Consolidated Statements of Cash Flows (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Cash flows from operating activities:
Net income (loss)	$ 6,942	$ 43,189	$ 6,529
Adjustments to reconcile net income (loss) to net cash from operating activities:
Depreciation and amortization	208,569	198,731	198,579
Amortization of deferred financing costs	5,148	4,676	6,208
Amortization of debt discount/(premium), net	(531)	2,480	1,760
Amortization of stock compensation costs	4,137	6,998	5,685
Shares used for employee taxes upon vesting of share awards	(1,177)	(1,062)	(2,493)
Recognized hedge activity	828	0	2,985
Straight-line rent income	(16,046)	(20,136)	(23,566)
Amortization of above (below) Market Leases, Net	(6,377)	(7,170)	(6,084)
Straight-line ground rent expense	89	1,509	1,897
Provision for doubtful accounts	1,763	2,467	2,198
Net gain on sale of interests in real estate	(6,085)	(29,166)	(34,774)
Loss on real estate venture formation	0	0	950
Net gain on real estate venture transactions	417	(3,683)	0
Net gain from remeasurement of investments in real estate ventures	(458)	(6,866)	0
Loss on early extinguishment of debt	7,594	2,119	22,002
Provision for impairment on assets held for sale	1,765	0	0
Historic tax credit transaction income	(11,853)	(11,853)	(11,840)
Real estate venture income in excess of distributions	1,954	(2,014)	(1,517)
Deferred financing obligation	(1,147)	(974)	(1,803)
Changes in assets and liabilities:
Accounts receivable	(2,869)	(4,048)	262
Other assets	(4,111)	5,440	4,244
Accounts payable and accrued expenses	962	(526)	(8,355)
Deferred income, gains and rent	2,436	3,758	(2,167)
Other liabilities	(2,951)	(385)	(1,590)
Net cash from operating activities	188,999	183,484	159,110
Cash flows from investing activities:
Acquisition of properties	(18,443)	(161,604)	(77,555)
Investments in available-for-sale securities	0	0	(105,250)
Proceeds from the sale of available-for-sale securities	0	0	105,250
Sales of properties, net	118,855	423,480	170,918
Net proceeds from the contribution of land to an unconsolidated real estate venture	8,212	0	0
Distribution of sales proceeds of real estate ventures	0	16,963	0
Proceeds from repayment of mortgage notes receivable	7,026	200	23,364
Capital expenditures for tenant improvements	(131,077)	(109,357)	(86,986)
Capital expenditures for redevelopments	(19,245)	(6,265)	(11,964)
Capital expenditures for developments	(86,608)	(5,490)	(162)
Reimbursement from real estate venture pre-formation development costs	0	1,976	0
Advances for purchase of tenant assets, net of repayments	(540)	(127)	270
Loan proceeds from an unconsolidated real estate venture	0	0	566
Loan provided to unconsolidated real estate venture	(88,000)	0	0
Investment in unconsolidated real estate venture	(46,098)	(33,069)	(65,354)
Increase (Decrease) in escrow cash	283	1,902	(1,827)
Cash distributions from unconsolidated Real Estate Ventures in excess of cumulative equity income	9,767	7,496	5,109
Leasing costs	(24,917)	(31,397)	(31,243)
Net cash from (used in) investing activities	(270,785)	104,708	(74,864)
Cash flows from financing activities:
Proceeds from unsecured term loans	0	0	600,000
Proceeds from Credit Facility borrowings	0	186,000	90,500
Repayments of Credit Facility borrowings	0	(255,000)	(297,000)
Repayments of mortgage notes payable	(13,441)	(11,268)	(68,513)
Proceeds from unsecured notes	496,459	0	248,183
Deferred financing obligation interest expense	0	0	935
Net proceeds from issuance of common stock	335,016	181,527	0
Net proceeds from issuance of preferred shares	0	0	96,237
Redemption of preferred units	0	0	(108,536)
Redemption of partnership units	0	0	(9,676)
Redemption of unsecured notes	(383,768)	(31,369)	(338,097)
Repayments of unsecured term loan	(250,828)	0	(190,485)
Debt financing costs	(3,705)	(355)	(10,128)
Exercise of stock options	2,143	2,381	976
Distributions paid to shareholders/unitholders	(104,731)	(97,367)	(96,030)
Distributions to noncontrolling interest	(1,064)	(1,083)	(1,473)
Net cash from (used in) financing activities	76,081	(26,534)	(83,107)
Increase (decrease) in cash and cash equivalents	(5,705)	261,658	1,139
Cash and cash equivalents at beginning of period	263,207	1,549	410
Cash and cash equivalents at end of period	257,502	263,207	1,549
Supplemental disclosure:
Cash paid for interest, net of capitalized interest during the years ended December 31, 2014, 2013, and 2012 of $6,802, $3,137 and $2,560, respectively	129,160	118,714	137,823
Supplemental disclosure of non-cash activity:
Change in operating real estate related to a non-cash acquisition of an operating property			0
Change in operating real estate related to a non-cash acquisition of an operating property	0	(21,649)
Change in intangible assets, net related to non-cash acquisition of an operating property	0	(3,517)	0
Change in acquired lease intangibles, net related to non-cash acquisition of an operating property	0	462	0
Change in investments in joint venture related to non-cash acquisition of property	0	13,040	0
Change in investments in joint venture related to non-cash disposition of property	(5,897)	(17,628)	0
Change in operating real estate related to non-cash adjustment to land	0	7,752	0
Change in receivable from settlement of acquisitions	619	0	0
Change in mortgage notes payable related to acquisition of an operating property	0	238,082	0
Change in investments in joint venture related to a contribution of land at period end	(1,182)	(6,058)	(15,222)
Change in investments in joint venture related to a contribution of services	0	0	(711)
Change in capital expenditures financed through accounts payable at period end	7,336	11,703	7,059
Change in capital expenditures financed through retention payable at period end	6,164	(204)	566
Change in unfunded tenant allowance	(955)	(969)	(1,089)
BRANDYWINE OPERATING PARTNERSHIP, L.P.
Cash flows from operating activities:
Net income (loss)	6,942	43,189	6,529
Adjustments to reconcile net income (loss) to net cash from operating activities:
Depreciation and amortization	208,569	198,731	198,579
Amortization of deferred financing costs	5,148	4,676	6,208
Amortization of debt discount/(premium), net	(531)	2,480	1,760
Amortization of stock compensation costs	4,137	6,998	5,685
Shares used for employee taxes upon vesting of share awards	(1,177)	(1,062)	(2,493)
Recognized hedge activity	828	0	2,985
Straight-line rent income	(16,046)	(20,136)	(23,566)
Amortization of above (below) Market Leases, Net	(6,377)	(7,170)	(6,084)
Straight-line ground rent expense	89	1,509	1,897
Provision for doubtful accounts	1,763	2,467	2,198
Net gain on sale of interests in real estate	(6,085)	(29,166)	(34,774)
Loss on real estate venture formation	0	0	950
Net gain from remeasurement of investments in real estate ventures	(458)	(6,866)	0
Net gain (loss) on real estate venture transactions	417	(3,683)	0
Loss on early extinguishment of debt	7,594	2,119	22,002
Provision for impairment on assets held for sale	1,765	0	0
Historic tax credit transaction income	(11,853)	(11,853)	(11,840)
Real estate venture income in excess of distributions	1,954	(2,014)	(1,517)
Cumulative interest accretion of repayments of unsecured notes	0	0	0
Contributions from historic tax credit transaction, net of deferred costs	0	0	0
Deferred financing obligation	(1,147)	(974)	(1,803)
Changes in assets and liabilities:
Accounts receivable	(2,869)	(4,048)	262
Other assets	(4,111)	5,440	4,244
Accounts payable and accrued expenses	962	(526)	(8,355)
Deferred income, gains and rent	2,436	3,758	(2,167)
Other liabilities	(2,951)	(385)	(1,590)
Net cash from operating activities	188,999	183,484	159,110
Cash flows from investing activities:
Acquisition of properties	(18,443)	(161,604)	(77,555)
