Consolidated Debt Obligations Abstract.

No definition available.

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- Definition

Secured debt net of premiums discount.

+ References

No definition available.

+ Details

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- Definition

Total unsecured indebtedness.

+ References

No definition available.

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- Definition

Amount of long-term debt before deduction of unamortized discount or premium. Includes, but is not limited to, notes payable, bonds payable, commercial loans, mortgage loans, convertible debt, subordinated debt and other types of debt, with initial maturities beyond one year or the normal operating cycle, if longer.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.22)
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Section 02
-Paragraph 20
-Article 5

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Section 03
-Paragraph 16
-Article 9

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- Definition

Effective interest rate for the funds borrowed under the debt agreement considering interest compounding and original issue discount or premium.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.22(a)(1))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 45
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=6451184&loc=d3e28551-108399

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- Definition

Date when the debt instrument is scheduled to be fully repaid, in CCYY-MM-DD format.

+ References

+ Details

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- Definition

The amount of debt discount (net of debt premium) that was originally recognized at the issuance of the instrument that has yet to be amortized.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 45
-Paragraph 4
-URI http://asc.fasb.org/extlink&oid=6451184&loc=d3e28567-108399

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 45
-Paragraph 1A
-URI http://asc.fasb.org/extlink&oid=6451184&loc=d3e28541-108399

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 55
-Paragraph 8
-URI http://asc.fasb.org/extlink&oid=34725769&loc=d3e28878-108400

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 45
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=6451184&loc=d3e28551-108399

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-URI http://asc.fasb.org/extlink&oid=6451184&loc=d3e28555-108399

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- Definition

For an unclassified balance sheet, the carrying amount (net of accumulated amortization) as of the balance sheet date of capitalized costs associated with the issuance of debt instruments (for example, legal, accounting, underwriting, printing, and registration costs) that will be charged against earnings over the life of the debt instruments to which such costs pertain.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 45
-Paragraph 3
-URI http://asc.fasb.org/extlink&oid=6451184&loc=d3e28555-108399

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.17)
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

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- Definition

Carrying amount of long-term debt, net of unamortized discount or premium, including current and noncurrent amounts. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03.16)
-URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.22)
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-03.16)
-URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910

Reference 4: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Section 02
-Paragraph 20, 22
-Article 5

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Debt Obligations - Consolidated Debt Obligations Outstanding (Details) - USD ($) $ in Thousands		3 Months Ended	9 Months Ended	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2015	Oct. 07, 2015	Dec. 31, 2015	Oct. 08, 2015	Dec. 31, 2014
Consolidated debt obligations
Plus: premiums/(discounts), net	$ (8,912)	$ (8,912)		$ (8,912)
Less: deferred financing costs	(22,595)	(22,595)		(22,595)
Total Debt Obligations	$ 2,384,717	$ 2,384,717		$ 2,384,717		$ 2,427,345
Effective interest rate	0.00%	0.00%		0.00%
Secured Debt [Member]
Consolidated debt obligations
Long-term Debt, Gross	$ 562,695	$ 562,695		$ 562,695		655,934
Plus: premiums/(discounts), net	(3,198)	(3,198)		(3,198)		(1,344)
Less: deferred financing costs	(13,744)	(13,744)		(13,744)		(14,959)
Total mortgage indebtedness	545,753	545,753		545,753		639,631
Unsecured Debt [Member]
Consolidated debt obligations
Long-term Debt, Gross	1,853,529	1,853,529		1,853,529		1,803,529
Plus: premiums/(discounts), net	(5,714)	(5,714)		(5,714)		(6,811)
Less: deferred financing costs	(8,851)	(8,851)		(8,851)		(9,004)
Total unsecured indebtedness	1,838,964	1,838,964		1,838,964		1,787,714
Tysons Corner [Member] \| Secured Debt [Member]
Consolidated debt obligations
Long-term Debt, Gross	$ 0	$ 0		$ 0		89,513
Effective interest rate	5.36%	5.36%		5.36%
Debt Instrument Maturity Date				Oct. 09, 2015
Two Logan Square [Member] \| Secured Debt [Member]
Consolidated debt obligations
Long-term Debt, Gross	$ 86,886	$ 86,886		$ 86,886		87,767
Effective interest rate	7.57%	7.57%		7.57%
Debt Instrument Maturity Date				Apr. 01, 2016
Fairview Eleven Tower [Member] \| Secured Debt [Member]
Consolidated debt obligations
Long-term Debt, Gross	$ 20,838	$ 20,838		$ 20,838		21,242
Effective interest rate	4.25%	4.25%		4.25%
Debt Instrument Maturity Date				Jan. 01, 2017
One Commerce Square [Member] \| Secured Debt [Member]
Consolidated debt obligations
Long-term Debt, Gross	$ 130,000	$ 130,000		$ 130,000		123,205
Effective interest rate	3.64%	3.64%		3.64%
Debt Instrument Maturity Date	Apr. 05, 2023			Jan. 06, 2016
Two Commerce Square [Member] \| Secured Debt [Member]
Consolidated debt obligations
Long-term Debt, Gross	$ 112,000	$ 112,000		$ 112,000		112,000
Effective interest rate	4.51%	4.51%		4.51%
Debt Instrument Maturity Date				Apr. 05, 2023
IRS Philadelphia Campus [Member] \| Secured Debt [Member]
Consolidated debt obligations
Long-term Debt, Gross	$ 177,425	$ 177,425		$ 177,425		184,442
Effective interest rate	7.00%	7.00%		7.00%
Debt Instrument Maturity Date				Sep. 10, 2030
Cira South Garage [Member] \| Secured Debt [Member]
Consolidated debt obligations
Long-term Debt, Gross	$ 35,546	$ 35,546		$ 35,546		37,765
Effective interest rate	7.12%	7.12%		7.12%
Debt Instrument Maturity Date				Sep. 10, 2030
Seven Year Term Loan - Swapped to fixed [Member] \| Unsecured Debt [Member]
Consolidated debt obligations
Long-term Debt, Gross	$ 250,000	$ 250,000	$ 200,000	$ 250,000	$ 250,000	200,000
Effective interest rate	3.72%	3.72%		3.72%	3.72%
Debt Instrument Maturity Date		Oct. 08, 2022	Feb. 01, 2019
$250.0M 6.00% Guaranteed Notes due 2016 [Member] \| Unsecured Debt [Member]
Consolidated debt obligations
Long-term Debt, Gross	$ 149,919	$ 149,919		$ 149,919		149,919
Effective interest rate	5.95%	5.95%		5.95%
Debt Instrument Maturity Date				Apr. 01, 2016
$300.0M 5.70% Guaranteed Notes due 2017 [Member] \| Unsecured Debt [Member]
Consolidated debt obligations
Long-term Debt, Gross	$ 300,000	$ 300,000		$ 300,000		300,000
Effective interest rate	5.68%	5.68%		5.68%
Debt Instrument Maturity Date				May 01, 2017
$325.0M 4.95% Guaranteed Notes due 2018 [Member] \| Unsecured Debt [Member]
Consolidated debt obligations
Long-term Debt, Gross	$ 325,000	$ 325,000		$ 325,000		325,000
Effective interest rate	5.13%	5.13%		5.13%
Debt Instrument Maturity Date				Apr. 15, 2018
$250M 3.95% Guaranteed Notes due 2023 [Member] \| Unsecured Debt [Member]
Consolidated debt obligations
Long-term Debt, Gross	$ 250,000	$ 250,000		$ 250,000		250,000
Effective interest rate	4.02%	4.02%		4.02%
Debt Instrument Maturity Date				Feb. 15, 2023
250.0M 4.10% Guaranteed Notes due 2024 [Member] \| Unsecured Debt [Member]
Consolidated debt obligations
Long-term Debt, Gross	$ 250,000	$ 250,000		$ 250,000		250,000
Effective interest rate	4.33%	4.33%		4.33%
Debt Instrument Maturity Date				Oct. 01, 2024
$250M 4.55% Guaranteed Notes due 2029 [Member] \| Unsecured Debt [Member]
Consolidated debt obligations
Long-term Debt, Gross	$ 250,000	$ 250,000		$ 250,000		250,000
Effective interest rate	4.60%	4.60%		4.60%
Debt Instrument Maturity Date				Oct. 01, 2029
Indenture IA (Preferred Trust I) [Member] \| Unsecured Debt [Member]
Consolidated debt obligations
Long-term Debt, Gross	$ 27,062	$ 27,062		$ 27,062		27,062
Effective interest rate	2.75%	2.75%		2.75%
Debt Instrument Maturity Date				Mar. 30, 2035
Indenture IB (Preferred Trust I) [Member] \| Unsecured Debt [Member]
Consolidated debt obligations
Long-term Debt, Gross	$ 25,774	$ 25,774		$ 25,774		25,774
Effective interest rate	3.30%	3.30%		3.30%
Debt Instrument Maturity Date				Apr. 30, 2035
Indenture II (Preferred Trust II) [Member] \| Unsecured Debt [Member]
Consolidated debt obligations
Long-term Debt, Gross	$ 25,774	$ 25,774		$ 25,774		$ 25,774
Effective interest rate	3.09%	3.09%		3.09%
Debt Instrument Maturity Date				Jul. 30, 2035