Deferred Revenue and Acquisition Related Liabilities, net Deferred Revenue and Acquisition Related Liabilities, net (Textuals) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Deferred Revenue [Abstract]
Noncash amortization of deferred revenue related to tenant-funded tenant improvements	$ 9,136	$ 9,349	$ 9,689

The amortization of deferred revenue related to tenant funded tenant improvements during the period. Amortization of deferred revenue related to tenant funded tenant improvements is additional rental income over the term of the related lease and is added back to net income when calculating cash provided by (used in) operations using the indirect method.

No definition available.

Name:	krc_NoncashAmortizationOfDeferredRevenueRelatedToTenantFundedTenantImprovements
Namespace Prefix:	krc_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration