v3.3.1.900

Secured and Unsecured Debt of the Operating Partnership - Unsecured Senior Notes and Term Loan Facility (Details) - USD ($) $ in Thousands | 12 Months Ended |  |  |  |
--- | --- | --- | --- | --- | ---
Dec. 31, 2015 | Dec. 31, 2014 | Sep. 30, 2015 | Jul. 01, 2014 | Dec. 31, 2013 | Dec. 31, 2012
Debt Instrument [Line Items] |  |  |  |  |  |  |
Principal amount |  |  | $ 172,500 |  |  |  |
Net carrying amount |  | $ 1,856,590 | 1,783,121 |  |  |  |
Unsecured Debt [Member] | Thirty Nine Million Unsecured Term Loan Due July 2019 [Member] |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |
Net carrying amount |  | $ 39,000 |  |  |  |  |
Unsecured Senior Notes [Member] | Four Point Two Five Zero Percent Unsecured Senior Notes [Member] [Domain] |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |
Stated interest rate |  | 4.25% |  |  |  |  |
Unsecured Senior Notes [Member] | 3.800% Unsecured Senior Notes [Member] |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |
Stated interest rate | [1] | 3.80% |  |  |  |  |
Unsecured Senior Notes [Member] | 4.80% Unsecured Senior Notes due July 15, 2018 [Member] |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |
Stated interest rate |  | 4.80% |  |  |  |  |
Unsecured Senior Notes [Member] | 6.625% Unsecured Senior Notes due June 1, 2020 [Member] |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |
Stated interest rate |  | 6.625% |  |  |  |  |
Line of Credit [Member] | $150.0 Term Loan Facility [Member] |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |
Net carrying amount |  | $ 150,000 |  |  |  |  |
Kilroy Realty, L.P. [Member] |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |
Net carrying amount |  | 1,856,590 | 1,783,121 |  |  |  |
Kilroy Realty, L.P. [Member] | Unsecured Senior Notes [Member] |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |
Net carrying amount |  | $ 1,667,590 | 1,594,121 |  |  |  |
Kilroy Realty, L.P. [Member] | Unsecured Senior Notes [Member] | Four Point Three Seven Five Percent Unsecured Senior Notes [Member] [Domain] [Domain] |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |
Stated interest rate | [2] | 4.375% |  |  |  |  |
Effective interest rate | [3] | 4.44% |  |  |  |  |
Principal amount |  | $ 400,000 | 0 | $ 400,000 |  |  |
Unamortized discount |  | (2,159) |  | 2,200 |  |  |
Net carrying amount |  | $ 397,841 | 0 |  |  |  |
Kilroy Realty, L.P. [Member] | Unsecured Senior Notes [Member] | Four Point Two Five Zero Percent Unsecured Senior Notes [Member] [Domain] |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |
Stated interest rate | [4] | 4.25% |  |  |  |  |
Effective interest rate | [3] | 4.35% |  |  |  |  |
Principal amount |  | $ 400,000 | 400,000 |  |  |  |
Unamortized discount |  | (4,050) | (4,348) |  | $ 4,472 |  |
Net carrying amount |  | $ 395,950 | 395,652 |  |  |  |
Kilroy Realty, L.P. [Member] | Unsecured Senior Notes [Member] | 3.800% Unsecured Senior Notes [Member] |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |
Stated interest rate | [1] | 3.80% |  |  |  |  |
Effective interest rate | [3] | 3.804% |  |  |  |  |
Principal amount |  | $ 300,000 | 300,000 |  |  |  |
Unamortized discount |  | (70) | (79) |  |  |  |
Net carrying amount |  | $ 299,930 | 299,921 |  |  |  |
Kilroy Realty, L.P. [Member] | Unsecured Senior Notes [Member] | 4.80% Unsecured Senior Notes due July 15, 2018 [Member] |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |
Stated interest rate | [1],[5] | 4.80% |  |  |  |  |
Effective interest rate | [3] | 4.827% |  |  |  |  |
Principal amount |  | $ 325,000 | 325,000 |  |  |  |
Unamortized discount |  | (191) | (265) |  |  |  |
Net carrying amount |  | $ 324,809 | 324,735 |  |  |  |
Kilroy Realty, L.P. [Member] | Unsecured Senior Notes [Member] | 6.625% Unsecured Senior Notes due June 1, 2020 [Member] |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |
Stated interest rate | [6] | 6.625% |  |  |  |  |
Effective interest rate | [3] | 6.743% |  |  |  |  |
Principal amount |  | $ 250,000 | 250,000 |  |  |  |
Unamortized discount |  | (940) | (1,154) |  |  |  |
Net carrying amount |  | $ 249,060 | 248,846 |  |  |  |
Kilroy Realty, L.P. [Member] | Unsecured Senior Notes [Member] | 5.00% Unsecured Senior Notes due Nov 3, 2015 [Member] |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |
Stated interest rate | [7] | 5.00% |  |  |  |  |
Effective interest rate | [3] | 5.014% |  |  |  |  |
Principal amount |  |  | 325,000 | 0 |  |  |
Unamortized discount |  |  | (33) | 0 |  |  |
Net carrying amount |  | $ 0 | $ 324,967 |  |  |  |
Kilroy Realty, L.P. [Member] | Unsecured Senior Notes [Member] | 6.45% Unsecured Senior Notes due Aug 4 2014 [Member] |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |
Effective interest rate |  |  |  |  |  | 6.45% | 6.45%
Net carrying amount |  |  |  |  |  | $ 83,000 |
Kilroy Realty, L.P. [Member] | Line of Credit [Member] | $150.0 Term Loan Facility [Member] |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |
Maturity date |  | Jul. 01, 2019 | Jul. 01, 2019 |  |  |  |
Net carrying amount |  | $ 150,000 | $ 150,000 |  |  |  |
Spread on variable rate | [8] | 1.40% | 1.56% |  |  |  |
Kilroy Realty, L.P. [Member] | Line of Credit [Member] | Thirty Nine Million Unsecured Term Loan Due July 2019 [Member] |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |
Net carrying amount |  |  |  | $ 39,000 |  |  |
[1] | Interest on these notes is payable semi-annually in arrears on January 15th and July 15th of each year.
[2] | Interest on these notes is payable semi-annually in arrears on April 1st and October 1st of each year.
[3] | This represents the rate at which interest expense is recorded for financial reporting purposes, which reflects the amortization of initial issuance discounts, excluding debt issuance costs.
[4] | Interest on these notes is payable semi-annually in arrears on February 15th and August 15th of each year.
[5] | In October 2015, certain common limited partners in the Operating Partnership that previously contributed their interests in the property at 6255 W. Sunset Blvd., Los Angeles, California to the Operating Partnership entered into an agreement with the Company. Pursuant to this agreement, such common limited partners will reimburse the Company for a portion of any amounts the Company may be required to pay pursuant to its guarantee of the Operating Partnership's 4.800% Senior Notes due 2018 or that the Company may otherwise become required to pay under applicable law with respect to such notes.
[6] | Interest on these notes is payable semi-annually in arrears on June 1st and December 1st of each year.
[7] | Interest of these notes is payable semi-annually in arrears on May 3rd and November 3rd of each year.
[8] | Our unsecured term loan facility interest rate was calculated based on an annual rate of LIBOR plus 1.150% and LIBOR plus 1.400% as of December 31, 2015 and December 31, 2014, respectively.

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