) 513,504 Third party management fees, labor reimbursement and leasing 927 39 689 6,541 2,560 7,824 18,580 Other income 1,482 412 224 173 9 468 2,768 Total revenue $ 232,028 $ 141,613 $ 102,982 $ 40,223 $ 13,469 $ 4,537 $ 534,852 The following is a summary of revenue earned by the Company’s reportable segments (see Note 19, ''Segment Information,” for further information) during the year ended December 31, 2019 (in thousands): Philadelphia CBD Pennsylvania Suburbs Austin, Texas Metropolitan Washington, D.C. Other Corporate (a) Total Fixed rent $ 178,481 $ 125,969 $ 62,232 $ 39,420 $ 7,834 $ (2,412) $ 411,524 Variable rent 58,580 14,282 34,748 4,029 3,080 (495) 114,224 Total lease revenue 237,061 140,251 96,980 43,449 10,914 (2,907) 525,748 Amortization of deferred market rents 3,745 (12) 4,638 — 486 — 8,857 Daily parking & hotel flexible stay 18,665 174 165 824 232 — 20,060 Total rents 259,471 140,413 101,783 44,273 11,632 (2,907) 554,665 Third party management fees, labor reimbursement and leasing 876 43 1,956 6,922 2,915 6,914 19,626 Other income 3,422 628 418 303 11 1,344 6,126 Total revenue $ 263,769 $ 141,084 $ 104,157 $ 51,498 $ 14,558 $ 5,351 $ 580,417 (a) Corporate includes intercompany eliminations necessary to reconcile to consolidated Company totals.

REAL ESTATE INVESTMENTS (Tables

REAL ESTATE INVESTMENTS (Tables)	12 Months Ended
	Dec. 31, 2021
Real Estate [Abstract]
Gross Carrying Value of Operating Properties	As of December 31, 2021 and 2020, the gross carrying value of the operating properties was as follows (in thousands): December 31, 2021 December 31, 2020 Land $ 410,144 $ 407,514 Building and improvements 2,653,492 2,665,232 Tenant improvements 408,966 401,363 Total $ 3,472,602 $ 3,474,109
Capitalized Construction Costs	The following table shows the amount of compensation costs (including bonuses and benefits) capitalized for the years presented (in thousands): December 31, 2021 2020 2019 Development $ 4,815 $ 4,802 $ 3,047 Redevelopment 1,170 543 775 Tenant Improvements 1,917 3,021 3,609 Total $ 7,902 $ 8,366 $ 7,431
Schedule of Acquisitions	The following table summarizes the property acquisitions during the year ended December 31, 2020 (dollars in thousands): Property/Portfolio Name Acquisition Date Location Property Type Rentable Square Feet/Acres Purchase Price (a) 145 King of Prussia Road February 27, 2020 Radnor, PA Land 7.75 acres $ 11,250 1505-11 Race Street November 5, 2020 Philadelphia, PA Office 119,763 $ 9,700 250 King of Prussia Road (b) November 30, 2020 Radnor, PA Office 169,843 $ 20,250 (a) Exclusive of transaction costs and price adjustments. See purchase price allocation table below for a breakout of the net purchase price for wholly owned properties. (b) This property was placed into redevelopment and is therefore included within Construction-in-progress on the consolidated balance sheets.
Schedule of Asset Acquisition	The acquisition values have been allocated as follows (in thousands): 1505-11 Race Street Building, land and improvements $ 9,723 Intangible assets acquired 2,422 Below market lease liabilities assumed (2,193) Total unencumbered acquisition value 9,952 Amortization period of intangible assets 1.5 years Amortization period of below market liabilities assumed 1.5 years
Summary of Properties Sold	The following table summarizes the property dispositions during the years ended December 31, 2021, 2020 and 2019 (dollars in thousands): Property/Portfolio Name Disposition Date Location Property Type Rentable Square Feet/Acres Sales Price Gain/(Loss) on Sale (a) 1100 Lenox Drive September 8, 2021 Lawrenceville, NJ Land 5.0 acres $ 2,575 $ 68 2100-2200 Lenox Drive July 6, 2021 Lawrenceville, NJ Land 35.2 acres $ 8,900 $ 842 Mid-Atlantic Office Portfolio (b) (d) December 21, 2020 Various Office 1,128,645 $ 192,943 $ 15,164 One and Two Commerce Square (c) July 21, 2020 Philadelphia, PA Office 1,896,142 $ 115,000 $ 271,905 Keith Valley June 15, 2020 Horsham, PA Land 14.0 Acres $ 4,000 $ 201 52 East Swedesford Road March 19, 2020 Malvern, PA Office 131,077 $ 18,000 $ 2,336 1900 Gallows Rd September 11, 2019 Vienna, VA Office 210,632 $ 36,400 $ (367) 9 Presidential Boulevard March 15, 2019 Bala Cynwyd, PA Land 2.7 Acres $ 5,325 $ 751 (a) Gain/(Loss) on Sale is net of closing and other transaction related costs. (b) The Company sold a 60% equity interest in a portfolio of twelve suburban office properties containing an aggregate of 1.1 million square feet ("Mid-Atlantic Office Portfolio"), nine of which are located in the Pennsylvania suburbs and three of which are located in Maryland, to an unrelated third party for a gross sales price of $192.9 million. The transaction resulted in deconsolidation of the properties and formation of PA/MD NNN Office JV, LLC ("Mid-Atlantic Office JV"). The Company recorded its investment at fair value and recognized a gain of $15.2 million in "Net gain on disposition of real estate" on the consolidated statements of operations. See Note 4, ''Investment in Unconsolidated Real Estate Ventures," for further information. (c) The Company sold a 30% preferred equity interest in two office buildings located in Philadelphia, Pennsylvania, to an unrelated third party for $115.0 million (the "Commerce Square Venture Transaction"), which resulted in deconsolidation of the properties and formation of Brandywine Commerce I LP and Brandywine Commerce II LP (collectively, the "Commerce Square Venture"). The transaction valued the properties at $600.0 million. The Company recorded its investment at fair value and recognized a gain of $271.9 million in "Net gain on disposition of real estate" on the consolidated statements of operations. See Note 4, ''Investment in Unconsolidated Real Estate Ventures," for further information. (d) The sales price includes $4.1 million of variable consideration held in escrow that will be released to the Company over a six

INVESTMENT IN UNCONSOLIDATED _2

INVESTMENT IN UNCONSOLIDATED REAL ESTATE VENTURES (Tables)	12 Months Ended
	Dec. 31, 2021
Equity Method Investments and Joint Ventures [Abstract]
Summary of Financial Position of Real Estate Ventures	The Company’s investment in the unconsolidated real estate ventures as of December 31, 2021 and 2020, and the Company’s share of the unconsolidated real estate ventures’ income (loss) for the years ended December 31, 2021 and 2020 was as follows (in thousands): Ownership Percentage Carrying Amount Company's Share of unconsolidated real estate venture Income (Loss) Unconsolidated Real Estate Venture Debt at 100%, gross 2021 2020 2021 2020 2019 2021 2020 Office Properties Commerce Square Venture 70% (a) $ 247,798 $ 253,128 $ (15,501) $ (9,150) — $ 213,069 $ 219,168 Mid-Atlantic Office Venture 40% (a) 31,680 32,996 932 96 — 123,015 120,831 Brandywine - AI Venture LLC 50% — 10,302 (721) 185 (2,800) — — Herndon Innovation Center Metro Portfolio Venture, LLC 15% 15,844 16,019 (174) (358) (498) 207,302 207,302 MAP Venture 50% (24,396) (11,516) (8,683) (6,570) (6,102) 184,263 185,000 PJP VII 25% (b) — — — — 190 — — PJP II 30% (b) — — — — 81 — — PJP VI 25% (b) — — — — (185) — — Other 4040 Wilson Venture (c) 50% 31,059 34,454 (2,258) (2,162) (368) 145,000 141,857 1919 Venture 50% 13,791 15,434 427 59 328 88,860 88,860 Development Properties 3025 JFK Venture 55% 56,370 — (118) — — — — JBG - 51 N Street (c) 70% 21,213 21,237 (402) (457) (313) — — JBG - 1250 First Street Office (c) 70% 17,751 17,757 (199) (227) (255) — — $ 411,110 $ 389,811 $ (26,697) $ (18,584) (9,922) $ 961,509 $ 963,018 (a) Ownership percentage represents the Company’s combined interest including preferred and common equity holdings. See "Commerce Square Venture" and "Mid-Atlantic Office JV" sections below for more information. (b) On October 29, 2019, the Company sold its interest in PJP II, PJP VI and PJP VII. See "PJP Ventures" section below for more information on the disposal. (c) This entity is a VIE. The following is a summary of the financial position of the unconsolidated real estate ventures in which the Company held interests as of December 31, 2021 and December 31, 2020 (in thousands): December 31, 2021 December 31, 2020 Net property $ 1,563,263 $ 1,520,804 Other assets 434,687 488,805 Other liabilities 331,947 333,049 Debt, net 956,668 956,688 Equity (a) 709,335 719,872 (a) This amount does not include the effect of the basis difference between the Company's historical cost basis and the basis recorded at the real estate venture level, which is typically amortized over the life of the related assets and liabilities. Basis differentials occur from the impairment of investments, purchases of third party interests in existing real estate ventures and upon the transfer of assets that were previously owned by the Company into a real estate venture. In addition, certain acquisition, transaction and other costs may not be reflected in the net assets at the real estate venture level.
Investment in Real Estate Ventures and Share of Real Estate Ventures' Income (Loss)	The following is a summary of results of operations of the unconsolidated real estate ventures in which the Company held interests during the twelve-month periods ended December 31, 2021, 2020 and 2019 (in thousands): Year Ended December 31, 2021 2020 2019 Revenue $ 214,792 $ 150,276 $ 132,358 Operating expenses (117,273) (85,812) (71,784) Interest expense, net (30,569) (22,661) (21,908) Depreciation and amortization (97,147) (70,805) (53,331) Provision for impairment (1,393) — (5,664) Loss on early extinguishment of debt — — (1,231) Net loss $ (31,590) $ (29,002) $ (21,560) Ownership interest % Various Various Various Company's share of net loss $ (25,972) $ (18,540) $ (9,865) Basis adjustments and other (725) (44) (57) Equity in loss of unconsolidated real estate ventures $ (26,697) $ (18,584) $ (9,922)
Schedule of Maturities of Long-term Debt	As of December 31, 2021, the aggregate principal payments of the unconsolidated real estate ventures recourse and non-recourse debt payable to third-parties are as follows (in thousands): 2022 $ 8,543 2023 477,649 2024 330,317 2025 — 2026 145,000 Thereafter — Total principal payments 961,509 Net deferred financing costs (5,923) Net original issue premium 1,082 Outstanding indebtedness $ 956,668 As of December 31, 2021, the aggregate scheduled principal payments on the Company's debt obligations were as follows (in thousands): 2022 $ 273,000 2023 350,000 2024 350,000 2025 — 2026 — Thereafter 878,610 Total principal payments 1,851,610 Net unamortized premiums/(discounts) 8,187 Net deferred financing costs (6,211) Outstanding indebtedness $ 1,853,586

LEASES (Tables)

LEASES (Tables)	12 Months Ended
	Dec. 31, 2021
Leases [Abstract]
Operating Lease Future Contractual Lease Payments	The Company leases properties to tenants under operating leases with various expiration dates. Future contractual lease payments under operating leases at December 31, 2021 are as follows (in thousands): Year 2022 $ 328,553 2023 327,981 2024 304,240 2025 274,216 2026 249,045 Thereafter 952,898
Lease Costs	The table below summarizes the Company’s operating lease cost (in thousands) recognized through “Property operating expenses” on the consolidated statements of operations (in thousands): Year Ended December 31, Lease Cost 2021 2020 Fixed lease cost $ 2,100 $ 2,100 Variable lease cost 43 45 Total $ 2,143 $ 2,145 Weighted-average remaining lease term (years) 55.2 55.9 Weighted-average discount rate 6.3 % 6.3 %
Operating Lease Liability Maturities	Lease payments on noncancellable leases at December 31, 2021 are as follows (in thousands): Year Minimum Rent 2022 $ 1,248 2023 1,263 2024 1,305 2025 1,321 2026 1,338 Thereafter 107,793 Total lease payments $ 114,268 Less: Imputed interest 91,306 Present value of operating lease liabilities $ 22,962

DEFERRED COSTS (Tables)

DEFERRED COSTS (Tables)	12 Months Ended
	Dec. 31, 2021
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure	As of December 31, 2021 and 2020, the Company’s deferred costs were comprised of the following (in thousands): December 31, 2021 Total Cost Accumulated Amortization Deferred Costs, net Leasing costs $ 143,895 $ (57,445) $ 86,450 Financing costs - Unsecured Credit Facility 6,299 (5,887) 412 Total $ 150,194 $ (63,332) $ 86,862 December 31, 2020 Total Cost Accumulated Amortization Deferred Costs, net Leasing costs $ 139,207 $ (55,656) $ 83,551 Financing costs - Unsecured Credit Facility 6,299 (4,994) 1,305 Total $ 145,506 $ (60,650) $ 84,856

INTANGIBLE ASSETS AND LIABILI_2

INTANGIBLE ASSETS AND LIABILITIES (Tables)	12 Months Ended
	Dec. 31, 2021
Goodwill and Intangible Assets Disclosure [Abstract]
Summary of Intangible Assets and Liabilities	As of December 31, 2021 and 2020, the Company’s intangible assets/liabilities were comprised of the following (in thousands): December 31, 2021 Total Cost Accumulated Amortization Intangible Assets, net Intangible assets, net: In-place lease value $ 72,376 $ (44,066) $ 28,310 Tenant relationship value 167 (97) 70 Above market leases acquired 486 (310) 176 Total intangible assets, net $ 73,029 $ (44,473) $ 28,556 Total Cost Accumulated Amortization Intangible Liabilities, net Intangible liabilities, net: Below market leases acquired $ 27,025 $ (14,044) $ 12,981 December 31, 2020 Total Cost Accumulated Amortization Intangible Assets, net Intangible assets, net: In-place lease value $ 91,552 $ (43,400) $ 48,152 Tenant relationship value 2,091 (1,938) 153 Above market leases acquired 530 (265) 265 Total intangible assets, net $ 94,173 $ (45,603) $ 48,570 Total Cost Accumulated Amortization Intangible Liabilities, net Intangible liabilities, net: Below market leases acquired $ 31,263 $ (12,815) $ 18,448
Summary of Amortization for Intangible Assets and Liabilities	As of December 31, 2021, the Company’s annual amortization for its intangible assets/liabilities, assuming no prospective early lease terminations, was as follows (dollars in thousands): Assets Liabilities 2022 $ 9,642 $ 2,588 2023 6,724 1,540 2024 4,433 1,321 2025 3,255 1,044 2026 1,195 754 Thereafter 3,307 5,734 Total $ 28,556 $ 12,981

DEBT OBLIGATIONS (Tables)

DEBT OBLIGATIONS (Tables)	12 Months Ended
	Dec. 31, 2021
Debt Disclosure [Abstract]
Consolidated Debt Obligations	The following table sets forth information regarding the Company’s consolidated debt obligations outstanding as of December 31, 2021 and 2020 (in thousands): December 31, 2021 December 31, 2020 Effective Maturity UNSECURED DEBT $600 million Unsecured Credit Facility $ 23,000 $ — LIBOR + 1.10% July 2022 (a) Seven 250,000 250,000 2.87% October 2022 $350.0M 3.95% Guaranteed Notes due 2023 350,000 350,000 3.87% February 2023 $350.0M 4.10% Guaranteed Notes due 2024 350,000 350,000 3.78% October 2024 $450.0M 3.95% Guaranteed Notes due 2027 450,000 450,000 4.03% November 2027 $350.0M 4.55% Guaranteed Notes due 2029 350,000 350,000 4.30% October 2029 Indenture IA (Preferred Trust I) 27,062 27,062 LIBOR + 1.25% March 2035 Indenture IB (Preferred Trust I) 25,774 25,774 LIBOR + 1.25% April 2035 Indenture II (Preferred Trust II) 25,774 25,774 LIBOR + 1.25% July 2035 Principal balance outstanding 1,851,610 1,828,610 Plus: original issue premium (discount), net 8,187 10,137 Less: deferred financing costs (6,211) (8,152) Total unsecured indebtedness $ 1,853,586 $ 1,830,595
Schedule of Maturities of Long-term Debt	As of December 31, 2021, the aggregate principal payments of the unconsolidated real estate ventures recourse and non-recourse debt payable to third-parties are as follows (in thousands): 2022 $ 8,543 2023 477,649 2024 330,317 2025 — 2026 145,000 Thereafter — Total principal payments 961,509 Net deferred financing costs (5,923) Net original issue premium 1,082 Outstanding indebtedness $ 956,668 As of December 31, 2021, the aggregate scheduled principal payments on the Company's debt obligations were as follows (in thousands): 2022 $ 273,000 2023 350,000 2024 350,000 2025 — 2026 — Thereafter 878,610 Total principal payments 1,851,610 Net unamortized premiums/(discounts) 8,187 Net deferred financing costs (6,211) Outstanding indebtedness $ 1,853,586

FAIR VALUE OF FINANCIAL INSTR_2

FAIR VALUE OF FINANCIAL INSTRUMENTS (Tables)	12 Months Ended
	Dec. 31, 2021
Fair Value Disclosures [Abstract]
Schedule of Financial Instruments With Fair Values Different From Their Carrying Amount	The following are financial instruments for which the Company’s estimates of fair value differ from the carrying amounts (in thousands): December 31, 2021 December 31, 2020 Carrying Amount (a) Fair Value Carrying Amount (a) Fair Value Unsecured notes payable $ 1,502,368 $ 1,588,780 $ 1,502,901 $ 1,607,310 Variable rate debt $ 351,218 $ 344,754 $ 327,694 $ 308,838 Notes receivable (b) $ 44,430 $ 45,230 $ 94,430 $ 97,372 (a) Net of deferred financing costs of $5.8 million and $7.2 million for unsecured notes payable, $0.4 million and $0.9 million for variable rate debt as of December 31, 2021 and December 31, 2020, respectively. (b) For further detail, refer to Note 5, ''Debt and Preferred Equity Investments.”

