Consolidated Statements of Cash Fiows (Kilroy Realty, L.P.) (Parenthetical) (USD $) In Thousands, unless otherwise specified	9 Months Ended
Sep. 30, 2013	Sep. 30, 2012
Interest Paid, Capitalized	$ 23,573	$ 11,531
Kilroy Realty, L.P. [Member]
Interest Paid, Capitalized	$ 23,573	$ 11,531

The amount of cash paid during the current period for interest that is capitalized.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 230

-SubTopic 10

-Section 50

-Paragraph 2

-URI http://asc.fasb.org/extlink&oid=6367179&loc=d3e4297-108586

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 230

-SubTopic 10

-Section 45

-Paragraph 25

-Subparagraph (e)

-URI http://asc.fasb.org/extlink&oid=31042434&loc=d3e3536-108585

Name:	us-gaap_InterestPaidCapitalized
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration