v3.3.1.900

Secured and Unsecured Debt of the Operating Partnership - Exchangeable Senior Notes (Details Textuals) | 3 Months Ended | 12 Months Ended |  |
--- | --- | --- | --- | ---
Dec. 31, 2015 USD ($) shares | Dec. 31, 2014 $ / option shares | Dec. 31, 2013 USD ($) shares | Dec. 31, 2015 USD ($) shares | Dec. 31, 2014 USD ($) $ / shares $ / option shares | Dec. 31, 2013 USD ($) $ / shares | Jun. 30, 2015 USD ($) | Nov. 13, 2014 USD ($)
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |
Average Trading Price Of The Companys Stock | $ / shares |  |  |  |  | $ 60.04 | [1] | $ 52.12 |  |
Derivative, Price Risk Option Strike Price | $ / option |  | 42.81 |  |  | 42.81 |  |  |  |
Convertible Notes Payable [Member] |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |
Debt Instrument, Periodic Payment, Interest |  |  |  |  | $ 5,608,000 |  | $ 7,331,000 |  |
Amortization of Debt Discount (Premium) |  |  |  |  | 3,769,000 |  | 4,427,000 |  |
Interest Expense, Debt |  |  |  |  | $ 9,377,000 |  | 11,758,000 |  |
Kilroy Realty, L.P. [Member] | Exchangeable Notes [Member] |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |
Long-term Debt, Gross |  |  |  |  |  |  |  |  | $ 135,500,000
Kilroy Realty, L.P. [Member] | Exchangeable Notes [Member] | Exchangeable Note Two [Member] |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |
Exchangeable note repurchased prinicipal amount |  |  | $ 0 |  |  |  | $ 0 | $ 0 |
Kilroy Realty, L.P. [Member] | Exchangeable Notes [Member] | Notes exchanged during 2014 [Member] |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |
Long-term Debt, Gross | $ 37,000,000 |  |  | $ 37,000,000 |  |  |  |  |
Common Stock |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |
Stock Issued During Period, Shares, Conversion of Convertible Securities | shares | 1,660,053 | 431,270 |  |  |  |  |  |  |
Shares of Common stock exercised in the capped call option | shares |  |  | 404,136 |  | 111,206 |  |  |  |
Stock issued during period, shares, conversion of convertible securities, net of adjustments | shares |  |  |  | 1,255,917 |  |  |  |  |
Common Stock, Issued, Net of Capped Calls | shares |  | 320,064 |  | 1,575,981 |  |  |  |  |
[1] | Period Ended November 15, 2014(1) Year Ended December 31, 2013Per share average trading price of the Company's common stock$60.04 $52.12_______________(1) Represents the maturity date of the 4.25% Exchangeable Notes.

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