DERIVATIVE FINANCIAL INSTRUME_2

DERIVATIVE FINANCIAL INSTRUMENTS (Tables)	12 Months Ended
	Dec. 31, 2021
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Schedule of Derivative Instruments in Statement of Financial Position, Fair Value	The following table summarizes the terms and fair values of the Company’s derivative financial instruments as of December 31, 2021 and December 31, 2020. The notional amounts provide an indication of the extent of the Company’s involvement in these instruments at that time but do not represent exposure to credit, interest rate or market risks (amounts presented in thousands). Hedge Product Hedge Type Designation Notional Amount Strike Trade Date Maturity Date Fair value 12/31/2021 12/31/2020 12/31/2021 12/31/2020 Liabilities Swap Interest Rate Cash Flow (a) $ 250,000 $ 250,000 2.868 % October 8, 2015 October 8, 2022 $ (2,461) $ (6,627) Swap Interest Rate Cash Flow (b) — 25,774 3.300 % December 22, 2011 January 30, 2021 — (120) $ 250,000 $ 275,774 (a) Hedging unsecured variable rate debt. (b) On January 30, 2021, the interest rate hedge contract for this swap expired.

BENEFICIARIES' EQUITY OF THE _2

BENEFICIARIES' EQUITY OF THE PARENT COMPANY (Tables)	12 Months Ended
	Dec. 31, 2021
Equity [Abstract]
Earnings Per Share (EPS), Basic and Diluted	The following table details the number of shares and net income used to calculate basic and diluted earnings per share (in thousands, except share and per share amounts; results may not add due to rounding): Year Ended December 31, 2021 2020 2019 Basic Diluted Basic Diluted Basic Diluted Numerator Net income $ 12,366 $ 12,366 $ 307,326 $ 307,326 $ 34,529 $ 34,529 Net income attributable to noncontrolling interests (77) (77) (1,799) (1,799) (262) (262) Nonforfeitable dividends allocated to unvested restricted shareholders (421) (421) (410) (410) (396) (396) Net income attributable to common shareholders $ 11,868 $ 11,868 $ 305,117 $ 305,117 $ 33,871 $ 33,871 Denominator Weighted-average shares outstanding 170,878,185 170,878,185 171,926,079 171,926,079 176,132,941 176,132,941 Contingent securities/Share based compensation — 1,395,055 — 390,997 — 553,872 Weighted-average shares outstanding 170,878,185 172,273,240 171,926,079 172,317,076 176,132,941 176,686,813 Earnings per Common Share: Net income attributable to common shareholders $ 0.07 $ 0.07 $ 1.77 $ 1.77 $ 0.19 $ 0.19 The following table details the number of units and net income used to calculate basic and diluted earnings per common partnership unit (in thousands, except unit and per unit amounts; results may not add due to rounding): Year Ended December 31, 2021 2020 2019 Basic Diluted Basic Diluted Basic Diluted Numerator Net income $ 12,366 $ 12,366 $ 307,326 $ 307,326 $ 34,529 $ 34,529 Net (income) loss attributable to noncontrolling interests 3 3 (20) (20) (69) (69) Nonforfeitable dividends allocated to unvested restricted unitholders (421) (421) (410) (410) (396) (396) Net income attributable to common unitholders $ 11,948 $ 11,948 $ 306,896 $ 306,896 $ 34,064 $ 34,064 Denominator Weighted-average units outstanding 171,770,843 171,770,843 172,907,713 172,907,713 177,114,932 177,114,932 Contingent securities/Share based compensation — 1,395,055 — 390,997 — 553,872 Total weighted-average units outstanding 171,770,843 173,165,898 172,907,713 173,298,710 177,114,932 177,668,804 Earnings per Common Partnership Unit: Net income attributable to common unitholders $ 0.07 $ 0.07 $ 1.77 $ 1.77 $ 0.19 $ 0.19

PARTNERS' EQUITY OF THE PAREN_2

PARTNERS' EQUITY OF THE PARENT COMPANY (Tables)	12 Months Ended
	Dec. 31, 2021
Equity [Abstract]
Earnings Per Share (EPS), Basic and Diluted	The following table details the number of shares and net income used to calculate basic and diluted earnings per share (in thousands, except share and per share amounts; results may not add due to rounding): Year Ended December 31, 2021 2020 2019 Basic Diluted Basic Diluted Basic Diluted Numerator Net income $ 12,366 $ 12,366 $ 307,326 $ 307,326 $ 34,529 $ 34,529 Net income attributable to noncontrolling interests (77) (77) (1,799) (1,799) (262) (262) Nonforfeitable dividends allocated to unvested restricted shareholders (421) (421) (410) (410) (396) (396) Net income attributable to common shareholders $ 11,868 $ 11,868 $ 305,117 $ 305,117 $ 33,871 $ 33,871 Denominator Weighted-average shares outstanding 170,878,185 170,878,185 171,926,079 171,926,079 176,132,941 176,132,941 Contingent securities/Share based compensation — 1,395,055 — 390,997 — 553,872 Weighted-average shares outstanding 170,878,185 172,273,240 171,926,079 172,317,076 176,132,941 176,686,813 Earnings per Common Share: Net income attributable to common shareholders $ 0.07 $ 0.07 $ 1.77 $ 1.77 $ 0.19 $ 0.19 The following table details the number of units and net income used to calculate basic and diluted earnings per common partnership unit (in thousands, except unit and per unit amounts; results may not add due to rounding): Year Ended December 31, 2021 2020 2019 Basic Diluted Basic Diluted Basic Diluted Numerator Net income $ 12,366 $ 12,366 $ 307,326 $ 307,326 $ 34,529 $ 34,529 Net (income) loss attributable to noncontrolling interests 3 3 (20) (20) (69) (69) Nonforfeitable dividends allocated to unvested restricted unitholders (421) (421) (410) (410) (396) (396) Net income attributable to common unitholders $ 11,948 $ 11,948 $ 306,896 $ 306,896 $ 34,064 $ 34,064 Denominator Weighted-average units outstanding 171,770,843 171,770,843 172,907,713 172,907,713 177,114,932 177,114,932 Contingent securities/Share based compensation — 1,395,055 — 390,997 — 553,872 Total weighted-average units outstanding 171,770,843 173,165,898 172,907,713 173,298,710 177,114,932 177,668,804 Earnings per Common Partnership Unit: Net income attributable to common unitholders $ 0.07 $ 0.07 $ 1.77 $ 1.77 $ 0.19 $ 0.19

SHARE BASED COMPENSATION, 401_2

SHARE BASED COMPENSATION, 401(K) PLAN AND DEFERRED COMPENSATION (Tables)	12 Months Ended
	Dec. 31, 2021
Share-based Payment Arrangement [Abstract]
Company's Restricted Share Activity	The following table summarizes the Company’s Restricted Share Rights activity during the year-ended December 31, 2021: Shares Weighted Average Grant Date Fair Value Non-vested at January 1, 2021 488,735 $ 15.19 Granted 343,179 $ 12.72 Vested (339,579) $ 15.12 Forfeited (17,357) $ 13.55 Non-vested at December 31, 2021 474,978 $ 13.51
Schedule of Restricted Performance Share Units Plan	The table below presents certain information as to unvested RPSU awards. RPSU Grant Date 2/21/2019 3/5/2020 3/5/2021 Total (Amounts below in shares, unless otherwise noted) Non-vested at January 1, 2021 206,069 319,600 — 525,669 Granted — — 380,957 380,957 Units Cancelled (3,837) (5,545) (6,796) (16,178) Non-vested at December 31, 2021 202,232 314,055 374,161 890,448 Measurement Period Commencement Date 1/1/2019 1/1/2020 1/1/2021 Measurement Period End Date 12/31/2021 12/31/2022 12/31/2023 Granted 213,728 319,600 380,957 Fair Value of Units on Grant Date (in thousands) $ 4,627 $ 5,389 $ 6,389

DISTRIBUTIONS (Tables)

DISTRIBUTIONS (Tables)	12 Months Ended
	Dec. 31, 2021
Distributions [Abstract]
Schedule of Dividends Payable	The following table provides the tax characteristics of the 2021, 2020 and 2019 distributions paid: Years ended December 31, 2021 2020 2019 (in thousands, except per share amounts) Common Share Distributions: Ordinary income $ 0.64 $ 0.41 $ 0.62 Capital gain 0.01 0.35 — Non-taxable distributions 0.11 — 0.14 Distributions per share $ 0.76 $ 0.76 $ 0.76 Percentage classified as ordinary income 83.90 % 53.90 % 81.00 % Percentage classified as capital gain 1.20 % 46.10 % — % Percentage classified as non-taxable distribution 14.90 % — % 19.00 %

ACCUMULATED OTHER COMPREHENSI_2

ACCUMULATED OTHER COMPREHENSIVE INCOME (LOSS) (Tables)	12 Months Ended
	Dec. 31, 2021
Stockholders' Equity Note [Abstract]
Schedule of Accumulated Other Comprehensive Income (Loss)	The following table details the components of accumulated other comprehensive income (loss) of the Parent Company and the Operating Partnership as of and for the three years ended December 31, 2021 (in thousands): Parent Company Cash Flow Hedges Balance at January 1, 2019 $ 5,029 Change in fair market value during year (8,210) Allocation of unrealized (gains)/losses on derivative financial instruments to noncontrolling interests 41 Amortization of interest rate contracts reclassified from comprehensive income to interest expense 770 Balance at December 31, 2019 $ (2,370) Change in fair market value during year (5,972) Allocation of unrealized (gains)/losses on derivative financial instruments to noncontrolling interests 29 Amortization of interest rate contracts reclassified from comprehensive income to interest expense 752 Balance at December 31, 2020 $ (7,561) Change in fair market value during year 4,817 Allocation of unrealized (gains)/losses on derivative financial instruments to noncontrolling interests (28) Amortization of interest rate contracts reclassified from comprehensive income to interest expense 752 Balance at December 31, 2021 $ (2,020) Operating Partnership Cash Flow Hedges Balance at January 1, 2019 $ 4,725 Change in fair market value during year (8,210) Amortization of interest rate contracts reclassified from comprehensive income to interest expense 770 Balance at December 31, 2019 $ (2,715) Change in fair market value during year (5,972) Amortization of interest rate contracts reclassified from comprehensive income to interest expense 752 Balance at December 31, 2020 $ (7,935) Change in fair market value during year 4,817 Amortization of interest rate contracts reclassified from comprehensive income to interest expense 752 Balance at December 31, 2021 $ (2,366)

SEGMENT INFORMATION (Tables)

SEGMENT INFORMATION (Tables)	12 Months Ended
	Dec. 31, 2021
Segment Reporting [Abstract]
Real Estate Investments, Net Operating Income and Unconsolidated Real Estate Ventures of Reportable Segments	The following tables provide selected asset information and results of operations of the Company’s reportable segments (in thousands): Real estate investments, at cost: December 31, 2021 December 31, 2020 Philadelphia CBD $ 1,460,510 $ 1,433,927 Pennsylvania Suburbs 866,223 871,530 Austin, Texas 778,145 728,741 Metropolitan Washington, D.C. 280,921 352,794 Other 86,803 87,117 Operating Properties $ 3,472,602 $ 3,474,109 Corporate Right of use asset - operating leases, net $ 20,313 $ 20,977 Construction-in-progress $ 277,237 $ 210,311 Land held for development $ 114,604 $ 117,984 Prepaid leasehold interests in land held for development, net $ 27,762 $ 39,185 . Net operating income: Year Ended December 31, 2021 2020 2019 Total revenue Operating expenses (a) Net operating income Total revenue Operating expenses (a) Net operating income (loss) Total revenue Operating expenses (a) Net operating income (loss) Philadelphia CBD $ 207,858 $ (73,695) $ 134,163 $ 232,028 $ (82,505) $ 149,523 $ 263,769 $ (100,219) $ 163,550 Pennsylvania Suburbs 124,566 (40,011) 84,555 141,613 (46,281) 95,332 141,084 (47,418) 93,666 Austin, Texas 101,680 (39,374) 62,306 102,982 (39,759) 63,223 104,157 (38,285) 65,872 Metropolitan Washington, D.C. 19,865 (15,386) 4,479 40,223 (20,791) 19,432 51,498 (23,455) 28,043 Other 14,015 (9,840) 4,175 13,469 (9,815) 3,654 14,558 (9,328) 5,230 Corporate 18,835 (10,005) 8,830 4,537 (6,305) (1,768) 5,351 (7,141) (1,790) Operating properties $ 486,819 $ (188,311) $ 298,508 $ 534,852 $ (205,456) $ 329,396 $ 580,417 $ (225,846) $ 354,571 (a) Includes property operating expense, real estate taxes and third party management expense. Unconsolidated real estate ventures: Investment in real estate ventures, at equity Equity in income (loss) of real estate venture As of Year ended December 31, December 31, 2021 December 31, 2020 2021 2020 2019 Philadelphia CBD $ 317,959 $ 268,562 $ (15,191) $ (9,090) $ 328 Metropolitan Washington, D.C. 85,867 99,769 (3,755) (3,019) (4,234) Mid-Atlantic Office JV 31,680 32,996 932 96 — MAP Venture (24,396) (11,516) (8,683) (6,571) (6,102) Other — — — — 86 Total $ 411,110 $ 389,811 $ (26,697) $ (18,584) $ (9,922)
Reconciliation of Consolidated Net Income (Loss) to Consolidated NOI	The following is a reconciliation of consolidated net income (loss), as defined by GAAP, to consolidated NOI, (in thousands): Year Ended December 31, 2021 2020 2019 Net income $ 12,366 $ 307,326 $ 34,529 Plus: Interest expense 62,617 73,911 81,512 Interest expense - amortization of deferred financing costs 2,836 2,904 2,768 Depreciation and amortization 178,105 188,283 210,005 General and administrative expenses 30,153 30,288 32,156 Equity in loss of unconsolidated real estate ventures 26,697 18,584 9,922 Less: Interest and investment income 8,295 1,939 2,318 Income tax (provision) benefit (47) 224 (12) Net gain on disposition of real estate 142 289,461 356 Net gain on sale of undepreciated real estate 2,903 201 2,020 Net gain on real estate venture transactions 2,973 75 11,639 Consolidated net operating income $ 298,508 $ 329,396 $ 354,571

ORGANIZATION OF THE PARENT CO_3

ORGANIZATION OF THE PARENT COMPANY AND THE OPERATING PARTNERSHIP - Narrative (Details)	12 Months Ended
	Dec. 31, 2021ft²amanagementCompanypropertyparcel
Organization of The Parent Company and The Operating Partnership [Line Items]
Number of real estate properties | property	81
Area of real estate property	13,678,136
Number of management companies | managementCompany	7
Wholly Owned Properties
Organization of The Parent Company and The Operating Partnership [Line Items]
Area of real estate property	13,700,000
Parent Company
Organization of The Parent Company and The Operating Partnership [Line Items]
Area of undeveloped parcels of land | a	176.1
Area of undeveloped land held for sale | a	10
Area of additional undeveloped parcels of land with option to purchase | a	55.5
Total potential development capacity	13,400,000
Parent Company | Land Parcel One
Organization of The Parent Company and The Operating Partnership [Line Items]
Lease agreement term	99 years
Parent Company | Land Parcel Two
Organization of The Parent Company and The Operating Partnership [Line Items]
Lease agreement term	99 years
Parent Company | Held for Sale Properties Included in Continuing Operations
Organization of The Parent Company and The Operating Partnership [Line Items]
Total potential development capacity	100,000
Wholly-owned Management Company Subsidiaries
Organization of The Parent Company and The Operating Partnership [Line Items]
Area of real estate property	23,100,000
Wholly-owned Management Company Subsidiaries | Wholly Owned Properties
Organization of The Parent Company and The Operating Partnership [Line Items]
Area of real estate property	13,700,000
Wholly-owned Management Company Subsidiaries | Partially Owned Properties
Organization of The Parent Company and The Operating Partnership [Line Items]
Area of real estate property	9,400,000
Leashold Interest Land
Organization of The Parent Company and The Operating Partnership [Line Items]
Lease agreement term	99 years
Leashold Interest Land | Parent Company
Organization of The Parent Company and The Operating Partnership [Line Items]
Number of real estate properties | parcel	1
Undeveloped parcels of land held | a	0.8
Brandywine Operating Partnership LP
Organization of The Parent Company and The Operating Partnership [Line Items]
Ownership in the operating partnership	99.50%
BRSCO | BRANDYWINE OPERATING PARTNERSHIP, L.P. | Brandywine Operating Partnership LP
Organization of The Parent Company and The Operating Partnership [Line Items]
Ownership in the operating partnership	100.00%
BMH | BRANDYWINE OPERATING PARTNERSHIP, L.P. | Brandywine Operating Partnership LP
Organization of The Parent Company and The Operating Partnership [Line Items]
Ownership in the operating partnership	100.00%
BPI | BRANDYWINE OPERATING PARTNERSHIP, L.P. | Brandywine Operating Partnership LP
Organization of The Parent Company and The Operating Partnership [Line Items]
Ownership in the operating partnership	100.00%
BBL | BRANDYWINE OPERATING PARTNERSHIP, L.P. | Brandywine Operating Partnership LP
Organization of The Parent Company and The Operating Partnership [Line Items]
Ownership in the operating partnership	100.00%
BPM | BRANDYWINE OPERATING PARTNERSHIP, L.P. | Brandywine Operating Partnership LP
Organization of The Parent Company and The Operating Partnership [Line Items]
Ownership in the operating partnership	100.00%
BBS | BRANDYWINE OPERATING PARTNERSHIP, L.P. | Brandywine Operating Partnership LP
Organization of The Parent Company and The Operating Partnership [Line Items]
Ownership in the operating partnership	100.00%
BGCS | BRANDYWINE OPERATING PARTNERSHIP, L.P. | Brandywine Operating Partnership LP
Organization of The Parent Company and The Operating Partnership [Line Items]
Ownership in the operating partnership	100.00%
Unconsolidated Real Estate Ventures | Unconsolidated Properties
Organization of The Parent Company and The Operating Partnership [Line Items]
Number of real estate properties | property	9

ORGANIZATION OF THE PARENT CO_4

ORGANIZATION OF THE PARENT COMPANY AND THE OPERATING PARTNERSHIP - Summary of Core Portfolio of Operating Properties and Excludes Development, Redevelopment and Held for Sale (Details)	Dec. 31, 2021ft²property
Real Estate Properties [Line Items]
Number of Properties | property	81
Rentable Square Feet | ft²	13,678,136
Core Properties
Real Estate Properties [Line Items]
Number of Properties | property	77
Rentable Square Feet | ft²	13,039,634
Office properties
Real Estate Properties [Line Items]
Number of Properties | property	72
Rentable Square Feet | ft²	12,097,300
Mixed-use properties
Real Estate Properties [Line Items]
Number of Properties | property	5
Rentable Square Feet | ft²	942,334
Development property
Real Estate Properties [Line Items]
Number of Properties | property	1
Rentable Square Feet | ft²	205,803
Redevelopment properties
Real Estate Properties [Line Items]
Number of Properties | property	3
Rentable Square Feet | ft²	432,699

