Aggregate dividends declared during the period for each share of common stock outstanding.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
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-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section S99
-Paragraph 1
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Reference 1: http://www.xbrl.org/2003/role/presentationRef
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-Name Accounting Standards Codification
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Cash outflow to owners or shareholders, excluding ordinary dividends. Includes special dividends.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Glossary Financing Activities
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-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
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Amount of cash outflow in the form of ordinary dividends to common shareholders of the parent entity.

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The cash inflow from the additional capital contribution to the entity.

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The cash inflow from the sale of formerly productive land held for sale, anything permanently fixed to it, including buildings, structures on it, and so forth.

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The number of grants made during the period on other than stock (or unit) option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, performance target plan).

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Per share or per unit amount of equity securities issued.

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Subsequent Events (Details) - USD ($) $ / shares in Units, $ in Thousands							3 Months Ended	12 Months Ended
	Feb. 17, 2017	Jan. 13, 2017	Jan. 10, 2017	Dec. 13, 2016	Jan. 28, 2016	Jan. 27, 2015	Dec. 31, 2016	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Jul. 01, 2015
Subsequent Event [Line Items]
Dividends declared per common share				$ 1.90			$ 0.375	$ 3.375	$ 1.4	$ 1.40
Payments of dividends, common stock								$ 137,444	$ 126,839	$ 118,463
Common stock, shares issued											3,733,766
Shares issued, price per share											$ 66.19
Net proceeds from issuance of common stock								$ 31,117	$ 387,398	$ 102,229
Subsequent event [Member]
Subsequent Event [Line Items]
Payments of special cash dividend		$ 184,300
Payments of dividends, common stock		36,400
Common stock, shares issued			4,427,500
Shares issued, price per share			$ 72.75
Net proceeds from issuance of common stock			$ 308,800
Pacific Center Boulevard, Sorrento Mesa, California [Member] \| Subsequent event [Member]
Subsequent Event [Line Items]
Proceeds from sale of property held-for-sale		$ 12,100
Market measure-based Restricted Stock Units (RSUs) [Member]
Subsequent Event [Line Items]
Share-based compensation arrangement by share-based payment award, equity instruments other than options, grants in period					168,077	127,657
Market measure-based Restricted Stock Units (RSUs) [Member] \| Kilroy Realty 2006 Incentive Award Plan [Member] \| Subsequent event [Member]
Subsequent Event [Line Items]
Share-based compensation arrangement by share-based payment award, equity instruments other than options, grants in period	41,119