Consolidated Balance Sheets (KILROY REALTY, L.P.) (Parenthetical) (Kilroy Realty, L.P. [Member], USD $) In Thousands, except Share data, unless otherwise specified			3 Months Ended	12 Months Ended	3 Months Ended	12 Months Ended	3 Months Ended	12 Months Ended	3 Months Ended	12 Months Ended
	Mar. 31, 2012	Dec. 31, 2011	Mar. 31, 2012 Series A Cumulative Redeemable Preferred Unit [Member]	Dec. 31, 2011 Series A Cumulative Redeemable Preferred Unit [Member]	Mar. 31, 2012 Series E Cumulative Redeemable Preferred Unit [Member]	Dec. 31, 2011 Series E Cumulative Redeemable Preferred Unit [Member]	Mar. 31, 2012 Series F Cumulative Redeemable Preferred Unit [Member]	Dec. 31, 2011 Series F Cumulative Redeemable Preferred Unit [Member]	Mar. 31, 2012 Series G Cumulative Redeemable Preferred Unit [Member]	Dec. 31, 2011 Series G Cumulative Redeemable Preferred Unit [Member]
Partners' Capital (Note 9):
General partner, units issued	68,349,843	58,819,717
General partners, units outstanding	68,349,843	58,819,717
Limited partners, units issued	1,718,131	1,718,131
Common units held by limited partners	1,718,131	1,718,131
Preferred stock dividend rate percentage			7.45%	7.45%	7.80%	7.80%	7.50%	7.50%	6.875%
Preferred Stock Liquidation preference					$ 40,250	$ 40,250	$ 86,250	$ 86,250	$ 100,000	$ 0
Preferred Units, Issued					1,610,000	1,610,000	3,450,000	3,450,000	4,000,000	0
Preferred Units, Outstanding					1,610,000	1,610,000	3,450,000	3,450,000	4,000,000	0