SUMMARY OF SIGNIFICANT ACCOUN_4

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Change in Depreciable Lives of Real Estate Investments (Details) - Service Life $ in Millions	12 Months Ended
	Dec. 31, 2021USD ($)property	Dec. 31, 2020
Real Estate Properties [Line Items]
Number of properties that changed estimated useful lives | property	7
Property, plant, and equipment, estimated useful life	12 years	35 years
Depreciation | $	$ 9.8

SUMMARY OF SIGNIFICANT ACCOUN_5

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Principles of Consolidation (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Variable Interest Entity [Line Items]
Assets	$ 3,846,196	$ 3,900,106
Liabilities	2,144,977	2,095,458
Variable Interest Entity
Variable Interest Entity [Line Items]
Assets	46,500	49,200
Liabilities	$ 21,000	$ 21,600

SUMMARY OF SIGNIFICANT ACCOUN_6

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Purchase Price Allocation and Depreciation and Amortization (Details)	12 Months Ended
	Dec. 31, 2021
Minimum
Construction in Progress [Line Items]
Expected lease-up periods	4 months
Minimum | Buildings and Improvements
Construction in Progress [Line Items]
Buildings and improvements useful life	5 years
Minimum | Tenant Improvements
Construction in Progress [Line Items]
Buildings and improvements useful life	1 year
Maximum
Construction in Progress [Line Items]
Expected lease-up periods	12 months
Maximum | Buildings and Improvements
Construction in Progress [Line Items]
Buildings and improvements useful life	55 years
Maximum | Tenant Improvements
Construction in Progress [Line Items]
Buildings and improvements useful life	16 years

SUMMARY OF SIGNIFICANT ACCOUN_7

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Impairment of Real Estate Assets (Details)	12 Months Ended
	Dec. 31, 2021
Accounting Policies [Abstract]
Disposition of assets, holding period	10 years

SUMMARY OF SIGNIFICANT ACCOUN_8

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Deferred Costs (Details)	Dec. 31, 2021
Minimum
Lessor, Lease, Description [Line Items]
Deferred cost, amortization period	1 year
Maximum
Lessor, Lease, Description [Line Items]
Deferred cost, amortization period	16 years

SUMMARY OF SIGNIFICANT ACCOUN_9

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Disaggregation of Revenue (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Disaggregation of Revenue [Line Items]
Total revenue	$ 486,819	$ 534,852	$ 580,417
Rents
Disaggregation of Revenue [Line Items]
Total revenue	451,519	513,504	554,665
Total lease revenue
Disaggregation of Revenue [Line Items]
Total revenue	433,766	497,264	525,748
Fixed rent
Disaggregation of Revenue [Line Items]
Total revenue	343,924	393,178	411,524
Variable rent
Disaggregation of Revenue [Line Items]
Total revenue	89,842	104,086	114,224
Amortization of deferred market rents
Disaggregation of Revenue [Line Items]
Total revenue	5,377	4,868	8,857
Daily parking & hotel flexible stay
Disaggregation of Revenue [Line Items]
Total revenue	12,376	11,372	20,060
Third party management fees, labor reimbursement and leasing
Disaggregation of Revenue [Line Items]
Total revenue	26,444	18,580	19,626
Other
Disaggregation of Revenue [Line Items]
Total revenue	8,856	2,768	6,126
Philadelphia CBD
Disaggregation of Revenue [Line Items]
Total revenue	207,858	232,028	263,769
Philadelphia CBD | Rents
Disaggregation of Revenue [Line Items]
Total revenue	204,848	229,619	259,471
Philadelphia CBD | Total lease revenue
Disaggregation of Revenue [Line Items]
Total revenue	191,026	217,696	237,061
Philadelphia CBD | Fixed rent
Disaggregation of Revenue [Line Items]
Total revenue	149,441	166,286	178,481
Philadelphia CBD | Variable rent
Disaggregation of Revenue [Line Items]
Total revenue	41,585	51,410	58,580
Philadelphia CBD | Amortization of deferred market rents
Disaggregation of Revenue [Line Items]
Total revenue	2,064	1,146	3,745
Philadelphia CBD | Daily parking & hotel flexible stay
Disaggregation of Revenue [Line Items]
Total revenue	11,758	10,777	18,665
Philadelphia CBD | Third party management fees, labor reimbursement and leasing
Disaggregation of Revenue [Line Items]
Total revenue	893	927	876
Philadelphia CBD | Other
Disaggregation of Revenue [Line Items]
Total revenue	2,117	1,482	3,422
Pennsylvania Suburbs
Disaggregation of Revenue [Line Items]
Total revenue	124,566	141,613	141,084
Pennsylvania Suburbs | Rents
Disaggregation of Revenue [Line Items]
Total revenue	124,256	141,162	140,413
Pennsylvania Suburbs | Total lease revenue
Disaggregation of Revenue [Line Items]
Total revenue	124,106	140,995	140,251
Pennsylvania Suburbs | Fixed rent
Disaggregation of Revenue [Line Items]
Total revenue	113,748	128,044	125,969
Pennsylvania Suburbs | Variable rent
Disaggregation of Revenue [Line Items]
Total revenue	10,358	12,951	14,282
Pennsylvania Suburbs | Amortization of deferred market rents
Disaggregation of Revenue [Line Items]
Total revenue	(9)	(12)	(12)
Pennsylvania Suburbs | Daily parking & hotel flexible stay
Disaggregation of Revenue [Line Items]
Total revenue	159	179	174
Pennsylvania Suburbs | Third party management fees, labor reimbursement and leasing
Disaggregation of Revenue [Line Items]
Total revenue	34	39	43
Pennsylvania Suburbs | Other
Disaggregation of Revenue [Line Items]
Total revenue	276	412	628
Austin, Texas
Disaggregation of Revenue [Line Items]
Total revenue	101,680	102,982	104,157
Austin, Texas | Rents
Disaggregation of Revenue [Line Items]
Total revenue	100,826	102,069	101,783
Austin, Texas | Total lease revenue
Disaggregation of Revenue [Line Items]
Total revenue	97,395	98,489	96,980
Austin, Texas | Fixed rent
Disaggregation of Revenue [Line Items]
Total revenue	62,545	63,366	62,232
Austin, Texas | Variable rent
Disaggregation of Revenue [Line Items]
Total revenue	34,850	35,123	34,748
Austin, Texas | Amortization of deferred market rents
Disaggregation of Revenue [Line Items]
Total revenue	3,322	3,531	4,638
Austin, Texas | Daily parking & hotel flexible stay
Disaggregation of Revenue [Line Items]
Total revenue	109	49	165
Austin, Texas | Third party management fees, labor reimbursement and leasing
Disaggregation of Revenue [Line Items]
Total revenue	452	689	1,956
Austin, Texas | Other
Disaggregation of Revenue [Line Items]
Total revenue	402	224	418
Metropolitan Washington, D.C.
Disaggregation of Revenue [Line Items]
Total revenue	19,865	40,223	51,498
Metropolitan Washington, D.C. | Rents
Disaggregation of Revenue [Line Items]
Total revenue	13,173	33,509	44,273
Metropolitan Washington, D.C. | Total lease revenue
Disaggregation of Revenue [Line Items]
Total revenue	13,056	33,374	43,449
Metropolitan Washington, D.C. | Fixed rent
Disaggregation of Revenue [Line Items]
Total revenue	12,410	29,830	39,420
Metropolitan Washington, D.C. | Variable rent
Disaggregation of Revenue [Line Items]
Total revenue	646	3,544	4,029
Metropolitan Washington, D.C. | Amortization of deferred market rents
Disaggregation of Revenue [Line Items]
Total revenue	0	0	0
Metropolitan Washington, D.C. | Daily parking & hotel flexible stay
Disaggregation of Revenue [Line Items]
Total revenue	117	135	824
Metropolitan Washington, D.C. | Third party management fees, labor reimbursement and leasing
Disaggregation of Revenue [Line Items]
Total revenue	6,548	6,541	6,922
Metropolitan Washington, D.C. | Other
Disaggregation of Revenue [Line Items]
Total revenue	144	173	303
Other
Disaggregation of Revenue [Line Items]
Total revenue	14,015	13,469	14,558
Other | Rents
Disaggregation of Revenue [Line Items]
Total revenue	10,913	10,900	11,632
Other | Total lease revenue
Disaggregation of Revenue [Line Items]
Total revenue	10,680	10,465	10,914
Other | Fixed rent
Disaggregation of Revenue [Line Items]
Total revenue	8,020	8,064	7,834
Other | Variable rent
Disaggregation of Revenue [Line Items]
Total revenue	2,660	2,401	3,080
Other | Amortization of deferred market rents
Disaggregation of Revenue [Line Items]
Total revenue	0	203	486
Other | Daily parking & hotel flexible stay
Disaggregation of Revenue [Line Items]
Total revenue	233	232	232
Other | Third party management fees, labor reimbursement and leasing
Disaggregation of Revenue [Line Items]
Total revenue	3,077	2,560	2,915
Other | Other
Disaggregation of Revenue [Line Items]
Total revenue	25	9	11
Corporate
Disaggregation of Revenue [Line Items]
Total revenue	18,835	4,537	5,351
Corporate | Rents
Disaggregation of Revenue [Line Items]
Total revenue	(2,497)	(3,755)	(2,907)
Corporate | Total lease revenue
Disaggregation of Revenue [Line Items]
Total revenue	(2,497)	(3,755)	(2,907)
Corporate | Fixed rent
Disaggregation of Revenue [Line Items]
Total revenue	(2,240)	(2,412)	(2,412)
Corporate | Variable rent
Disaggregation of Revenue [Line Items]
Total revenue	(257)	(1,343)	(495)
Corporate | Amortization of deferred market rents
Disaggregation of Revenue [Line Items]
Total revenue	0	0	0
Corporate | Daily parking & hotel flexible stay
Disaggregation of Revenue [Line Items]
Total revenue	0	0	0
Corporate | Third party management fees, labor reimbursement and leasing
Disaggregation of Revenue [Line Items]
Total revenue	15,440	7,824	6,914
Corporate | Other
Disaggregation of Revenue [Line Items]
Total revenue	$ 5,892	$ 468	$ 1,344

SUMMARY OF SIGNIFICANT ACCOU_10

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Income Taxes (Details) - USD ($) $ in Billions	Dec. 31, 2021	Dec. 31, 2020
Income Tax Contingency [Line Items]
Tax basis of assets, cost for income tax purposes	$ 3.1	$ 2.9
BRANDYWINE OPERATING PARTNERSHIP, L.P.
Income Tax Contingency [Line Items]
Tax basis of assets, cost for income tax purposes	$ 3.1	$ 2.9

REAL ESTATE INVESTMENTS - Gross

REAL ESTATE INVESTMENTS - Gross Carrying Value of Operating Properties (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Real Estate [Abstract]
Land	$ 410,144	$ 407,514
Building and improvements	2,653,492	2,665,232
Tenant improvements	408,966	401,363
Total	$ 3,472,602	$ 3,474,109

REAL ESTATE INVESTMENTS - Capit

REAL ESTATE INVESTMENTS - Capitalized Construction Costs (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Property, Plant and Equipment [Line Items]
Internal direct construction costs capitalized related to development of properties and land holdings	$ 7,902	$ 8,366	$ 7,431
Capitalized interest	7,000	4,600	3,200
Development
Property, Plant and Equipment [Line Items]
Internal direct construction costs capitalized related to development of properties and land holdings	4,815	4,802	3,047
Redevelopment
Property, Plant and Equipment [Line Items]
Internal direct construction costs capitalized related to development of properties and land holdings	1,170	543	775
Tenant Improvements
Property, Plant and Equipment [Line Items]
Internal direct construction costs capitalized related to development of properties and land holdings	$ 1,917	$ 3,021	$ 3,609

REAL ESTATE INVESTMENTS - Summa

REAL ESTATE INVESTMENTS - Summary of Acquired Properties (Details) $ in Thousands	Nov. 30, 2020USD ($)ft²	Nov. 05, 2020USD ($)ft²	Feb. 27, 2020USD ($)a	Dec. 31, 2021USD ($)	Dec. 31, 2020USD ($)	Dec. 31, 2019USD ($)
Business Acquisition [Line Items]
Purchase Price				$ 0	$ 41,950	$ 0
Land | 145 King of Prussia Road
Business Acquisition [Line Items]
Land area | a			7.75
Purchase Price			$ 11,250
Office | 1505-11 Race Street
Business Acquisition [Line Items]
Rentable Square Feet | ft²		119,763
Purchase Price		$ 9,700
Office | 250 King of Prussia Road
Business Acquisition [Line Items]
Rentable Square Feet | ft²	169,843
Purchase Price	$ 20,250

REAL ESTATE INVESTMENTS - Asset

REAL ESTATE INVESTMENTS - Asset Acquisition (Details) - 1505-11 Race Street $ in Thousands	Nov. 05, 2020USD ($)
Schedule of Investments [Line Items]
Building, land and improvements	$ 9,723
Intangible assets acquired	2,422
Below market lease liabilities assumed	(2,193)
Total unencumbered acquisition value	$ 9,952
Below Market Lease
Schedule of Investments [Line Items]
Weighted average amortization period	1 year 6 months
Intangible Assets Acquired
Schedule of Investments [Line Items]
Weighted average amortization period	1 year 6 months

REAL ESTATE INVESTMENTS - Sum_2

REAL ESTATE INVESTMENTS - Summary of Office Properties Sold (Details) $ in Thousands	Sep. 08, 2021USD ($)ft²	Jul. 06, 2021USD ($)ft²	Dec. 21, 2020USD ($)ft²property	Jul. 21, 2020USD ($)ft²property	Jun. 15, 2020USD ($)a	Mar. 19, 2020USD ($)ft²	Sep. 11, 2019USD ($)ft²	Mar. 15, 2019USD ($)a	Dec. 31, 2021USD ($)	Dec. 31, 2020USD ($)	Dec. 31, 2019USD ($)
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Gain (Loss) on Sale									$ 142	$ 289,461	$ 356
Sale of ownership interest percentage			60.00%
Mid-Atlantic Office Portfolio
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Variable consideration			$ 4,100
Mid-Atlantic Office Portfolio | Minimum
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Variable consideration holdback term			6 months
Mid-Atlantic Office Portfolio | Maximum
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Variable consideration holdback term			9 months
Commerce Square
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Sales Price				$ 115,000
Sale of ownership interest percentage				30.00%
Value of assets disposed of				$ 600,000
Deconsolidation gain				$ 271,900
Land
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Gain (Loss) on Sale											$ 1,000
Land | 1100 Lenox Drive
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Land area | ft²	5
Sales Price	$ 2,575
Gain (Loss) on Sale	$ 68
Land | 2100-2200 Lenox Drive
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Land area | ft²		35.2
Sales Price		$ 8,900
Gain (Loss) on Sale		$ 842
Land | Keith Valley
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Land area | a					14
Sales Price					$ 4,000
Gain (Loss) on Sale					$ 201
Land | 9 Presidential Boulevard
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Land area | a								2.7
Sales Price								$ 5,325
Gain (Loss) on Sale								$ 751
Office | Mid-Atlantic Office Portfolio
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Rentable Square Feet | ft²			1,128,645
Sales Price			$ 192,943
Gain (Loss) on Sale			$ 15,164
Number of properties sold | property			12
Office | Mid-Atlantic Office Portfolio | Pennsylvania
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of properties sold | property			9
Office | Mid-Atlantic Office Portfolio | Maryland
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of properties sold | property			3
Office | Commerce Square
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Rentable Square Feet | ft²			1,896,142	1,896,142
Sales Price				$ 115,000
Gain (Loss) on Sale				$ 271,905
Number of properties sold | property				2
Office | 52 East Swedesford Road
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Rentable Square Feet | ft²						131,077
Sales Price						$ 18,000
Gain (Loss) on Sale						$ 2,336
Office | 1900 Gallows Rd
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Rentable Square Feet | ft²							210,632
Sales Price							$ 36,400
Gain (Loss) on Sale							$ (367)

REAL ESTATE INVESTMENTS - Dispo

REAL ESTATE INVESTMENTS - Dispositions Narrative (Details) $ in Thousands	Feb. 02, 2021USD ($)	Dec. 31, 2021USD ($)	Dec. 31, 2020USD ($)	Dec. 31, 2019USD ($)	Jul. 23, 2021USD ($)	Feb. 02, 2021a	Feb. 02, 2021ft²	Nov. 05, 2020USD ($)
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Net gain on sale of undepreciated real estate		$ 2,903	$ 201	$ 2,020
Net gain on disposition of real estate		$ 142	$ 289,461	356
Prior Period Disposals
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Net gain on disposition of real estate				700
Land
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Net gain on disposition of real estate				$ 1,000
3025 JFK Venture
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Lease agreement term	99 years
Land area						1	1
Investment in real estate venture	$ 34,800				$ 34,800
Net gain on sale of undepreciated real estate	$ 2,000
1505-11 Race Street
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Transaction costs capitalized								$ 300

REAL ESTATE INVESTMENTS - One U

REAL ESTATE INVESTMENTS - One Uptown Venture (Narrative) (Details) $ in Millions	Dec. 31, 2021ft²	Dec. 01, 2021USD ($)ft²propertyapartment
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Area of real estate property | ft²	13,678,136
One Uptown Venture
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Investment in real estate venture | $		$ 328.4
Number of apartment residences | apartment		341
Joint venture, funding committed by other party | $		$ 57.5
Construction loan, percent		65.00%
One Uptown Venture | Canyon Partners Real Estate
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of joint ventures | property		2
One Uptown Venture | Construction Loans
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Long-term debt, gross | $		$ 213.4
One Uptown Venture | Preferred Stock
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Ownership percentage		50.00%
One Uptown Venture | Common Stock
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Ownership percentage		50.00%
One Uptown Venture | Class A Workspace
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Area of real estate property | ft²		348,000
One Uptown Venture | Street Level Retail
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Area of real estate property | ft²		15,000

