v2.4.0.8

Subsequent Events subsequent Events (Details) (USD $) | 9 Months Ended |  |  |  |  |  |  |  |  |  |  |  |  | 0 Months Ended |  |  |  |  |  |  |  |  |  | 0 Months Ended |
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Sep. 30, 2014 | Sep. 30, 2013 | Nov. 01, 2014 535 Mission Street [Member] Subsequent Event [Member] sqft | Oct. 22, 2014 415 Main Street (formerly Seven Cambridge Center) [Member] Subsequent Event [Member] sqft leaseyear | Nov. 06, 2014 425 Main Street [Member] Subsequent Event [Member] | Jun. 11, 2014 Patriots park [Member] Buildings sqft | Oct. 02, 2014 Patriots park [Member] Subsequent Event [Member] sqft Buildings | Oct. 24, 2014 130 Third Avenue [Member] Subsequent Event [Member] sqft | Sep. 30, 2014 Noncontrolling Interests [Member] | Sep. 30, 2014 Series Four Preferred Units [Member] Noncontrolling Interests [Member] | Jul. 03, 2014 Series Four Preferred Units [Member] Noncontrolling Interests [Member] | May 19, 2014 Series Four Preferred Units [Member] Noncontrolling Interests [Member] | Nov. 05, 2014 Series Four Preferred Units [Member] Noncontrolling Interests [Member] Subsequent Event [Member] | Oct. 16, 2014 Series Four Preferred Units [Member] Noncontrolling Interests [Member] Subsequent Event [Member] | Oct. 24, 2014 Annapolis Junction Building Six [Member] Subsequent Event [Member] sqft | Oct. 24, 2014 Construction Loans [Member] Annapolis Junction Building Six [Member] Subsequent Event [Member] | Oct. 23, 2014 Construction Loans [Member] Annapolis Junction Building Six [Member] Subsequent Event [Member] | Oct. 24, 2014 Construction Loans [Member] Annapolis Junction Building Six [Member] Subsequent Event [Member] | Sep. 16, 2014 Consolidated Properties [Member] 601 Lexington Avenue, Atlantic Wharf Office Building and One Hundred Federal Street [Member] | Oct. 30, 2014 Consolidated Properties [Member] 601 Lexington Avenue, Atlantic Wharf Office Building and One Hundred Federal Street [Member] Subsequent Event [Member] | Sep. 16, 2014 Consolidated Properties [Member] 601 Lexington Avenue, Atlantic Wharf Office Building and One Hundred Federal Street [Member] 601 Lexington Avenue [Member] sqft | Oct. 30, 2014 Consolidated Properties [Member] 601 Lexington Avenue, Atlantic Wharf Office Building and One Hundred Federal Street [Member] 601 Lexington Avenue [Member] Subsequent Event [Member] sqft | Sep. 16, 2014 Consolidated Properties [Member] 601 Lexington Avenue, Atlantic Wharf Office Building and One Hundred Federal Street [Member] Atlantic Wharf Office [Member] sqft | Oct. 30, 2014 Consolidated Properties [Member] 601 Lexington Avenue, Atlantic Wharf Office Building and One Hundred Federal Street [Member] Atlantic Wharf Office [Member] Subsequent Event [Member] sqft | Sep. 16, 2014 Consolidated Properties [Member] 601 Lexington Avenue, Atlantic Wharf Office Building and One Hundred Federal Street [Member] 100 Federal Street [Member] sqft | Oct. 30, 2014 Consolidated Properties [Member] 601 Lexington Avenue, Atlantic Wharf Office Building and One Hundred Federal Street [Member] 100 Federal Street [Member] Subsequent Event [Member] sqft | Sep. 16, 2014 Office Tower [Member] Consolidated Properties [Member] 601 Lexington Avenue, Atlantic Wharf Office Building and One Hundred Federal Street [Member] 601 Lexington Avenue [Member] floor | Oct. 30, 2014 Office Tower [Member] Consolidated Properties [Member] 601 Lexington Avenue, Atlantic Wharf Office Building and One Hundred Federal Street [Member] 601 Lexington Avenue [Member] Subsequent Event [Member] floor | Sep. 16, 2014 Low Rise [Member] Consolidated Properties [Member] 601 Lexington Avenue, Atlantic Wharf Office Building and One Hundred Federal Street [Member] 601 Lexington Avenue [Member] floor | Oct. 30, 2014 Low Rise [Member] Consolidated Properties [Member] 601 Lexington Avenue, Atlantic Wharf Office Building and One Hundred Federal Street [Member] 601 Lexington Avenue [Member] Subsequent Event [Member] floor | Nov. 03, 2014 Unsecured Debt [Member] Subsequent Event [Member] 5.625% Unsecured Senior Notes [Member] | Nov. 03, 2014 Unsecured Debt [Member] Subsequent Event [Member] 5% Unsecured Senior Notes [Member]
Subsequent Event [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Sales price |  |  |  |  |  | $ 321,000,000 | $ 321,000,000 | $ 14,300,000 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Ownership Percentage |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 50.00% |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Construction Loan |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 13,900,000 |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument, Basis Spread on Variable Rate |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 2.25% | 1.65% |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Construction Loan Facility Borrowing Capacity |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 16,400,000 |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument, Description of Variable Rate Basis |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | LIBOR | LIBOR |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Area of Real Estate Property |  |  | 307,000 | 231,000 |  | 706,000 | 706,000 | 129,000 |  |  |  |  |  |  | 119,000 |  |  |  |  |  | 1,669,000 | 1,669,000 | 791,000 | 791,000 | 1,323,000 | 1,323,000 |  |  |  |  |  |
Series Four Preferred Units Released from Escrow |  |  |  |  |  |  |  |  |  |  |  | 319,687 |  | 27,773 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Redemption of Series Four Preferred Units |  |  |  |  |  |  |  |  |  |  | 16,000,000 |  | 1,400,000 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Series Four Preferred Units (in shares) |  |  |  |  |  |  |  |  | 40,440 | 40,440 | 40,440 |  | 12,667 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Purchase Option Price for Real Estate Property |  |  |  | 106,000,000 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Purchase option date (lease year) |  |  |  | 11 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Repayments of Secured Debt | 82,030,000 | 96,750,000 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Coupon/Stated Rate |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 5.625% | 5.00%
Number of real estate properties |  |  |  |  |  | 3 | 3 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Ownership Percentage |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 45.00% | 45.00% |  |  |  |  |  |  |  |  |  |  |  |