Investments in available-for-sale securities	0	0	(105,250)
Proceeds from the sale of available-for-sale securities	0	0	105,250
Sales of properties, net	118,855	423,480	170,918
Net proceeds from the contribution of land to an unconsolidated real estate venture	8,212	0	0
Distribution of sales proceeds of real estate ventures	0	16,963
Proceeds from repayment of mortgage notes receivable	7,026	200	23,364
Capital expenditures for tenant improvements	(131,077)	(109,357)	(86,986)
Capital expenditures for redevelopments	(19,245)	(6,265)	(11,964)
Capital expenditures for developments	(86,608)	(5,490)	(162)
Reimbursement from real estate venture pre-formation development costs	0	1,976
Advances for purchase of tenant assets, net of repayments	(540)	(127)	270
Loan proceeds from an unconsolidated real estate venture	0	0	566
Loan provided to unconsolidated real estate venture	(88,000)	0	0
Investment in unconsolidated real estate venture	(46,098)	(33,069)	(65,354)
Increase (Decrease) in escrow cash	283	1,902	(1,827)
Cash distributions from unconsolidated Real Estate Ventures in excess of cumulative equity income	9,767	7,496	5,109
Leasing costs	(24,917)	(31,397)	(31,243)
Net cash from (used in) investing activities	(270,785)	104,708	(74,864)
Cash flows from financing activities:
Proceeds from unsecured term loans	0	0	600,000
Proceeds from Credit Facility borrowings	0	186,000	90,500
Repayments of Credit Facility borrowings	0	(255,000)	(297,000)
Repayments of mortgage notes payable	(13,441)	(11,268)	(68,513)
Proceeds from unsecured notes	496,459	0	248,183
Deferred financing obligation interest expense	0	0	935
Net proceeds from issuance of common stock	335,016	181,527	0
Net proceeds from issuance of preferred shares	0	0	96,237
Redemption of preferred units	0	0	(108,536)
Redemption of partnership units	0	0	(9,676)
Redemption of unsecured notes	(383,768)	(31,369)	(338,097)
Repayments of unsecured term loan	(250,828)	0	(190,485)
Debt financing costs	(3,705)	(355)	(10,128)
Exercise of stock options	2,143	2,381	976
Distributions paid to shareholders/unitholders	(105,795)	(98,450)	(97,503)
Net cash from (used in) financing activities	76,081	(26,534)	(83,107)
Increase (decrease) in cash and cash equivalents	(5,705)	261,658	1,139
Cash and cash equivalents at beginning of period	263,207	1,549	410
Cash and cash equivalents at end of period	257,502	263,207	1,549
Supplemental disclosure:
Cash paid for interest, net of capitalized interest during the years ended December 31, 2014, 2013, and 2012 of $6,802, $3,137 and $2,560, respectively	129,160	118,714	137,823
Supplemental disclosure of non-cash activity:
Change in operating real estate related to a non-cash acquisition of an operating property	0	(21,649)	0
Change in intangible assets, net related to non-cash acquisition of an operating property	0	(3,517)
Change in acquired lease intangibles, net related to non-cash acquisition of an operating property	0	462
Change in investments in joint venture related to non-cash acquisition of property	0	13,040
Change in investments in joint venture related to non-cash disposition of property	(5,897)	(17,628)
Change in operating real estate related to non-cash adjustment to land	0	7,752
Change in receivable from settlement of acquisitions	619	0	0
Change in mortgage notes payable related to acquisition of an operating property	0	238,082	0
Change in investments in joint venture related to a contribution of land at period end	(1,182)	(6,058)	(15,222)
Change in investments in joint venture related to a contribution of services	0	0	(711)
Change in capital expenditures financed through accounts payable at period end	7,336	11,703	7,059
Change in capital expenditures financed through retention payable at period end	6,164	(204)	566
Change in unfunded tenant allowance	$ (955)	$ (969)	$ (1,089)