REAL ESTATE INVESTMENTS - Held

REAL ESTATE INVESTMENTS - Held for Use Impairment and Sale (Narrative) (Details)	12 Months Ended
	Dec. 31, 2021USD ($)aparcel	Dec. 31, 2020USD ($)	Dec. 31, 2019USD ($)	Jan. 20, 2022USD ($)
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Impairment of properties held for use	$ 0	$ 0	$ 0
Assets held for sale, net	562,000	$ 7,349,000
Held for Sale Properties Included in Continuing Operations | Other Land
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Assets held for sale, net	$ 600,000
Held for Sale Properties Included in Continuing Operations | Other Land | Subsequent Event
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Aggregate sales price				$ 1,600,000
Held for Sale Properties Included in Continuing Operations | Other Land | Other
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of land parcels | parcel	2
Land area | a	10

INVESTMENT IN UNCONSOLIDATED _3

INVESTMENT IN UNCONSOLIDATED REAL ESTATE VENTURES - Narrative (Details) $ in Thousands, ft² in Millions	12 Months Ended
	Dec. 31, 2021USD ($)ft²apropertyapartment	Dec. 31, 2020USD ($)	Dec. 31, 2019USD ($)
Schedule of Equity Method Investments [Line Items]
Number of real estate properties	81
Investment balance | $	$ 411,110	$ 389,811
Accounts receivable | $	11,875	13,536
Real Estate Venture
Schedule of Equity Method Investments [Line Items]
Accounts receivable | $	2,500	1,200
Management Fees | Real Estate Venture
Schedule of Equity Method Investments [Line Items]
Service and other revenue | $	8,100	4,700	$ 4,300
Leasing Commission Income | Real Estate Venture
Schedule of Equity Method Investments [Line Items]
Service and other revenue | $	3,800	$ 1,100	$ 1,700
Unconsolidated Real Estate Ventures
Schedule of Equity Method Investments [Line Items]
Investment balance | $	$ 411,100
Unconsolidated Real Estate Ventures | Minimum
Schedule of Equity Method Investments [Line Items]
Ownership percentage	15.00%
Unconsolidated Real Estate Ventures | Maximum
Schedule of Equity Method Investments [Line Items]
Ownership percentage	70.00%
Unconsolidated Real Estate Ventures | Office Properties
Schedule of Equity Method Investments [Line Items]
Number of unconsolidated investments in Real Estate Ventures	4
Rentable square feet | ft²	8.2
Unconsolidated Real Estate Ventures | Other Liabilities
Schedule of Equity Method Investments [Line Items]
Investment balance | $	$ (24,400)
Unconsolidated Real Estate Ventures | Unconsolidated Properties
Schedule of Equity Method Investments [Line Items]
Number of real estate properties	9
Number of real estate properties with negative investment balances	1
Unconsolidated Real Estate Ventures | Land Held For Development
Schedule of Equity Method Investments [Line Items]
Number of unconsolidated investments in Real Estate Ventures	2
Land area | a	1.4
Unconsolidated Real Estate Ventures | Land Under Active Development
Schedule of Equity Method Investments [Line Items]
Number of unconsolidated investments in Real Estate Ventures	1
Land area | a	1
Unconsolidated Real Estate Ventures | Mixed Use Tower
Schedule of Equity Method Investments [Line Items]
Number of unconsolidated investments in Real Estate Ventures	1
Rentable square feet | ft²	0.2
Number of property units | apartment	250
Unconsolidated Real Estate Ventures | Residential Tower
Schedule of Equity Method Investments [Line Items]
Number of unconsolidated investments in Real Estate Ventures	1
Number of property units | apartment	321

INVESTMENT IN UNCONSOLIDATED _4

INVESTMENT IN UNCONSOLIDATED REAL ESTATE VENTURES - Investment in Real Estate Ventures and Share of Real Estate Ventures' Income (Loss) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019	Dec. 21, 2020	Jul. 31, 2013
Schedule of Equity Method Investments [Line Items]
Carrying Amount	$ 411,110	$ 389,811
Company's Share of unconsolidated real estate venture Income (Loss)	(26,697)	(18,584)	$ (9,922)
Unconsolidated Real Estate Venture Debt at 100%, gross	$ 961,509	963,018
Commerce Square Venture
Schedule of Equity Method Investments [Line Items]
Ownership Percentage	70.00%
Carrying Amount	$ 247,798	253,128
Company's Share of unconsolidated real estate venture Income (Loss)	(15,501)	(9,150)
Unconsolidated Real Estate Venture Debt at 100%, gross	$ 213,069	219,168
Mid-Atlantic Office Venture
Schedule of Equity Method Investments [Line Items]
Ownership Percentage	40.00%			40.00%
Carrying Amount	$ 31,680	32,996
Company's Share of unconsolidated real estate venture Income (Loss)	932	96
Unconsolidated Real Estate Venture Debt at 100%, gross	$ 123,015	120,831
Brandywine - AI Venture LLC
Schedule of Equity Method Investments [Line Items]
Ownership Percentage	50.00%
Carrying Amount	$ 0	10,302
Company's Share of unconsolidated real estate venture Income (Loss)	(721)	185	(2,800)
Unconsolidated Real Estate Venture Debt at 100%, gross	$ 0	0
Herndon Innovation Center Metro Portfolio Venture, LLC
Schedule of Equity Method Investments [Line Items]
Ownership Percentage	15.00%
Carrying Amount	$ 15,844	16,019
Company's Share of unconsolidated real estate venture Income (Loss)	(174)	(358)	(498)
Unconsolidated Real Estate Venture Debt at 100%, gross	$ 207,302	207,302
MAP Venture
Schedule of Equity Method Investments [Line Items]
Ownership Percentage	50.00%
Carrying Amount	$ (24,396)	(11,516)
Company's Share of unconsolidated real estate venture Income (Loss)	(8,683)	(6,570)	(6,102)
Unconsolidated Real Estate Venture Debt at 100%, gross	$ 184,263	185,000
PJP VII
Schedule of Equity Method Investments [Line Items]
Ownership Percentage	25.00%
Company's Share of unconsolidated real estate venture Income (Loss)			190
PJP II
Schedule of Equity Method Investments [Line Items]
Ownership Percentage	30.00%
Company's Share of unconsolidated real estate venture Income (Loss)			81
PJP VI
Schedule of Equity Method Investments [Line Items]
Ownership Percentage	25.00%
Company's Share of unconsolidated real estate venture Income (Loss)			(185)
4040 Wilson Venture
Schedule of Equity Method Investments [Line Items]
Ownership Percentage	50.00%				50.00%
Carrying Amount	$ 31,059	34,454
Company's Share of unconsolidated real estate venture Income (Loss)	(2,258)	(2,162)	(368)
Unconsolidated Real Estate Venture Debt at 100%, gross	$ 145,000	141,857
1919 Venture
Schedule of Equity Method Investments [Line Items]
Ownership Percentage	50.00%
Carrying Amount	$ 13,791	15,434
Company's Share of unconsolidated real estate venture Income (Loss)	427	59	328
Unconsolidated Real Estate Venture Debt at 100%, gross	$ 88,860	88,860
3025 JFK Venture
Schedule of Equity Method Investments [Line Items]
Ownership Percentage	55.00%
Carrying Amount	$ 56,370	0
Company's Share of unconsolidated real estate venture Income (Loss)	(118)	0	0
Unconsolidated Real Estate Venture Debt at 100%, gross	$ 0	0
JBG 51 N Street
Schedule of Equity Method Investments [Line Items]
Ownership Percentage	70.00%
Carrying Amount	$ 21,213	21,237
Company's Share of unconsolidated real estate venture Income (Loss)	(402)	(457)	(313)
Unconsolidated Real Estate Venture Debt at 100%, gross	$ 0	0
JBG 1250 First Street Office
Schedule of Equity Method Investments [Line Items]
Ownership Percentage	70.00%
Carrying Amount	$ 17,751	17,757
Company's Share of unconsolidated real estate venture Income (Loss)	(199)	(227)	$ (255)
Unconsolidated Real Estate Venture Debt at 100%, gross	$ 0	$ 0

INVESTMENT IN UNCONSOLIDATED _5

INVESTMENT IN UNCONSOLIDATED REAL ESTATE VENTURES - Summary of Financial Position of Real Estate Ventures (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Schedule of Equity Method Investments [Line Items]
Net property	$ 2,955,068	$ 2,966,005
Other assets	133,094	176,747
Other liabilities	48,683	47,573
Equity	1,701,219	1,804,648	$ 1,688,303	$ 1,811,028
Investment In Nonconsolidated Real Estate
Schedule of Equity Method Investments [Line Items]
Net property	1,563,263	1,520,804
Other assets	434,687	488,805
Other liabilities	331,947	333,049
Debt, net	956,668	956,688
Equity	$ 709,335	$ 719,872

INVESTMENT IN UNCONSOLIDATED _6

INVESTMENT IN UNCONSOLIDATED REAL ESTATE VENTURES - Summary of Results of Operations of Real Estate Ventures with Interests (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Schedule of Equity Method Investments [Line Items]
Revenue	$ 486,819	$ 534,852	$ 580,417
Operating expenses	(396,569)	(424,027)	(468,007)
Interest expense, net	(62,617)	(73,911)	(81,512)
Depreciation and amortization	(178,105)	(188,283)	(210,005)
Net income	12,366	307,326	34,529
Equity in loss of unconsolidated real estate ventures	(26,697)	(18,584)	(9,922)
Investment In Nonconsolidated Real Estate
Schedule of Equity Method Investments [Line Items]
Revenue	214,792	150,276	132,358
Operating expenses	(117,273)	(85,812)	(71,784)
Interest expense, net	(30,569)	(22,661)	(21,908)
Depreciation and amortization	(97,147)	(70,805)	(53,331)
Provision for impairment	(1,393)	0	(5,664)
Loss on early extinguishment of debt	0	0	(1,231)
Net income	(31,590)	(29,002)	(21,560)
Company's share of net loss	(25,972)	(18,540)	(9,865)
Basis adjustments and other	(725)	(44)	(57)
Equity in loss of unconsolidated real estate ventures	$ (26,697)	$ (18,584)	$ (9,922)

INVESTMENT IN UNCONSOLIDATED _7

INVESTMENT IN UNCONSOLIDATED REAL ESTATE VENTURES - Aggregate Principal Payments of Recourse and Non-recourse Debt Payable to Third-parties (Details) - Unconsolidated Real Estate Ventures $ in Thousands	Dec. 31, 2021USD ($)
Schedule of Equity Method Investments [Line Items]
2022	$ 8,543
2023	477,649
2024	330,317
2025	0
2026	145,000
Thereafter	0
Total principal payments	961,509
Net deferred financing costs	(5,923)
Net unamortized premiums/(discounts)	1,082
Outstanding indebtedness	$ 956,668

INVESTMENT IN UNCONSOLIDATED _8

INVESTMENT IN UNCONSOLIDATED REAL ESTATE VENTURES - 4040 Wilson Venture (Details) $ in Millions	3 Months Ended
	Dec. 31, 2021USD ($)aft²property	Jul. 31, 2013
Schedule of Equity Method Investments [Line Items]
Number of real estate properties | property	81
Area of real estate property | ft²	13,678,136
4040 Wilson Venture
Schedule of Equity Method Investments [Line Items]
Number of real estate properties | property	1
Area of real estate property | ft²	225,000
Land area | a	250
Ownership percentage	50.00%	50.00%
4040 Wilson Venture | Construction Loans
Schedule of Equity Method Investments [Line Items]
Long-term debt, gross | $	$ 150
4040 Wilson Venture | Secured Debt | Mortgage Loan Secured By Property
Schedule of Equity Method Investments [Line Items]
Long-term debt, gross | $	$ 155
4040 Wilson Venture | Secured Debt | Mortgage Loan Secured By Property | Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate
Schedule of Equity Method Investments [Line Items]
Variable interest rate	1.80%

INVESTMENT IN UNCONSOLIDATED _9

INVESTMENT IN UNCONSOLIDATED REAL ESTATE VENTURES - Brandywine - AI Venture (Details)	Nov. 09, 2021USD ($)ft²	Dec. 31, 2021USD ($)	Dec. 31, 2020USD ($)	Dec. 31, 2019USD ($)ft²
Schedule of Equity Method Investments [Line Items]
Net gain on real estate venture transactions		$ 2,973,000	$ 75,000	$ 11,639,000
Impairment of properties held for use		0	$ 0	0
Brandywine - AI Venture LLC | Fairview Properties
Schedule of Equity Method Investments [Line Items]
Provision for impairment on assets held for sale		1,400,000
Impairment of properties held for use				5,600,000
Brandywine - AI Venture LLC | Fairview Properties | Brandywine Realty Trust
Schedule of Equity Method Investments [Line Items]
Provision for impairment on assets held for sale		$ 700,000
Impairment of properties held for use				$ 2,800,000
Brandywine - AI Venture LLC | Falls Church, Virginia
Schedule of Equity Method Investments [Line Items]
Rentable square feet | ft²	183,618			180,659
Aggregate sales price	$ 27,600,000
Gross proceeds from sale	12,600,000
Net gain on real estate venture transactions	$ 3,000,000			$ 2,200,000
Debt, net				$ 26,000,000

INVESTMENT IN UNCONSOLIDATED_10

INVESTMENT IN UNCONSOLIDATED REAL ESTATE VENTURES - 3025 JFK Venture (Details) - 3025 JFK Venture $ in Millions	Feb. 02, 2021a	Dec. 31, 2021USD ($)	Jul. 23, 2021USD ($)	Feb. 02, 2021ft²	Feb. 02, 2021USD ($)	Feb. 02, 2021
Schedule of Equity Method Investments [Line Items]
Lease agreement term	99 years
Land area	1			1
Investment in real estate venture			$ 34.8		$ 34.8
Area of building to be constructed | ft²				570,000
Estimated project cost					287.3
Joint venture, funding committed by other party					$ 45.2
Ownership interest held by partner						45.00%
Ownership percentage						55.00%
Construction loan amount		$ 186.7	$ 186.7
Joint venture, funding committed		$ 20.5
LIBOR
Schedule of Equity Method Investments [Line Items]
Debt instrument, interest rate, stated percentage			3.50%
Interest rate, floor			0.25%

INVESTMENT IN UNCONSOLIDATED_11

INVESTMENT IN UNCONSOLIDATED REAL ESTATE VENTURES - Mid-Atlantic Office JV (Details) $ in Millions	Dec. 21, 2020USD ($)ft²property	Dec. 31, 2021USD ($)property
Schedule of Equity Method Investments [Line Items]
Number of real estate properties | property		81
Mid-Atlantic Office JV Loan
Schedule of Equity Method Investments [Line Items]
Proceeds from issuance of secured debt		$ 2.2
Secured construction loan with total borrowing capacity		$ 24.4
Mid-Atlantic Office Venture
Schedule of Equity Method Investments [Line Items]
Ownership percentage	40.00%	40.00%
Ownership percentage of total common equity	20.00%
Joint venture, funding from debt	$ 147.4
Proceeds from issuance of secured debt	$ 120.8
Mid-Atlantic Office Venture | Mid-Atlantic Office JV Loan | Maximum
Schedule of Equity Method Investments [Line Items]
Debt instrument, interest rate, stated percentage	5.60%
Mid-Atlantic Office Venture | LIBOR | Mid-Atlantic Office JV Loan
Schedule of Equity Method Investments [Line Items]
Variable interest rate	3.15%
Mid-Atlantic Office Venture | Preferred Equity Securities
Schedule of Equity Method Investments [Line Items]
Ownership percentage	25.00%
Investment in real estate venture	$ 20
Mid-Atlantic Office Venture | Common Equity Securities
Schedule of Equity Method Investments [Line Items]
Ownership percentage	15.00%
Mid-Atlantic Office Venture | Office Properties
Schedule of Equity Method Investments [Line Items]
Number of real estate properties | property	12
Rentable square feet | ft²	1,128,645
Aggregate sales price	$ 192.9
Mid-Atlantic Office Venture | Office Properties | Philadelphia CBD
Schedule of Equity Method Investments [Line Items]
Number of real estate properties | property	9
Mid-Atlantic Office Venture | Office Properties | Metropolitan Washington, D.C.
Schedule of Equity Method Investments [Line Items]
Number of real estate properties | property	3

INVESTMENT IN UNCONSOLIDATED_12

INVESTMENT IN UNCONSOLIDATED REAL ESTATE VENTURES - Commerce Square Venture (Details)	Dec. 31, 2021property	Jul. 21, 2021property	Dec. 21, 2020ft²	Jul. 21, 2020ft²
Schedule of Equity Method Investments [Line Items]
Sale of ownership interest percentage			60.00%
Number of real estate properties	81
Commerce Square
Schedule of Equity Method Investments [Line Items]
Sale of ownership interest percentage				30.00%
Commerce Square | Office Properties
Schedule of Equity Method Investments [Line Items]
Rentable square feet | ft²			1,896,142	1,896,142
Number of real estate properties		2
Commerce Square
Schedule of Equity Method Investments [Line Items]
Ownership percentage	70.00%
Commerce Square | Preferred Equity Securities
Schedule of Equity Method Investments [Line Items]
Ownership percentage	32.00%
Commerce Square | Common Equity Securities
Schedule of Equity Method Investments [Line Items]
Ownership percentage	38.00%

INVESTMENT IN UNCONSOLIDATED_13

INVESTMENT IN UNCONSOLIDATED REAL ESTATE VENTURES - PJP Ventures (Details) $ in Thousands	Oct. 29, 2019USD ($)ft²property	Dec. 31, 2021USD ($)ft²	Dec. 31, 2020USD ($)	Dec. 31, 2019USD ($)
Schedule of Equity Method Investments [Line Items]
Area of real estate property | ft²		13,678,136
Proceeds from the sale of properties		$ 10,303	$ 278,114	$ 41,795
Net gain on real estate venture transactions		$ 2,973	$ 75	$ 11,639
PJP II, PJP VII, And PJP VII | Charlottesville VA
Schedule of Equity Method Investments [Line Items]
Number of properties contributed to joint venture | property	3
Area of real estate property | ft²	204,347
Aggregate sales price	$ 51,000
Proceeds from the sale of properties	9,100
Net gain on real estate venture transactions	$ 8,000
PJP II, PJP VII, And PJP VII | Charlottesville VA | Minimum
Schedule of Equity Method Investments [Line Items]
Ownership percentage	25.00%
PJP II, PJP VII, And PJP VII | Charlottesville VA | Maximum
Schedule of Equity Method Investments [Line Items]
Ownership percentage	30.00%