Gross Sales Price Before Deducting Indebtedness |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 1,827,000,000 | 1,827,000,000 |  |  |  |  |  |  |  |  |  |  |  |
Number of floors real estate |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 59 | 59 | 6 | 6 |  |
Secured Debt Carrying Value |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 712,900,000 | 712,900,000 |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument, Repurchased Face Amount |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 300,000,000 | 250,000,000
Basis Points Added to US Treasury Security Used in Redemption Price |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 0.35% | 0.25%
Non-refundable option payment |  |  |  |  | $ 1,000,000 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |

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- Definition Basis Points Added to US Treasury Security Used in Redemption Price + References No definition available. + Details
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- Definition Construction Loan Facility Borrowing Capacity + References No definition available. + Details
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- Definition Amount of consideration received or receivable for the disposal of assets and liabilities, including discontinued operation before deducting indebtedness. + References No definition available. + Details
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- Definition Amount classified as secured debt attributable to disposal group held for sale or disposed of. + References No definition available. + Details
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- Definition Non-refundable option payment + References No definition available. + Details
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- Definition Number of floors real estate + References No definition available. + Details
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- Definition Purchase option date (lease year) + References No definition available. + Details
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- Definition Purchase Option Price for Real Estate Property + References No definition available. + Details
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- Definition Redemption of Series Four Preferred Units + References No definition available. + Details
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- Definition Series Four Preferred Units + References No definition available. + Details
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- Definition Series Four Preferred Units Released from Escrow + References No definition available. + Details
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- Definition Area of a real estate property. + References No definition available. + Details
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- Definition This element represents the carrying value of a short-term real estate loan to finance building costs. The funds are disbursed as needed or in accordance with a prearranged plan; generally, a portion of the funds is disbursed at inception and the remainder as construction progresses. The money is repaid on completion of the project, usually from the proceeds of a mortgage loan. The rate is normally higher than the prime rate, and there is usually an origination fee. The effective yield on these loans tends to be high, and the lender has a security interest in the real property. Note that there are separate concepts for the current and noncurrent portions of long-term construction loans. + 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 210.5-02.19(a)(1)) -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 19, 20 -Article 5 + Details
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- Definition Percentage points added to the reference rate to compute the variable rate on the debt instrument. + References No definition available. + Details
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- Definition The reference rate for the variable rate of the debt instrument, such as LIBOR or the US Treasury rate and the maturity of the reference rate used, such as three months or six months LIBOR. + References No definition available. + Details
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- Definition Contractual interest rate for funds borrowed, under the debt agreement. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 22 -Article 5 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(a)(1)) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 + Details
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- Definition Face (par) amount of the original debt instrument that was repurchased. + References No definition available. + Details
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- Definition Amount of consideration received or receivable for the disposal of assets and liabilities, including discontinued operation. + References No definition available. + Details
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- Definition The percentage of ownership of common stock or equity participation in the investee accounted for under the equity method of accounting. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 323 -SubTopic 10 -Section 50 -Paragraph 3 -Subparagraph (a)(1) -URI http://asc.fasb.org/extlink&oid=6382943&loc=d3e33918-111571 + Details
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- Definition The equity interest of noncontrolling shareholders, partners or other equity holders in consolidated entity. + References No definition available. + Details
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- Definition The number of real estate properties owned as of the balance sheet date. + References No definition available. + Details
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- Definition The cash outflow to repay long-term debt that is wholly or partially secured by collateral. Excludes repayments of tax exempt secured debt. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 15 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=31042434&loc=d3e3291-108585 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Glossary Financing Activities -URI http://asc.fasb.org/extlink&oid=6513228 + Details
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