Cash outflow in the form of capital distributions and dividends to common shareholders, preferred shareholders and noncontrolling interests.

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-Publisher FASB
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-Topic 230
-SubTopic 10
-Section 45
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Estimated period over which an employee is required to provide service in exchange for the equity-based payment award, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
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The difference between the maximum number of shares (or other type of equity) authorized for issuance under the plan (including the effects of amendments and adjustments), and the sum of: 1) the number of shares (or other type of equity) already issued upon exercise of options or other equity-based awards under the plan; and 2) shares (or other type of equity) reserved for issuance on granting of outstanding awards, net of cancellations and forfeitures, if applicable.

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-SubTopic 10
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-Paragraph 2
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Detail information of subsequent event by type. User is expected to use existing line items from elsewhere in the taxonomy as the primary line items for this disclosure, which is further associated with dimension and member elements pertaining to a subsequent event.

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Subsequent Events - Narrative (Details) - USD ($) $ in Millions	Jan. 31, 2020	Jan. 15, 2020	Dec. 31, 2019
Kilroy Realty 2006 Incentive Award Plan [Member]
Subsequent Event [Line Items]
Share-based compensation arrangement by share-based payment award, number of shares available for grant			400,000
Subsequent event [Member]
Subsequent Event [Line Items]
Payments of dividends		$ 53.2
Subsequent event [Member] \| Kilroy Realty 2006 Incentive Award Plan [Member] \| Time-Based Restricted Stock Units (RSUs) [Member] \| Chief Executive Officer [Member]
Subsequent Event [Line Items]
Share-based compensation arrangement by share-based payment award, number of shares available for grant	109,359
Subsequent event [Member] \| Kilroy Realty 2006 Incentive Award Plan [Member] \| Market measure-based Restricted Stock Units (RSUs) [Member] \| Chief Executive Officer [Member]
Subsequent Event [Line Items]
Share-based compensation arrangement by share-based payment award, number of shares available for grant	154,267
Recognition period	3 years