INVESTMENT IN UNCONSOLIDATED_14

INVESTMENT IN UNCONSOLIDATED REAL ESTATE VENTURES - Hernadon Innovation Center Metro Portfolio Venture, LLC (Details)	Apr. 12, 2019USD ($)	Apr. 11, 2019USD ($)	Mar. 29, 2019USD ($)property	Dec. 31, 2021ft²property
Schedule of Equity Method Investments [Line Items]
Area of real estate property | ft²				13,678,136
Herndon Innovation Center Metro Portfolio Venture, LLC
Schedule of Equity Method Investments [Line Items]
Ownership percentage				15.00%
Herndon Innovation Center Metro Portfolio Venture, LLC | Secured Debt
Schedule of Equity Method Investments [Line Items]
Debt instrument, face amount			$ 134,100,000
Number of properties used to secure debt | property			4
Proceeds from issuance of debt		$ 94,200,000	$ 113,100,000
Herndon Innovation Center Metro Portfolio Venture, LLC | Distributions From Loan One | Secured Debt
Schedule of Equity Method Investments [Line Items]
Proceeds from issuance of debt	$ 16,700,000
Variable interest rate			1.95%
Herndon Innovation Center Metro Portfolio Venture, LLC | Distributions From Loan One | Minimum | Secured Debt
Schedule of Equity Method Investments [Line Items]
Capped interest rate	5.45%
Herndon Innovation Center Metro Portfolio Venture, LLC | Distributions From Loan One | Maximum | Secured Debt
Schedule of Equity Method Investments [Line Items]
Capped interest rate	6.45%
Herndon Innovation Center Metro Portfolio Venture, LLC | Distributions From Loan Two | Secured Debt
Schedule of Equity Method Investments [Line Items]
Debt instrument, face amount		$ 115,300,000
Proceeds from issuance of debt	$ 13,800,000
Variable interest rate		1.80%
Herndon Innovation Center Metro Portfolio Venture, LLC | Distributions From Loan Two | Maximum | Secured Debt
Schedule of Equity Method Investments [Line Items]
Capped interest rate		6.30%
Herndon Innovation Center Metro Portfolio Venture, LLC | Metropolitan Washington, D.C. - Office
Schedule of Equity Method Investments [Line Items]
Number of properties contributed to joint venture | property				8
Area of real estate property | ft²				1,293,197
Herndon Innovation Center Metro Portfolio Venture, LLC | Metropolitan Washington, D.C. - Office | Minimum
Schedule of Equity Method Investments [Line Items]
Ownership percentage				15.00%
Herndon Innovation Center Metro Portfolio Venture, LLC | Metropolitan Washington, D.C. - Office | Maximum
Schedule of Equity Method Investments [Line Items]
Ownership percentage				85.00%

INVESTMENT IN UNCONSOLIDATED_15

INVESTMENT IN UNCONSOLIDATED REAL ESTATE VENTURES - MAP Venture (Details) - MAP Venture $ in Millions	12 Months Ended
	Dec. 31, 2021USD ($)ft²property
Schedule of Equity Method Investments [Line Items]
Ground lease annual payments | $	$ 11.9
Ground lease annual rent expense increase percentage through November 2025	2.50%
Ground lease annual rent expense increase after November 2025	2.50%
Variable Interest Entity, Not Primary Beneficiary
Schedule of Equity Method Investments [Line Items]
Number of office properties owned | property	58
Rentable square feet | ft²	3,924,783

INVESTMENT IN UNCONSOLIDATED_16

INVESTMENT IN UNCONSOLIDATED REAL ESTATE VENTURES - 1919 Ventures (Details) - 1919 Venture ft² in Thousands	12 Months Ended
	Dec. 31, 2021ft²storyapartmentcar
Schedule of Equity Method Investments [Line Items]
Number of floors of a building | story	29
Square foot of contemporary glass tower development	455
Number of luxury apartments | apartment	321
Square feet of commercial space	24
Number of car structured parking facility | car	215

INVESTMENT IN UNCONSOLIDATED_17

INVESTMENT IN UNCONSOLIDATED REAL ESTATE VENTURES - JGB Ventures (Details)	Dec. 31, 2021aproperty
Schedule of Equity Method Investments [Line Items]
Number of real estate properties | property	81
JBG 51 N Street
Schedule of Equity Method Investments [Line Items]
Ownership percentage	70.00%
Area owned by real estate venture of undeveloped parcels of land | a	0.9
JBG 51 N Street | JBG Ventures
Schedule of Equity Method Investments [Line Items]
Ownership percentage	30.00%
JBG 1250 First Street Office
Schedule of Equity Method Investments [Line Items]
Ownership percentage	70.00%
Area owned by real estate venture of undeveloped parcels of land | a	0.5
JBG 1250 First Street Office | JBG Ventures
Schedule of Equity Method Investments [Line Items]
Ownership percentage	30.00%
JBG Ventures
Schedule of Equity Method Investments [Line Items]
Number of real estate properties | property	2

DEBT AND PREFERRED EQUITY INV_2

DEBT AND PREFERRED EQUITY INVESTMENTS (Details)	3 Months Ended	12 Months Ended
	Sep. 30, 2021USD ($)	Dec. 31, 2020USD ($)property	Dec. 31, 2018USD ($)	Dec. 31, 2021property	Sep. 03, 2021USD ($)
Summary of Investment Holdings [Line Items]
Number of real estate properties | property				81
Austin Preferred Equity Investment | Notes Receivable
Summary of Investment Holdings [Line Items]
Note receivable		$ 50,000,000
Number of real estate properties | property		2
Notes receivable, interest rate		9.00%
Extension option term		1 year
Note receivable repurchased amount					$ 50,000,000
Gain on financing receivable redemption	$ 2,800,000
1919 Venture
Summary of Investment Holdings [Line Items]
Note receivable			$ 44,400,000
Notes receivable, interest rate			4.00%
Debt, net			$ 44,400,000
Repayment of construction loan			$ 88,800,000

LEASES - Lessor Accounting Matu

LEASES - Lessor Accounting Maturities (Details) $ in Thousands	Dec. 31, 2021USD ($)
Lessor, Operating Lease, Payments, Fiscal Year Maturity [Abstract]
2022	$ 328,553
2023	327,981
2024	304,240
2025	274,216
2026	249,045
Thereafter	$ 952,898

LEASES - Narrative (Details)

LEASES - Narrative (Details)	12 Months Ended
	Dec. 31, 2021leaseproperty
Lessee, Lease, Description [Line Items]
Number of ground leases considered operating lease | lease	6
Number of properties subject to ground leases | property	3
Minimum
Lessee, Lease, Description [Line Items]
Lease terms	8 years
Maximum
Lessee, Lease, Description [Line Items]
Lease terms	63 years

LEASES - Lease Cost (Details)

LEASES - Lease Cost (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Leases [Abstract]
Fixed lease cost	$ 2,100	$ 2,100
Variable lease cost	43	45
Total	$ 2,143	$ 2,145
Weighted-average remaining lease term (years)	55 years 2 months 12 days	55 years 10 months 24 days
Weighted-average discount rate	6.30%	6.30%

LEASES - Lessee Accounting Matu

LEASES - Lessee Accounting Maturities (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Minimum Rent
2022	$ 1,248
2023	1,263
2024	1,305
2025	1,321
2026	1,338
Thereafter	107,793
Total lease payments	114,268
Less: Imputed interest	91,306
Present value of operating lease liabilities	$ 22,962	$ 22,758

DEFERRED COSTS - Deferred Costs

DEFERRED COSTS - Deferred Costs (Assets) (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Deferred Costs [Line Items]
Leasing costs, Total Cost	$ 143,895	$ 139,207
Total Cost	150,194	145,506
Leasing costs, Accumulated Amortization	(57,445)	(55,656)
Total, Accumulated Amortization	(63,332)	(60,650)
Leasing costs, Deferred Costs, net	86,450	83,551
Deferred Costs	86,862	84,856
Financing costs - Unsecured Credit Facility
Deferred Costs [Line Items]
Financing costs, Total Cost	6,299	6,299
Financing costs, Accumulated Amortization	(5,887)	(4,994)
Financing costs, Deferred Costs, net	$ 412	$ 1,305

DEFERRED COSTS - Narrative (Det

DEFERRED COSTS - Narrative (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Deferred Costs (Textual) [Abstract]
Capitalized internal direct leasing costs	$ 2.1	$ 1.6	$ 1.7

INTANGIBLE ASSETS AND LIABILI_3

INTANGIBLE ASSETS AND LIABILITIES - Intangible Assets (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Intangible assets, net:
Total Cost	$ 73,029	$ 94,173
Accumulated Amortization	(44,473)	(45,603)
Total	28,556	48,570
Intangible liabilities, net:
Total Cost	27,025	31,263
Accumulated Amortization	(14,044)	(12,815)
Total	12,981	18,448
In-place lease value
Intangible assets, net:
Total Cost	72,376	91,552
Accumulated Amortization	(44,066)	(43,400)
Total	28,310	48,152
Tenant relationship value
Intangible assets, net:
Total Cost	167	2,091
Accumulated Amortization	(97)	(1,938)
Total	70	153
Above market leases acquired
Intangible assets, net:
Total Cost	486	530
Accumulated Amortization	(310)	(265)
Total	$ 176	$ 265

INTANGIBLE ASSETS AND LIABILI_4

INTANGIBLE ASSETS AND LIABILITIES - Narrative (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Tenant Move Outs Prior To End Of Lease Term
Finite-Lived Intangible Assets [Line Items]
Intangible assets written off through accelerated amortization	$ 3.6	$ 0.3	$ 4.5
Tenant Move-Outs
Finite-Lived Intangible Assets [Line Items]
Intangible assets written off through accelerated amortization	$ 0.6	$ 0.1	$ 2.2

INTANGIBLE ASSETS AND LIABILI_5

INTANGIBLE ASSETS AND LIABILITIES - Annual Amortization of Intangible Assets, Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Assets
2022	$ 9,642
2023	6,724
2024	4,433
2025	3,255
2026	1,195
Thereafter	3,307
Total	28,556	$ 48,570
Liabilities
2022	2,588
2023	1,540
2024	1,321
2025	1,044
2026	754
Thereafter	5,734
Total	$ 12,981	$ 18,448

DEBT OBLIGATIONS - Consolidated

DEBT OBLIGATIONS - Consolidated Debt Obligations Outstanding (Details) - Unsecured Debt - USD ($)	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Consolidated debt obligations
Long-term debt, gross	$ 1,851,610,000	$ 1,828,610,000
Plus: premiums/(discounts), net	8,187,000	10,137,000
Net deferred financing costs	(6,211,000)	(8,152,000)
Total Debt Obligations	1,853,586,000	1,830,595,000
$600 million Unsecured Credit Facility
Consolidated debt obligations
Debt instrument, face amount	600,000,000
Long-term debt, gross	$ 23,000,000	0
Seven-Year Term Loan - Swapped to fixed
Consolidated debt obligations
Debt instrument, term	7 years
Long-term debt, gross	$ 250,000,000	250,000,000
Effective interest rate	2.87%
$350.0M 3.95% Guaranteed Notes due 2023
Consolidated debt obligations
Debt instrument, face amount	$ 350,000,000
Debt instrument, interest rate, stated percentage	3.95%
Long-term debt, gross	$ 350,000,000	350,000,000
Effective interest rate	3.87%
$350.0M 4.10% Guaranteed Notes due 2024
Consolidated debt obligations
Debt instrument, face amount	$ 350,000,000
Debt instrument, interest rate, stated percentage	4.10%
Long-term debt, gross	$ 350,000,000	350,000,000
Effective interest rate	3.78%
$450.0M 3.95% Guaranteed Notes due 2027
Consolidated debt obligations
Debt instrument, face amount	$ 450,000,000
Debt instrument, interest rate, stated percentage	3.95%
Long-term debt, gross	$ 450,000,000	450,000,000
Effective interest rate	4.03%
$350.0M 4.55% Guaranteed Notes due 2029
Consolidated debt obligations
Debt instrument, face amount	$ 350,000,000
Debt instrument, interest rate, stated percentage	4.55%
Long-term debt, gross	$ 350,000,000	350,000,000
Effective interest rate	4.30%
Indenture IA (Preferred Trust I)
Consolidated debt obligations
Long-term debt, gross	$ 27,062,000	27,062,000
Indenture IB (Preferred Trust I)
Consolidated debt obligations
Long-term debt, gross	25,774,000	25,774,000
Indenture II (Preferred Trust II)
Consolidated debt obligations
Long-term debt, gross	$ 25,774,000	$ 25,774,000
LIBOR | $600 million Unsecured Credit Facility
Consolidated debt obligations
Variable interest rate	1.10%
LIBOR | Indenture IA (Preferred Trust I)
Consolidated debt obligations
Variable interest rate	1.25%
LIBOR | Indenture IB (Preferred Trust I)
Consolidated debt obligations
Variable interest rate	1.25%
LIBOR | Indenture II (Preferred Trust II)
Consolidated debt obligations
Variable interest rate	1.25%

DEBT OBLIGATIONS - Narrative (D

DEBT OBLIGATIONS - Narrative (Details)	Jul. 17, 2018USD ($)extension	Dec. 31, 2021USD ($)	Dec. 31, 2020USD ($)
Debt Instrument [Line Items]
Line of credit		$ 23,000,000	$ 0
Financing costs - Unsecured Credit Facility
Debt Instrument [Line Items]
Line of credit		$ 23,000,000
Long-term debt, weighted average interest rate		1.21%	1.48%
Interest expense borrowings		$ 400,000	$ 500,000
Financing costs - Unsecured Credit Facility | 2018 Credit Facility
Debt Instrument [Line Items]
Debt instrument, number of extensions | extension	2
Debt instrument, extension term duration	6 months
Debt financing costs	$ 2,700,000
Minimum credit Spread on a LIBOR rate loan		0.00%
Maximum credit spread on a LIBOR rate Loan		0.45%
Commitment fee percentage		0.25%
Minimum fixed charge coverage ratio		1.5
Maximum leverage ratio		0.60
Maximum unsecured indebtedness to unencumbered asset value ratio		0.60
Maximum secured indebtedness to total asset value ratio		0.40
Minimum unencumbered cash flow to interest expense on unsecured debt ratio		1.75
Maximum percent of payments of dividends and distributions		95.00%
Financing costs - Unsecured Credit Facility | 2018 Credit Facility | Minimum
Debt Instrument [Line Items]
Commitment fee percentage		0.125%
Financing costs - Unsecured Credit Facility | 2018 Credit Facility | Maximum
Debt Instrument [Line Items]
Commitment fee percentage		0.30%
Financing costs - Unsecured Credit Facility | 2018 Credit Facility | LIBOR
Debt Instrument [Line Items]
Variable interest rate		1.10%
Basis spread on variable rate		1.00%
Financing costs - Unsecured Credit Facility | 2018 Credit Facility | LIBOR | Minimum
Debt Instrument [Line Items]
Variable interest rate		0.775%
Financing costs - Unsecured Credit Facility | 2018 Credit Facility | LIBOR | Maximum
Debt Instrument [Line Items]
Variable interest rate		1.45%
Financing costs - Unsecured Credit Facility | 2018 Credit Facility | Federal Funds Rate
Debt Instrument [Line Items]
Basis spread on variable rate		0.50%
Unsecured Debt | $600 million Unsecured Credit Facility
Debt Instrument [Line Items]
Debt instrument, face amount		$ 600,000,000
Maximum borrowing capacity	$ 600,000,000
Unsecured Debt | $600 million Unsecured Credit Facility | LIBOR
Debt Instrument [Line Items]
Variable interest rate		1.10%

DEBT OBLIGATIONS - Aggregate Sc

DEBT OBLIGATIONS - Aggregate Scheduled Principal Payments of Debt Obligation, Excluding Amortization of Discounts and Premiums (Details) - Unsecured Debt - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Debt Instrument [Line Items]
2022	$ 273,000
2023	350,000
2024	350,000
2025	0
2026	0
Thereafter	878,610
Total principal payments	1,851,610	$ 1,828,610
Net unamortized premiums/(discounts)	8,187	10,137
Net deferred financing costs	(6,211)	(8,152)
Debt, net	$ 1,853,586	$ 1,830,595

FAIR VALUE OF FINANCIAL INSTR_3

FAIR VALUE OF FINANCIAL INSTRUMENTS - Financial Instruments for which Estimates of Fair Value Differ from Carrying Amounts (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Carrying Amount
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Note receivable	$ 44,430	$ 94,430
Fair Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Note receivable, fair value	45,230	97,372
Unsecured notes payable
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Deferred financing costs, net	6,211	8,152
Unsecured notes payable | Carrying Amount
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Unsecured notes payable	1,502,368	1,502,901
Deferred financing costs, net	5,800	7,200
Unsecured notes payable | Fair Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt instrument, fair value	1,588,780	1,607,310
Variable rate debt | Carrying Amount
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Variable rate debt	351,218	327,694
Deferred financing costs, net	400	900
Variable rate debt | Fair Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt instrument, fair value	$ 344,754	$ 308,838

DERIVATIVE FINANCIAL INSTRUME_3

DERIVATIVE FINANCIAL INSTRUMENTS (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Derivatives, Fair Value [Line Items]
Derivative, notional amount	$ 250,000	$ 275,774
2.868% Interest Rate Swap Maturing October 8, 2022 | Cash Flow Hedging
Derivatives, Fair Value [Line Items]
Derivative liability, notional amount	$ 250,000	250,000
Strike	2.868%
Derivative liability, fair value, gross liability	$ (2,461)	(6,627)
3.300% Interest Rate Swap Maturing January 30, 2021 | Cash Flow Hedging
Derivatives, Fair Value [Line Items]
Derivative liability, notional amount	$ 0	25,774
Strike	3.30%
Derivative liability, fair value, gross liability	$ 0	$ (120)

LIMITED PARTNERS' NONCONTROLL_2

LIMITED PARTNERS' NONCONTROLLING INTERESTS IN THE PARENT COMPANY (Details) - USD ($) $ in Millions	Dec. 31, 2021	Dec. 31, 2020
Noncontrolling Interest [Abstract]
Aggregate amount related to non-controlling interests classified within equity	$ 8.2	$ 10.5
Settlement value of non controlling interest in operating partnership	$ 11.1	$ 11.7

