Supplemental Cash Flow Information of the Operating Partnership - Reconciliation of Cash and Cash Equivalents and Restricted Cash (Details) - USD ($) $ in Thousands	Mar. 31, 2023	Dec. 31, 2022	Mar. 31, 2022	Dec. 31, 2021
RECONCILIATION OF CASH AND CASH EQUIVALENTS AND RESTRICTED CASH:
Cash and cash equivalents	$ 476,358	$ 347,379	$ 331,685	$ 414,077
Restricted cash	0	0	13,007	13,006
Cash and cash equivalents and restricted cash	476,358	347,379	344,692	427,083
Kilroy Realty L.P.
RECONCILIATION OF CASH AND CASH EQUIVALENTS AND RESTRICTED CASH:
Cash and cash equivalents	476,358	347,379	331,685	414,077
Restricted cash	0	0	13,007	13,006
Cash and cash equivalents and restricted cash	$ 476,358	$ 347,379	$ 344,692	$ 427,083

Amount of cash and cash equivalents restricted as to withdrawal or usage. Cash includes, but is not limited to, currency on hand, demand deposits with banks or financial institutions, and other accounts with general characteristics of demand deposits. Cash equivalents include, but are not limited to, short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates.

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant