Consolidated Balance Sheets (KILROY REALTY, L.P.) (Parenthetical) (Kilroy Realty, L.P. [Member], USD $) In Thousands, except Share data, unless otherwise specified			12 Months Ended			12 Months Ended		12 Months Ended		12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2011 Series A Preferred Units [Member]	Dec. 31, 2011 Series E Cumulative Redeemable Preferred Unit [Member]	Dec. 31, 2012 Series E Cumulative Redeemable Preferred Unit [Member]	Dec. 31, 2011 Series F Cumulative Redeemable Preferred Unit [Member]	Dec. 31, 2012 Series F Cumulative Redeemable Preferred Unit [Member]	Dec. 31, 2012 Series G Cumulative Redeemable Preferred Unit [Member]	Mar. 31, 2012 Series G Cumulative Redeemable Preferred Unit [Member]	Dec. 31, 2012 Series H Cumulative Redeemable Preferred Unit [Member]	Aug. 31, 2012 Series H Cumulative Redeemable Preferred Unit [Member]
General Partners' Capital Account, Units Issued	74,926,981	58,819,717
General Partners' Capital Account, Units Outstanding	74,926,981	58,819,717
Limited Partners' Capital Account, Units Issued	1,826,503	1,718,131
Common units held by limited partners	1,826,503	1,718,131
Preferred stock dividend rate percentage			7.45%	7.80%		7.50%		6.875%		6.375%
Preferred Units, Issued				1,610,000		3,450,000		4,000,000	4,000,000	4,000,000	4,000,000
Preferred units outstanding				1,610,000		3,450,000		4,000,000		4,000,000
Preferred stock liquidation preference				$ 40,250		$ 86,250		$ 100,000		$ 100,000