BENEFICIARIES' EQUITY OF THE _3

BENEFICIARIES' EQUITY OF THE PARENT COMPANY - Number of Shares and Net Income Used to Calculate Basic and Diluted Earnings per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Numerator
Net income	$ 12,366	$ 307,326	$ 34,529
Net income attributable to noncontrolling interests, Basic	(77)	(1,799)	(262)
Net income attributable to noncontrolling interests, Diluted	(77)	(1,799)	(262)
Nonforfeitable dividends allocated to unvested restricted shareholders, Basic	(421)	(410)	(396)
Nonforfeitable dividends allocated to unvested restricted shareholders, Diluted	(421)	(410)	(396)
Net income attributable to Common Shareholders/ Unitholders of Brandywine Realty Trust	11,868	305,117	33,871
Net income attributable to common shareholders, Diluted	$ 11,868	$ 305,117	$ 33,871
Denominator
Basic weighted average shares outstanding (in shares)	170,878,185	171,926,079	176,132,941
Contingent securities/Share based compensation (in shares)	1,395,055	390,997	553,872
Diluted weighted average shares outstanding (in shares)	172,273,240	172,317,076	176,686,813
Earnings per Common Share:
Net income attributable to common shareholders, Basic (in dollars per share)	$ 0.07	$ 1.77	$ 0.19
Net income attributable to common shareholders, Diluted (in dollars per share)	$ 0.07	$ 1.77	$ 0.19

BENEFICIARIES' EQUITY OF THE _4

BENEFICIARIES' EQUITY OF THE PARENT COMPANY - Narrative (Details) - USD ($)	Dec. 07, 2021	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019	Jan. 03, 2019	Jan. 10, 2017
Class of Stock [Line Items]
Dividends, common stock	$ 32,800,000
Preferred shares authorized (in shares)		20,000,000	20,000,000
Preferred shares outstanding (in shares)		0	0
shares repurchased and retired (in units)		$ 0			$ 150,000,000
Repurchased and retired (in shares)			6,248,483	1,337,169
Share price (in usd per share)			$ 9.60	$ 12.92
Repurchased and retired, value			$ 59,999,000	$ 17,281,000
Common stock, shares authorized (in shares)		400,000,000	400,000,000
Common shares remain available for issuance (in shares)		0
Offering Program
Class of Stock [Line Items]
Common stock, shares authorized (in shares)						16,000,000
Common shares issued under offering program (in shares)			0	0
Commerce Square
Class of Stock [Line Items]
Units issued to acquire noncontrolling interest (in units)		226,695
Percent of noncontrolling interest acquired		1.00%
Dividend Declared
Class of Stock [Line Items]
Dividends payable, amount per share (in usd per share)	$ 0.19
Redeemable Common Limited Partnership Units
Class of Stock [Line Items]
Redeemable common limited partnership units (in shares)		823,983	981,634	981,634

PARTNERS' EQUITY OF THE PAREN_3

PARTNERS' EQUITY OF THE PARENT COMPANY - Number of Units and Net Income Used to Calculate Basic and Diluted Earnings Per Common Partnership Unit (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Numerator
Net income	$ 12,366	$ 307,326	$ 34,529
Nonforfeitable dividends allocated to unvested restricted shareholders, Basic	(421)	(410)	(396)
Nonforfeitable dividends allocated to unvested restricted shareholders, Diluted	$ (421)	$ (410)	$ (396)
Denominator
Basic weighted average shares outstanding (in shares)	170,878,185	171,926,079	176,132,941
Contingent securities/Share based compensation (in shares)	1,395,055	390,997	553,872
Diluted weighted average shares outstanding (in shares)	172,273,240	172,317,076	176,686,813
Earnings per Common Partnership Unit:
Net income attributable to common shareholders, Basic (in dollars per share)	$ 0.07	$ 1.77	$ 0.19
Net income attributable to common shareholders, Diluted (in dollars per share)	$ 0.07	$ 1.77	$ 0.19
BRANDYWINE OPERATING PARTNERSHIP, L.P.
Numerator
Net income	$ 12,366	$ 307,326	$ 34,529
Net income attributable to noncontrolling interests	3	(20)	(69)
Nonforfeitable dividends allocated to unvested restricted shareholders, Basic	(421)	(410)	(396)
Nonforfeitable dividends allocated to unvested restricted shareholders, Diluted	(421)	(410)	(396)
Net income attributable to common unitholders, Basic	11,948	306,896	34,064
Net income attributable to common unitholders, Diluted	$ 11,948	$ 306,896	$ 34,064
Denominator
Basic weighted average shares outstanding (in shares)	171,770,843	172,907,713	177,114,932
Contingent securities/Share based compensation (in shares)	1,395,055	390,997	553,872
Diluted weighted average shares outstanding (in shares)	173,165,898	173,298,710	177,668,804
Earnings per Common Partnership Unit:
Net income attributable to common shareholders, Basic (in dollars per share)	$ 0.07	$ 1.77	$ 0.19
Net income attributable to common shareholders, Diluted (in dollars per share)	$ 0.07	$ 1.77	$ 0.19

PARTNERS' EQUITY OF THE PAREN_4

PARTNERS' EQUITY OF THE PARENT COMPANY - Narrative (Details) - USD ($)	Dec. 07, 2021	Jan. 10, 2017	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019	Jan. 03, 2019
Earnings Per Common Partnership Unit [Line Items]
Dividends, common stock	$ 32,800,000
shares repurchased and retired (in units)			$ 0			$ 150,000,000
Repurchased and retired (in shares)				6,248,483	1,337,169
Share price (in usd per share)				$ 9.60	$ 12.92
Repurchased and retired, value				$ 59,999,000	$ 17,281,000
Common stock, par or stated value per share (in usd per share)			$ 0.01	$ 0.01
Common stock, shares authorized (in shares)			400,000,000	400,000,000
Common shares remain available for issuance (in shares)			0
Commerce Square
Earnings Per Common Partnership Unit [Line Items]
Percent of noncontrolling interest acquired			1.00%
Shelf Registration
Earnings Per Common Partnership Unit [Line Items]
Sale of Stock, Number of Shares Issued in Transaction			226,695
Offering Program
Earnings Per Common Partnership Unit [Line Items]
Common stock, shares authorized (in shares)		16,000,000
Upfront costs		$ 200,000
Dividend Declared
Earnings Per Common Partnership Unit [Line Items]
Dividends payable (in dollars per share)	$ 0.19
Class A Units
Earnings Per Common Partnership Unit [Line Items]
Redeemable limited partnership unit price (in dollars per share)			$ 13.42	$ 11.91	$ 15.75
Limited partners' capital account, units outstanding (in units)			823,983		981,634
BRANDYWINE OPERATING PARTNERSHIP, L.P.
Earnings Per Common Partnership Unit [Line Items]
Preferred units, outstanding (in units)			0	0
Repurchase program, number of mirror unit of operating partnership retired for each common share repurchased			1
Redeemable limited partnership units issued (in units)			823,983	981,634
Redeemable limited partnership units outstanding (in units)			823,983	981,634

SHARE BASED COMPENSATION, 401_3

SHARE BASED COMPENSATION, 401(K) PLAN AND DEFERRED COMPENSATION - Narrative (Details)	Mar. 04, 2021shares	Feb. 01, 2021shares	Dec. 31, 2021USD ($)shares	Dec. 31, 2020USD ($)shares	Dec. 31, 2019USD ($)shares	May 18, 2021shares	Feb. 23, 2021installmentshares	Jan. 20, 2021$ / shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Defined contribution plan, maximum annual contribution per employee, percent			100.00%
Defined contribution plan, employer discretionary contribution amount | $			$ 400,000	$ 500,000	$ 400,000
Number of vesting installments | installment							3
Number of shares to be issued under deferred compensation plan included in total shares outstanding			1,200,000
Restricted Share Rights Awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted share rights outstanding (in shares)			474,978	488,735
Unrecognized compensation expenses | $			$ 1,800,000
Weighted average period over which options will be recognized			1 year 10 months 24 days
Share-based compensation expense | $			$ 4,100,000	$ 4,300,000	3,900,000
Share-based compensation expense, capitalized | $			$ 500,000	400,000	300,000
Granted (in shares)	252,278		343,179
Number of restricted share right will get settled for common share	1
Accumulated service period for voluntary termination	15 years
Restricted Share Rights Awards | Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period			1 year
Restricted Share Rights Awards | Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period	3 years		3 years
Restricted Performance Share Units Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period		3 years
Unrecognized compensation expenses | $			$ 6,300,000
Weighted average period over which options will be recognized			1 year 6 months
Share-based compensation expense | $			$ 4,300,000	3,000,000	4,200,000
Share-based compensation expense, capitalized | $			$ 500,000	$ 400,000	$ 600,000
Common shares issued for share based compensation		82,513
Dividends payable (in dollars per share) | $ / shares								$ 0.19
Restricted Performance Share Units Plan | Executive Officers
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted share rights outstanding (in shares)			890,448	525,669
Granted (in shares)			380,957
Performance earning potential			200.00%
Outperformance feature measurement term			3 years
Additional vesting period			2 years
Restricted Performance Share Units Plan | Executive Officers | 2020 Awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Awards issuable under outperformance feature (in shares)			388,840	316,236
Restricted Performance Share Units Plan | Executive Officers | 2019 Awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Awards issuable under outperformance feature (in shares)					228,858
Restricted Performance Share Units Plan | Non-Officer Employees
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted share rights outstanding (in shares)						41,634	49,267
Employee Share Purchase Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation expense | $			$ 100,000	$ 100,000	$ 100,000
Share-based compensation, percentage of closing price			85.00%
Maximum participant contribution, percentage of compensation			20.00%
Maximum participant contribution, dollar amount | $			$ 50,000
Aggregate share-based awards awarded to executives			1,250,000
Stock issued during period, value, employee stock purchase plan | $			$ 600,000	$ 400,000	$ 500,000
Share-based compensation arrangement by share-based payment award, discount from market price, purchase			15.00%

SHARE BASED COMPENSATION, 401_4

SHARE BASED COMPENSATION, 401(K) PLAN AND DEFERRED COMPENSATION - Restricted Share Activity (Details) - Restricted Share Rights Awards - $ / shares	Mar. 04, 2021	Dec. 31, 2021
Shares
Beginning balance (in shares)		488,735
Granted (in shares)	252,278	343,179
Vested (in shares)		(339,579)
Forfeited (in shares)		(17,357)
Ending balance (in shares)		474,978
Weighted Average Grant Date Fair Value
Non-vested at beginning of year, Weighted Average Grant Date Fair Value (in dollars per shares)		$ 15.19
Granted, Weighted Average Grant Date Fair Value (in dollars per shares)		12.72
Vested, Weighted Average Grant Date Fair Value (in dollars per shares)		15.12
Forfeited, Weighted Average Grant Date Fair Value (in dollars per shares)		13.55
Non-vested at end of year, Weighted Average Grant Date Fair Value (in dollars per shares)		$ 13.51

SHARE BASED COMPENSATION, 401_5

SHARE BASED COMPENSATION, 401(K) PLAN AND DEFERRED COMPENSATION - Restricted Performance Share Units (Details) - Restricted Performance Share Units Plan - Executive Officers - USD ($) $ in Thousands	Mar. 05, 2021	Mar. 05, 2020	Feb. 21, 2019	Dec. 31, 2021
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Beginning balance (in shares)				525,669
Granted (in shares)				380,957
Units Cancelled (in shares)				(16,178)
Ending balance (in shares)				890,448
February 21, 2019 RSPU Grant
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Beginning balance (in shares)				206,069
Granted (in shares)				0
Units Cancelled (in shares)				(3,837)
Ending balance (in shares)				202,232
Total number of shares authorized for issuance (in shares)			213,728
Fair Value of Units on Grant Date			$ 4,627
March 5, 2020 RSPU Grant
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Beginning balance (in shares)				319,600
Granted (in shares)				0
Units Cancelled (in shares)				(5,545)
Ending balance (in shares)				314,055
Total number of shares authorized for issuance (in shares)		319,600
Fair Value of Units on Grant Date		$ 5,389
March 5, 2021 RSPU Grant
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Beginning balance (in shares)				0
Granted (in shares)				380,957
Units Cancelled (in shares)				(6,796)
Ending balance (in shares)				374,161
Total number of shares authorized for issuance (in shares)	380,957
Fair Value of Units on Grant Date	$ 6,389

DISTRIBUTIONS (Details)

DISTRIBUTIONS (Details) - $ / shares	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Distributions [Abstract]
Common share distributions payments of ordinary dividends (in usd per share)	$ 0.64	$ 0.41	$ 0.62
Common share distributions capital gain (in usd per share)	0.01	0.35	0
Common share distributions non-taxable distributions (in usd per share)	0.11	0	0.14
Common stock dividends per share paid (in usd per share)	$ 0.76	$ 0.76	$ 0.76
Percentage classified as ordinary income	83.90%	53.90%	81.00%
Percentage classified as capital gain	1.20%	46.10%	0.00%
Percentage classified as non-taxable distribution	14.90%	0.00%	19.00%

INCOME TAXES AND TAX CREDIT T_2

INCOME TAXES AND TAX CREDIT TRANSACTIONS (Details) - USD ($)	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Income Tax Examination [Line Items]
Accruals for tax uncertainties	$ 0	$ 0
Deferred income tax expense (benefit)	0	0	$ 100,000
Current income tax expense (benefit)	0	(200,000)	$ (100,000)
Other Assets
Income Tax Examination [Line Items]
Deferred tax assets	$ 0	$ 0

ACCUMULATED OTHER COMPREHENSI_3

ACCUMULATED OTHER COMPREHENSIVE INCOME (LOSS) - Components of Accumulated Other Comprehensive Income (Loss) (Details) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Parent Company
Beneficiaries' Equity, beginning balance		$ 1,804,648	$ 1,688,303	$ 1,811,028
Change in fair market value during year		4,817	(5,972)	(8,210)
Allocation of unrealized (gains)/losses on derivative financial instruments to noncontrolling interests		(28)	29	41
Amortization of interest rate contracts reclassified from comprehensive income to interest expense	[1]	752	752	770
Beneficiaries' Equity, ending balance		1,701,219	1,804,648	1,688,303
Operating Partnership
Change in fair market value during year		4,817	(5,972)	(8,210)
Amortization of interest rate contracts reclassified from comprehensive income to interest expense	[1]	752	752	770
BRANDYWINE OPERATING PARTNERSHIP, L.P.
Parent Company
Change in fair market value during year		4,817	(5,972)	(8,210)
Amortization of interest rate contracts reclassified from comprehensive income to interest expense	[1]	752	752	770
Operating Partnership
Partners' Equity, beginning balance		1,793,082	1,672,915	1,798,508
Change in fair market value during year		4,817	(5,972)	(8,210)
Amortization of interest rate contracts reclassified from comprehensive income to interest expense	[1]	752	752	770
Partners' Equity, ending balance		1,690,079	1,793,082	1,672,915
Accumulated Other Comprehensive Income (Loss)
Parent Company
Beneficiaries' Equity, beginning balance		(7,561)	(2,370)	5,029
Beneficiaries' Equity, ending balance		(2,020)	(7,561)	(2,370)
Accumulated Other Comprehensive Income (Loss) | BRANDYWINE OPERATING PARTNERSHIP, L.P.
Operating Partnership
Partners' Equity, beginning balance		(7,935)	(2,715)	4,725
Partners' Equity, ending balance		$ (2,366)	$ (7,935)	$ (2,715)
[1]	Amounts reclassified from comprehensive income to interest expense within the Consolidated Statements of Operations.

ACCUMULATED OTHER COMPREHENSI_4

ACCUMULATED OTHER COMPREHENSIVE INCOME (LOSS) - Narrative (Details) $ in Millions	Dec. 31, 2021USD ($)
Stockholders' Equity Note [Abstract]
Losses expected to be reclassified from AOCI into interest expense within the next twelve months	$ 0.6

SEGMENT INFORMATION - Narrative

SEGMENT INFORMATION - Narrative (Details)	12 Months Ended
	Dec. 31, 2021segment
Segment Reporting [Abstract]
Number of reportable segments	5

SEGMENT INFORMATION - Real Esta

SEGMENT INFORMATION - Real Estate Investments, at Cost of Company's Reportable Segments (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Segment Reporting Information [Line Items]
Operating properties	$ 3,472,602	$ 3,474,109	$ 4,006,459
Right of use asset - operating leases, net	20,313	20,977
Construction-in-progress	277,237	210,311
Land held for development	114,604	117,984
Prepaid leasehold interests in land held for development, net	27,762	39,185
Philadelphia CBD
Segment Reporting Information [Line Items]
Operating properties	1,460,510	1,433,927
Pennsylvania Suburbs
Segment Reporting Information [Line Items]
Operating properties	866,223	871,530
Austin, Texas
Segment Reporting Information [Line Items]
Operating properties	778,145	728,741
Metropolitan Washington, D.C.
Segment Reporting Information [Line Items]
Operating properties	280,921	352,794
Other
Segment Reporting Information [Line Items]
Operating properties	$ 86,803	$ 87,117

SEGMENT INFORMATION - Net Opera

SEGMENT INFORMATION - Net Operating Income of Company's Reportable Segments (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Segment Reporting Information [Line Items]
Total revenue	$ 486,819	$ 534,852	$ 580,417
Operating expenses	(188,311)	(205,456)	(225,846)
Net operating income (loss)	298,508	329,396	354,571
Philadelphia CBD
Segment Reporting Information [Line Items]
Total revenue	207,858	232,028	263,769
Pennsylvania Suburbs
Segment Reporting Information [Line Items]
Total revenue	124,566	141,613	141,084
Austin, Texas
Segment Reporting Information [Line Items]
Total revenue	101,680	102,982	104,157
Metropolitan Washington, D.C.
Segment Reporting Information [Line Items]
Total revenue	19,865	40,223	51,498
Operating Segments | Philadelphia CBD
Segment Reporting Information [Line Items]
Total revenue	207,858	232,028	263,769
Operating expenses	(73,695)	(82,505)	(100,219)
Net operating income (loss)	134,163	149,523	163,550
Operating Segments | Pennsylvania Suburbs
Segment Reporting Information [Line Items]
Total revenue	124,566	141,613	141,084
Operating expenses	(40,011)	(46,281)	(47,418)
Net operating income (loss)	84,555	95,332	93,666
Operating Segments | Austin, Texas
Segment Reporting Information [Line Items]
Total revenue	101,680	102,982	104,157
Operating expenses	(39,374)	(39,759)	(38,285)
Net operating income (loss)	62,306	63,223	65,872
Operating Segments | Metropolitan Washington, D.C.
Segment Reporting Information [Line Items]
Total revenue	19,865	40,223	51,498
Operating expenses	(15,386)	(20,791)	(23,455)
Net operating income (loss)	4,479	19,432	28,043
Operating Segments | Other
Segment Reporting Information [Line Items]
Total revenue	14,015	13,469	14,558
Operating expenses	(9,840)	(9,815)	(9,328)
Net operating income (loss)	4,175	3,654	5,230
Corporate
Segment Reporting Information [Line Items]
Total revenue	18,835	4,537	5,351
Operating expenses	(10,005)	(6,305)	(7,141)
Net operating income (loss)	$ 8,830	$ (1,768)	$ (1,790)

SEGMENT INFORMATION - Unconsoli

SEGMENT INFORMATION - Unconsolidated Real Estate Ventures of Company's Reportable Segments (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Segment Reporting Information [Line Items]
Investment in unconsolidated real estate ventures	$ 411,110	$ 389,811
Equity in income (loss) of real estate venture	(26,697)	(18,584)	$ (9,922)
Philadelphia CBD
Segment Reporting Information [Line Items]
Investment in unconsolidated real estate ventures	317,959	268,562
Equity in income (loss) of real estate venture	(15,191)	(9,090)	328
Metropolitan Washington, D.C.
Segment Reporting Information [Line Items]
Investment in unconsolidated real estate ventures	85,867	99,769
Equity in income (loss) of real estate venture	(3,755)	(3,019)	(4,234)
Mid-Atlantic Office Venture
Segment Reporting Information [Line Items]
Investment in unconsolidated real estate ventures	31,680	32,996
Equity in income (loss) of real estate venture	932	96	0
MAP Venture
Segment Reporting Information [Line Items]
Investment in unconsolidated real estate ventures	(24,396)	(11,516)
Equity in income (loss) of real estate venture	(8,683)	(6,571)	(6,102)
Other
Segment Reporting Information [Line Items]
Investment in unconsolidated real estate ventures	0	0
Equity in income (loss) of real estate venture	$ 0	$ 0	$ 86

SEGMENT INFORMATION - Reconcili

SEGMENT INFORMATION - Reconciliation of Consolidated Net Income (Loss) to Consolidated NOI (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Segment Reporting [Abstract]
Net income	$ 12,366	$ 307,326	$ 34,529
Plus:
Interest expense	62,617	73,911	81,512
Interest expense - amortization of deferred financing costs	2,836	2,904	2,768
Depreciation and amortization	178,105	188,283	210,005
General and administrative expenses	30,153	30,288	32,156
Equity in loss of unconsolidated real estate ventures	26,697	18,584	9,922
Less:
Interest and investment income	8,295	1,939	2,318
Income tax (provision) benefit	(47)	224	(12)
Net gain on disposition of real estate	142	289,461	356
Net gain on sale of undepreciated real estate	2,903	201	2,020
Net gain on real estate venture transactions	2,973	75	11,639
Consolidated net operating income	$ 298,508	$ 329,396	$ 354,571

COMMITMENTS AND CONTINGENCIES (

COMMITMENTS AND CONTINGENCIES (Details) $ in Thousands	Oct. 21, 2020USD ($)	Apr. 02, 2015USD ($)	Feb. 28, 2021property	Dec. 31, 2021USD ($)	Jul. 23, 2021USD ($)	Dec. 31, 2020USD ($)	Sep. 30, 2004ft²
Property Subject to or Available for Operating Lease [Line Items]
Real estate ventures aggregate indebtedness				$ 961,509		$ 963,018
Limited payment guarantee, percent of principle balance (up to)					25.00%
Commerce Square | Preferred Equity Investment Obligation
Property Subject to or Available for Operating Lease [Line Items]
Other commitments				20,000
Amount committed to date				2,100
3025 JFK Venture
Property Subject to or Available for Operating Lease [Line Items]
Construction loan amount				186,700	$ 186,700
Natural Disasters and Other Casualty Events
Property Subject to or Available for Operating Lease [Line Items]
Number of properties damaged | property			1
Write-off of fixed assets				1,200
Restoration liability				7,200
Business interruption costs				3,900
Insurance proceeds				15,300
Natural Disasters and Other Casualty Events | Other Income
Property Subject to or Available for Operating Lease [Line Items]
Insurance proceeds				3,000
Natural Disasters and Other Casualty Events | Accounts Payable and Accrued Liabilities
Property Subject to or Available for Operating Lease [Line Items]
Restoration liability				1,900
Unconsolidated Real Estate Ventures
Property Subject to or Available for Operating Lease [Line Items]
Real estate ventures aggregate indebtedness				961,500
Two Logan Square
Property Subject to or Available for Operating Lease [Line Items]
Rentable square feet | ft²							708,844
Settlement liabilities				600
Two Logan Square | Secured Debt
Property Subject to or Available for Operating Lease [Line Items]
Repayments of long-term debt	$ 79,800
618 Market Street
Property Subject to or Available for Operating Lease [Line Items]
Contingent consideration, liability		$ 2,000
Fair value of contingent consideration		1,600
Interest expense		$ 2,000
Schuylkill Yards Project
Property Subject to or Available for Operating Lease [Line Items]
Other commitments				7,000
Estimated potential additional contribution obligation				$ 2,400

Schedule II - Valuation and Q_2

Schedule II - Valuation and Qualifying Accounts (Details) - Allowance for Doubtful Accounts - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Valuation and Qualifying Accounts Disclosure [Line Items]
Balance at Beginning of Year	$ 5,086	$ 7,975	$ 12,919
Additions	0	0	0
Deductions	953	2,889	4,944
Balance at End of Year	$ 4,133	$ 5,086	$ 7,975

Schedule III - Real Estate an_2

Schedule III - Real Estate and Accumulated Depreciation (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Initial Cost
Land	$ 365,011
Buildings and Improvements	2,472,362
Net Improvements (Retirements) Since Acquisition	635,229
Gross Amount Which Carried
Land	410,144
Buildings and Improvements	3,062,458
Total	3,472,602	$ 3,474,109	$ 4,006,459	$ 3,951,719
Accumulated Depreciation at December 31, 2021	957,450	896,561	$ 973,318	$ 885,407
Pennsylvania Suburbs | Six Tower Bridge (181 Washington Street)
Initial Cost
Land		6,927
Buildings and Improvements		14,722
Net Improvements (Retirements) Since Acquisition		1,747
Gross Amount Which Carried
Land		6,237
Buildings and Improvements		17,159
Total		23,396
Accumulated Depreciation at December 31, 2021		4,436
Pennsylvania Suburbs | 426 West Lancaster Avenue
Initial Cost
Land		1,689
Buildings and Improvements		6,756
Net Improvements (Retirements) Since Acquisition		9,400
Gross Amount Which Carried
Land		1,686
Buildings and Improvements		16,159
Total		17,845
Accumulated Depreciation at December 31, 2021		1,614
Pennsylvania Suburbs | 640 Freedom Business Center
Initial Cost
Land		1,015
Buildings and Improvements		20,098
Net Improvements (Retirements) Since Acquisition		4,252
Gross Amount Which Carried
Land		360
Buildings and Improvements		25,005
Total		25,365
Accumulated Depreciation at December 31, 2021		15,445
Pennsylvania Suburbs | 620 Freedom Business Center
Initial Cost
Land		666
Buildings and Improvements		13,118
Net Improvements (Retirements) Since Acquisition		1,498
Gross Amount Which Carried
Land		234
Buildings and Improvements		15,048
Total		15,282
Accumulated Depreciation at December 31, 2021		9,596
Pennsylvania Suburbs | 1000 First Avenue
Initial Cost
Land		0
Buildings and Improvements		13,708
Net Improvements (Retirements) Since Acquisition		2,806
Gross Amount Which Carried
Land		0
Buildings and Improvements		16,514
Total		16,514
Accumulated Depreciation at December 31, 2021		11,778
Pennsylvania Suburbs | 1060 First Avenue
Initial Cost
Land		0
Buildings and Improvements		13,665
Net Improvements (Retirements) Since Acquisition		4,014
Gross Amount Which Carried
Land		0
Buildings and Improvements		17,679
Total		17,679
Accumulated Depreciation at December 31, 2021		12,249
Pennsylvania Suburbs | 630 Freedom Business Center Drive
Initial Cost
Land		666
Buildings and Improvements		13,251
Net Improvements (Retirements) Since Acquisition		2,937
Gross Amount Which Carried
Land		237
Buildings and Improvements		16,617
Total		16,854
Accumulated Depreciation at December 31, 2021		10,322
Pennsylvania Suburbs | 1020 First Avenue
Initial Cost
Land		0
Buildings and Improvements		10,744
Net Improvements (Retirements) Since Acquisition		4,306
Gross Amount Which Carried
Land		0
Buildings and Improvements		15,050
Total		15,050
Accumulated Depreciation at December 31, 2021		10,380
Pennsylvania Suburbs | 1040 First Avenue
Initial Cost
Land		0
Buildings and Improvements		14,142
Net Improvements (Retirements) Since Acquisition		4,915
Gross Amount Which Carried
Land		0
Buildings and Improvements		19,057
Total		19,057
Accumulated Depreciation at December 31, 2021		13,367
Pennsylvania Suburbs | 610 Freedom Business Center Drive
Initial Cost
Land		485
Buildings and Improvements		9,602
Net Improvements (Retirements) Since Acquisition		2,415
Gross Amount Which Carried
Land		172
Buildings and Improvements		12,330
Total		12,502
Accumulated Depreciation at December 31, 2021		8,007
Pennsylvania Suburbs | 650 Park Avenue
Initial Cost
Land		1,916
Buildings and Improvements		4,378
Net Improvements (Retirements) Since Acquisition		(4,378)
Gross Amount Which Carried
Land		1,916
Buildings and Improvements		0
Total		1,916
Accumulated Depreciation at December 31, 2021		0
Pennsylvania Suburbs | 600 Park Avenue
Initial Cost
Land		1,012
Buildings and Improvements		4,048
Net Improvements (Retirements) Since Acquisition		385
Gross Amount Which Carried
Land		1,012
Buildings and Improvements		4,433
Total		5,445
Accumulated Depreciation at December 31, 2021		2,888
Pennsylvania Suburbs | 933 First Avenue
Initial Cost
Land		3,127
Buildings and Improvements		20,794
Net Improvements (Retirements) Since Acquisition		(1,125)
Gross Amount Which Carried
Land		3,127
Buildings and Improvements		19,669
Total		22,796
Accumulated Depreciation at December 31, 2021		3,954
Pennsylvania Suburbs | 500 North Gulph Road
Initial Cost
Land		1,303
Buildings and Improvements		5,201
Net Improvements (Retirements) Since Acquisition		21,471
Gross Amount Which Carried
Land		1,303
Buildings and Improvements		26,672
Total		27,975
Accumulated Depreciation at December 31, 2021		3,526
Pennsylvania Suburbs | 401 Plymouth Road
Initial Cost
Land		6,199
Buildings and Improvements		16,131
Net Improvements (Retirements) Since Acquisition		15,622
Gross Amount Which Carried
Land		6,199
Buildings and Improvements		31,753
Total		37,952
Accumulated Depreciation at December 31, 2021		16,559
Pennsylvania Suburbs | Metroplex (4000 Chemical Road)
Initial Cost
Land		4,373
Buildings and Improvements		24,546
Net Improvements (Retirements) Since Acquisition		5,498
Gross Amount Which Carried
Land		4,373
Buildings and Improvements		30,044
Total		34,417
Accumulated Depreciation at December 31, 2021		8,667
Pennsylvania Suburbs | 610 West Germantown Pike
Initial Cost
Land		3,651
Buildings and Improvements		14,514
Net Improvements (Retirements) Since Acquisition		4,493
Gross Amount Which Carried
Land		3,651
Buildings and Improvements		19,007
Total		22,658
Accumulated Depreciation at December 31, 2021		9,635
Pennsylvania Suburbs | 600 West Germantown Pike
Initial Cost
Land		3,652
Buildings and Improvements		15,288
Net Improvements (Retirements) Since Acquisition		2,692
Gross Amount Which Carried
Land		3,652
Buildings and Improvements		17,980
Total		21,632
Accumulated Depreciation at December 31, 2021		8,989
Pennsylvania Suburbs | 630 West Germantown Pike
Initial Cost
Land		3,558
Buildings and Improvements		14,743
Net Improvements (Retirements) Since Acquisition		2,221
Gross Amount Which Carried
Land		3,558
Buildings and Improvements		16,964
Total		20,522
Accumulated Depreciation at December 31, 2021		8,623
Pennsylvania Suburbs | 620 West Germantown Pike
Initial Cost
Land		3,572
Buildings and Improvements		14,435
Net Improvements (Retirements) Since Acquisition		2,541
Gross Amount Which Carried
Land		3,572
Buildings and Improvements		16,976
Total		20,548
Accumulated Depreciation at December 31, 2021		7,992
Pennsylvania Suburbs | 660 West Germantown Pike
Initial Cost
Land		3,694
Buildings and Improvements		5,487
Net Improvements (Retirements) Since Acquisition		19,473
Gross Amount Which Carried
Land		5,405
Buildings and Improvements		23,249
Total		28,654
Accumulated Depreciation at December 31, 2021		7,549
Pennsylvania Suburbs | 351 Plymouth Road
Initial Cost
Land		1,043
Buildings and Improvements		555
Net Improvements (Retirements) Since Acquisition		0
Gross Amount Which Carried
Land		1,043
Buildings and Improvements		555
Total		1,598
Accumulated Depreciation at December 31, 2021		232
Pennsylvania Suburbs | 150 Radnor Chester Road
Initial Cost
Land		11,925
Buildings and Improvements		36,986
Net Improvements (Retirements) Since Acquisition		21,940
Gross Amount Which Carried
Land		11,897
Buildings and Improvements		58,954
Total		70,851
Accumulated Depreciation at December 31, 2021		23,715
Pennsylvania Suburbs | One Radnor Corporate Center
Initial Cost
Land		7,323
Buildings and Improvements		28,613
Net Improvements (Retirements) Since Acquisition		18,811
Gross Amount Which Carried
Land		7,323
Buildings and Improvements		47,424
Total		54,747
Accumulated Depreciation at December 31, 2021		33,343
Pennsylvania Suburbs | 201 King of Prussia Road
Initial Cost
Land		8,956
Buildings and Improvements		29,811
Net Improvements (Retirements) Since Acquisition		4,816
Gross Amount Which Carried
Land		8,949
Buildings and Improvements		34,634
Total		43,583
Accumulated Depreciation at December 31, 2021		22,224
Pennsylvania Suburbs | 555 Lancaster Avenue
Initial Cost
Land		8,014
Buildings and Improvements		16,508
Net Improvements (Retirements) Since Acquisition		10,137
Gross Amount Which Carried
Land		8,609
Buildings and Improvements		26,050
Total		34,659
Accumulated Depreciation at December 31, 2021		11,546
Pennsylvania Suburbs | Four Radnor Corporate Center
Initial Cost
Land		5,406
Buildings and Improvements		21,390
Net Improvements (Retirements) Since Acquisition		11,094
Gross Amount Which Carried
Land		5,705
Buildings and Improvements		32,185
Total		37,890
Accumulated Depreciation at December 31, 2021		17,219
Pennsylvania Suburbs | Five Radnor Corporate Center
Initial Cost
Land		6,506
Buildings and Improvements		25,525
Net Improvements (Retirements) Since Acquisition		8,682
Gross Amount Which Carried
Land		6,578
Buildings and Improvements		34,135
Total		40,713
Accumulated Depreciation at December 31, 2021		15,124
Pennsylvania Suburbs | Three Radnor Corporate Center
Initial Cost
Land		4,773
Buildings and Improvements		17,961
Net Improvements (Retirements) Since Acquisition		2,016
Gross Amount Which Carried
Land		4,791
Buildings and Improvements		19,959
Total		24,750
Accumulated Depreciation at December 31, 2021		11,401
Pennsylvania Suburbs | Two Radnor Corporate Center
Initial Cost
Land		3,937
Buildings and Improvements		15,484
Net Improvements (Retirements) Since Acquisition		2,685
Gross Amount Which Carried
Land		3,942
Buildings and Improvements		18,164
Total		22,106
Accumulated Depreciation at December 31, 2021		11,120
Pennsylvania Suburbs | 130 Radnor Chester Road
Initial Cost
Land		2,573
Buildings and Improvements		8,338
Net Improvements (Retirements) Since Acquisition		(134)
Gross Amount Which Carried
Land		2,567
Buildings and Improvements		8,210
Total		10,777
Accumulated Depreciation at December 31, 2021		3,997
Pennsylvania Suburbs | 170 Radnor Chester Road
Initial Cost
Land		2,514
Buildings and Improvements		8,147
Net Improvements (Retirements) Since Acquisition		1,667
Gross Amount Which Carried
Land		2,509
Buildings and Improvements		9,819
Total		12,328
Accumulated Depreciation at December 31, 2021		5,138
Pennsylvania Suburbs | 200 Radnor Chester Road
Initial Cost
Land		3,366
Buildings and Improvements		0
Net Improvements (Retirements) Since Acquisition		3,621
Gross Amount Which Carried
Land		3,366
Buildings and Improvements		3,621
Total		6,987
Accumulated Depreciation at December 31, 2021		995
Pennsylvania Suburbs | 101 West Elm Street
Initial Cost
Land		6,251
Buildings and Improvements		25,209
Net Improvements (Retirements) Since Acquisition		3,057
Gross Amount Which Carried
Land		6,251
Buildings and Improvements		28,266
Total		34,517
Accumulated Depreciation at December 31, 2021		11,729
Pennsylvania Suburbs | 1 West Elm Street
Initial Cost
Land		3,557
Buildings and Improvements		14,249
Net Improvements (Retirements) Since Acquisition		7,712
Gross Amount Which Carried
Land		3,557
Buildings and Improvements		21,961
Total		25,518
Accumulated Depreciation at December 31, 2021		6,723
Pennsylvania Suburbs | Four Tower Bridge (200 Barr Harbor Drive)
Initial Cost
Land		6,000
Buildings and Improvements		14,734
Net Improvements (Retirements) Since Acquisition		402
Gross Amount Which Carried
Land		6,000
Buildings and Improvements		15,136
Total		21,136
Accumulated Depreciation at December 31, 2021		$ 1,650
Philadelphia CBD | Cira Centre (2929 Arch Street)
Initial Cost
Land	0
Buildings and Improvements	208,570
Net Improvements (Retirements) Since Acquisition	(22,427)
Gross Amount Which Carried
Land	12,586
Buildings and Improvements	173,557
Total	186,143
Accumulated Depreciation at December 31, 2021	67,765
Philadelphia CBD | Three Logan Square (1717 Arch Street)
Initial Cost
Land	0
Buildings and Improvements	98,188
Net Improvements (Retirements) Since Acquisition	84,992
Gross Amount Which Carried
Land	25,195
Buildings and Improvements	157,985
Total	183,180
Accumulated Depreciation at December 31, 2021	54,136
Philadelphia CBD | One Logan Square (130 North 18th Street)
Initial Cost
Land	14,496
Buildings and Improvements	107,736
Net Improvements (Retirements) Since Acquisition	21,633
Gross Amount Which Carried
Land	14,473
Buildings and Improvements	129,392
Total	143,865
Accumulated Depreciation at December 31, 2021	65,373
Philadelphia CBD | Two Logan Square (100 North 18th Street)
Initial Cost
Land	16,066
Buildings and Improvements	100,255
Net Improvements (Retirements) Since Acquisition	26,795
Gross Amount Which Carried
Land	16,066
Buildings and Improvements	127,050
Total	143,116
Accumulated Depreciation at December 31, 2021	56,054
Philadelphia CBD | Cira Centre South Garage (129 South 30th Street)
Initial Cost
Land	0
Buildings and Improvements	76,008
Net Improvements (Retirements) Since Acquisition	26,885
Gross Amount Which Carried
Land	6,727
Buildings and Improvements	96,166
Total	102,893
Accumulated Depreciation at December 31, 2021	25,080
Philadelphia CBD | 1900 Market Street
Initial Cost
Land	7,768
Buildings and Improvements	17,263
Net Improvements (Retirements) Since Acquisition	61,783
Gross Amount Which Carried
Land	7,768
Buildings and Improvements	79,046
Total	86,814
Accumulated Depreciation at December 31, 2021	25,142
Philadelphia CBD | 3020 Market Street
Initial Cost
Land	0
Buildings and Improvements	21,417
Net Improvements (Retirements) Since Acquisition	7,751
Gross Amount Which Carried
Land	0
Buildings and Improvements	29,168
Total	29,168
Accumulated Depreciation at December 31, 2021	12,800
Philadelphia CBD | 618-634 Market Street
Initial Cost
Land	13,365
Buildings and Improvements	5,791
Net Improvements (Retirements) Since Acquisition	5,186
Gross Amount Which Carried
Land	13,365
Buildings and Improvements	10,977
Total	24,342
Accumulated Depreciation at December 31, 2021	6,821
Philadelphia CBD | FMC Tower at Cira Centre South (2929 Walnut Street)
Initial Cost
Land	0
Buildings and Improvements	400,294
Net Improvements (Retirements) Since Acquisition	9,493
Gross Amount Which Carried
Land	0
Buildings and Improvements	409,787
Total	409,787
Accumulated Depreciation at December 31, 2021	70,803
Philadelphia CBD | 2100 Market Street
Initial Cost
Land	18,827
Buildings and Improvements	0
Net Improvements (Retirements) Since Acquisition	6,300
Gross Amount Which Carried
Land	18,854
Buildings and Improvements	6,273
Total	25,127
Accumulated Depreciation at December 31, 2021	1,858
Philadelphia CBD | 1505-11 Race Street
Initial Cost
Land	3,662
Buildings and Improvements	6,061
Net Improvements (Retirements) Since Acquisition	8
Gross Amount Which Carried
Land	3,670
Buildings and Improvements	6,061
Total	9,731
Accumulated Depreciation at December 31, 2021	177
Philadelphia CBD | 3000 Market Street
Initial Cost
Land	18,924
Buildings and Improvements	13,080
Net Improvements (Retirements) Since Acquisition	16,264
Gross Amount Which Carried
Land	18,924
Buildings and Improvements	29,344
Total	48,268
Accumulated Depreciation at December 31, 2021	504
Philadelphia CBD | The Bulletin Building (3025 Market Street)
Initial Cost
Land	0
Buildings and Improvements	24,377
Net Improvements (Retirements) Since Acquisition	43,599
Gross Amount Which Carried
Land	0
Buildings and Improvements	67,976
Total	67,976
Accumulated Depreciation at December 31, 2021	7,928
Philadelphia CBD | 3001-3003 JFK Boulevard
Initial Cost
Land	0
Buildings and Improvements	0
Net Improvements (Retirements) Since Acquisition	111
Gross Amount Which Carried
Land	0
Buildings and Improvements	111
Total	111
Accumulated Depreciation at December 31, 2021	24
Metropolitan Washington, D.C. | 6600 Rockledge Drive
Initial Cost
Land	0
Buildings and Improvements	37,421
Net Improvements (Retirements) Since Acquisition	9,956
Gross Amount Which Carried
Land	0
Buildings and Improvements	47,377
Total	47,377
Accumulated Depreciation at December 31, 2021	17,816
Metropolitan Washington, D.C. | 1676 International Drive
Initial Cost
Land	18,437
Buildings and Improvements	97,538
Net Improvements (Retirements) Since Acquisition	25,740
Gross Amount Which Carried
Land	18,785
Buildings and Improvements	122,930
Total	141,715
Accumulated Depreciation at December 31, 2021	31,083
Metropolitan Washington, D.C. | 8260 Greensboro Drive
Initial Cost
Land	7,952
Buildings and Improvements	33,964
Net Improvements (Retirements) Since Acquisition	8,114
Gross Amount Which Carried
Land	8,102
Buildings and Improvements	41,928
Total	50,030
Accumulated Depreciation at December 31, 2021	13,598
Metropolitan Washington, D.C. | 8521 Leesburg Pike
Initial Cost
Land	4,316
Buildings and Improvements	30,885
Net Improvements (Retirements) Since Acquisition	6,575
Gross Amount Which Carried
Land	4,397
Buildings and Improvements	37,379
Total	41,776
Accumulated Depreciation at December 31, 2021	14,332
Austin, Texas | 401-405 Colorado Street
Initial Cost
Land	0
Buildings and Improvements	47,132
Net Improvements (Retirements) Since Acquisition	0
Gross Amount Which Carried
Land	0
Buildings and Improvements	47,132
Total	47,132
Accumulated Depreciation at December 31, 2021	491
Austin, Texas | 11501 Burnet Road - Building 1
Initial Cost
Land	3,755
Buildings and Improvements	22,702
Net Improvements (Retirements) Since Acquisition	4
Gross Amount Which Carried
Land	3,755
Buildings and Improvements	22,706
Total	26,461
Accumulated Depreciation at December 31, 2021	6,062
Austin, Texas | 11501 Burnet Road - Building 2
Initial Cost
Land	2,732
Buildings and Improvements	16,305
Net Improvements (Retirements) Since Acquisition	1,473
Gross Amount Which Carried
Land	2,732
Buildings and Improvements	17,778
Total	20,510
Accumulated Depreciation at December 31, 2021	5,252
Austin, Texas | 11501 Burnet Road - Building 3
Initial Cost
Land	3,688
Buildings and Improvements	22,348
Net Improvements (Retirements) Since Acquisition	(1,510)
Gross Amount Which Carried
Land	3,688
Buildings and Improvements	20,838
Total	24,526
Accumulated Depreciation at December 31, 2021	5,560
Austin, Texas | 11501 Burnet Road - Building 4
Initial Cost
Land	2,614
Buildings and Improvements	15,740
Net Improvements (Retirements) Since Acquisition	3
Gross Amount Which Carried
Land	2,614
Buildings and Improvements	15,743
Total	18,357
Accumulated Depreciation at December 31, 2021	4,203
Austin, Texas | 11501 Burnet Road - Building 5
Initial Cost
Land	3,689
Buildings and Improvements	22,354
Net Improvements (Retirements) Since Acquisition	4
Gross Amount Which Carried
Land	3,689
Buildings and Improvements	22,358
Total	26,047
Accumulated Depreciation at December 31, 2021	5,970
Austin, Texas | 11501 Burnet Road - Building 6
Initial Cost
Land	2,676
Buildings and Improvements	15,972
Net Improvements (Retirements) Since Acquisition	13,964
Gross Amount Which Carried
Land	2,676
Buildings and Improvements	29,936
Total	32,612
Accumulated Depreciation at December 31, 2021	8,808
Austin, Texas | 11501 Burnet Road - Building 8
Initial Cost
Land	1,400
Buildings and Improvements	7,422
Net Improvements (Retirements) Since Acquisition	1,521
Gross Amount Which Carried
Land	1,400
Buildings and Improvements	8,943
Total	10,343
Accumulated Depreciation at December 31, 2021	2,452
Austin, Texas | 11501 Burnet Road - Parking Garage
Initial Cost
Land	0
Buildings and Improvements	19,826
Net Improvements (Retirements) Since Acquisition	3
Gross Amount Which Carried
Land	0
Buildings and Improvements	19,829
Total	19,829
Accumulated Depreciation at December 31, 2021	6,289
Austin, Texas | Four Points Centre 3, 11120 Four Points Drive
Initial Cost
Land	1,140
Buildings and Improvements	0
Net Improvements (Retirements) Since Acquisition	40,322
Gross Amount Which Carried
Land	1,141
Buildings and Improvements	40,321
Total	41,462
Accumulated Depreciation at December 31, 2021	5,062
Austin, Texas | One Barton Skyway (1501 South MoPac Expressway)
Initial Cost
Land	10,496
Buildings and Improvements	47,670
Net Improvements (Retirements) Since Acquisition	5,421
Gross Amount Which Carried
Land	10,495
Buildings and Improvements	53,092
Total	63,587
Accumulated Depreciation at December 31, 2021	4,697
Austin, Texas | Two Barton Skyway (1601 South MoPac Expressway)
Initial Cost
Land	10,849
Buildings and Improvements	53,868
Net Improvements (Retirements) Since Acquisition	3,454
Gross Amount Which Carried
Land	10,848
Buildings and Improvements	57,323
Total	68,171
Accumulated Depreciation at December 31, 2021	5,390
Austin, Texas | Three Barton Skyway (1221 South MoPac Expressway)
Initial Cost
Land	10,374
Buildings and Improvements	47,624
Net Improvements (Retirements) Since Acquisition	286
Gross Amount Which Carried
Land	10,373
Buildings and Improvements	47,911
Total	58,284
Accumulated Depreciation at December 31, 2021	3,865
Austin, Texas | Four Barton Skyway (1301 South MoPac Expressway)
Initial Cost
Land	13,301
Buildings and Improvements	57,041
Net Improvements (Retirements) Since Acquisition	4,060
Gross Amount Which Carried
Land	13,300
Buildings and Improvements	61,102
Total	74,402
Accumulated Depreciation at December 31, 2021	5,044
Austin, Texas | Four Points Centre (11305 Four Points Drive)
Initial Cost
Land	7,800
Buildings and Improvements	43,581
Net Improvements (Retirements) Since Acquisition	3,981
Gross Amount Which Carried
Land	7,800
Buildings and Improvements	47,562
Total	55,362
Accumulated Depreciation at December 31, 2021	4,640
Austin, Texas | River Place - Building 1 (6500 River Place Boulevard)
Initial Cost
Land	2,004
Buildings and Improvements	17,680
Net Improvements (Retirements) Since Acquisition	547
Gross Amount Which Carried
Land	2,004
Buildings and Improvements	18,227
Total	20,231
Accumulated Depreciation at December 31, 2021	1,624
Austin, Texas | River Place - Building 2 (6500 River Place Boulevard)
Initial Cost
Land	3,137
Buildings and Improvements	29,254
Net Improvements (Retirements) Since Acquisition	675
Gross Amount Which Carried
Land	3,137
Buildings and Improvements	29,929
Total	33,066
Accumulated Depreciation at December 31, 2021	2,490
Austin, Texas | River Place - Building 3 (6500 River Place Boulevard)
Initial Cost
Land	3,064
Buildings and Improvements	26,705
Net Improvements (Retirements) Since Acquisition	294
Gross Amount Which Carried
Land	3,064
Buildings and Improvements	26,999
Total	30,063
Accumulated Depreciation at December 31, 2021	2,164
Austin, Texas | River Place - Building 4 (6500 River Place Boulevard
Initial Cost
Land	2,273
Buildings and Improvements	18,617
Net Improvements (Retirements) Since Acquisition	1,141
Gross Amount Which Carried
Land	2,273
Buildings and Improvements	19,758
Total	22,031
Accumulated Depreciation at December 31, 2021	2,030
Austin, Texas | River Place - Building 5 (6500 River Place Boulevard)
Initial Cost
Land	1,752
Buildings and Improvements	14,315
Net Improvements (Retirements) Since Acquisition	106
Gross Amount Which Carried
Land	1,752
Buildings and Improvements	14,421
Total	16,173
Accumulated Depreciation at December 31, 2021	1,161
Austin, Texas | River Place - Building 6 (6500 River Place Boulevard)
Initial Cost
Land	1,598
Buildings and Improvements	12,945
Net Improvements (Retirements) Since Acquisition	30
Gross Amount Which Carried
Land	1,598
Buildings and Improvements	12,975
Total	14,573
Accumulated Depreciation at December 31, 2021	1,027
Austin, Texas | River Place - Building 7 (6500 River Place Boulevard)
Initial Cost
Land	1,801
Buildings and Improvements	16,486
Net Improvements (Retirements) Since Acquisition	1,103
Gross Amount Which Carried
Land	1,801
Buildings and Improvements	17,589
Total	19,390
Accumulated Depreciation at December 31, 2021	1,837
Austin, Texas | Quarry Lake II (4516 Seton Center Parkway)
Initial Cost
Land	3,970
Buildings and Improvements	30,546
Net Improvements (Retirements) Since Acquisition	1,024
Gross Amount Which Carried
Land	3,867
Buildings and Improvements	31,673
Total	35,540
Accumulated Depreciation at December 31, 2021	2,681
Other | 10 Foster Avenue
Initial Cost
Land	244
Buildings and Improvements	971
Net Improvements (Retirements) Since Acquisition	110
Gross Amount Which Carried
Land	244
Buildings and Improvements	1,081
Total	1,325
Accumulated Depreciation at December 31, 2021	666
Other | 7 Foster Avenue
Initial Cost
Land	231
Buildings and Improvements	921
Net Improvements (Retirements) Since Acquisition	31
Gross Amount Which Carried
Land	231
Buildings and Improvements	952
Total	1,183
Accumulated Depreciation at December 31, 2021	601
Other | 2 Foster Avenue
Initial Cost
Land	185
Buildings and Improvements	730
Net Improvements (Retirements) Since Acquisition	11
Gross Amount Which Carried
Land	185
Buildings and Improvements	741
Total	926
Accumulated Depreciation at December 31, 2021	741
Other | 4 Foster Avenue
Initial Cost
Land	183
Buildings and Improvements	726
Net Improvements (Retirements) Since Acquisition	6
Gross Amount Which Carried
Land	183
Buildings and Improvements	732
Total	915
Accumulated Depreciation at December 31, 2021	732
Other | 1 Foster Avenue
Initial Cost
Land	93
Buildings and Improvements	364
Net Improvements (Retirements) Since Acquisition	8
Gross Amount Which Carried
Land	93
Buildings and Improvements	372
Total	465
Accumulated Depreciation at December 31, 2021	372
Other | 5 U.S. Avenue
Initial Cost
Land	21
Buildings and Improvements	81
Net Improvements (Retirements) Since Acquisition	2
Gross Amount Which Carried
Land	21
Buildings and Improvements	83
Total	104
Accumulated Depreciation at December 31, 2021	83
Other | 5 Foster Avenue
Initial Cost
Land	9
Buildings and Improvements	32
Net Improvements (Retirements) Since Acquisition	3
Gross Amount Which Carried
Land	9
Buildings and Improvements	35
Total	44
Accumulated Depreciation at December 31, 2021	35
Other | Main Street-Plaza 1000
Initial Cost
Land	2,732
Buildings and Improvements	10,942
Net Improvements (Retirements) Since Acquisition	284
Gross Amount Which Carried
Land	2,732
Buildings and Improvements	11,226
Total	13,958
Accumulated Depreciation at December 31, 2021	11,036
Other | Main Street-Piazza
Initial Cost
Land	696
Buildings and Improvements	2,802
Net Improvements (Retirements) Since Acquisition	3,631
Gross Amount Which Carried
Land	704
Buildings and Improvements	6,425
Total	7,129
Accumulated Depreciation at December 31, 2021	4,214
Other | Main Street-Promenade
Initial Cost
Land	532
Buildings and Improvements	2,052
Net Improvements (Retirements) Since Acquisition	285
Gross Amount Which Carried
Land	532
Buildings and Improvements	2,337
Total	2,869
Accumulated Depreciation at December 31, 2021	1,476
Other | 920 North King Street
Initial Cost
Land	6,141
Buildings and Improvements	21,140
Net Improvements (Retirements) Since Acquisition	8,037
Gross Amount Which Carried
Land	6,141
Buildings and Improvements	29,177
Total	35,318
Accumulated Depreciation at December 31, 2021	15,938
Other | 300 Delaware Avenue
Initial Cost
Land	6,369
Buildings and Improvements	13,739
Net Improvements (Retirements) Since Acquisition	2,468
Gross Amount Which Carried
Land	6,369
Buildings and Improvements	16,207
Total	22,576
Accumulated Depreciation at December 31, 2021	$ 9,731

Schedule III - Real Estate an_3

Schedule III - Real Estate and Accumulated Depreciation (Reconciliations) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Balance at the Beginning of the Year	$ 3,474,109	$ 4,006,459	$ 3,951,719
Additions:
Acquisitions	0	9,722	0
Capital expenditures and assets placed into service	134,931	113,221	145,378
Less:
Dispositions/impairments/placed into redevelopment	(82,247)	(619,086)	(50,792)
Retirements	(54,191)	(36,207)	(39,846)
Balance at the end of the year	3,472,602	3,474,109	4,006,459
Operating properties	3,472,602	3,474,109	4,006,459
Tax basis of assets, cost for income tax purposes	3,100,000	2,900,000
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Balance at the beginning of the year	896,561	973,318	885,407
Additions:
Depreciation expense	136,171	138,822	144,131
Less:
Dispositions/impairments/placed into redevelopment	(24,440)	(182,526)	(16,783)
Retirements	(50,842)	(33,053)	(39,437)
Balance at the end of the year	957,450	896,561	973,318
Per consolidated balance sheet	957,450	896,561	$ 973,318
BRANDYWINE OPERATING PARTNERSHIP, L.P.
Less:
Operating properties	3,472,602	3,474,109
Tax basis of assets, cost for income tax purposes	3,100,000	2,900,000
Less:
Per consolidated balance sheet	$ 957,450	$ 896,561
Leashold Interest Land
Less:
Lease agreement term	99 years
Maximum
Less:
Useful life	55 years