Consolidated Balance Sheets (KILROY REALTY, L.P.) (Parenthetical) - Kilroy Realty, L.P. [Member] - USD ($)	3 Months Ended	12 Months Ended
	Mar. 31, 2016	Dec. 31, 2015
Series G Cumulative Redeemable Preferred Units [Member]
Preferred Units, Issued	4,000,000	4,000,000
Preferred Units, Outstanding	4,000,000	4,000,000
Preferred stock dividend rate percentage	6.875%	6.875%
Preferred Stock Liquidation preference	$ 100,000,000	$ 100,000,000
Series H Cumulative Redeemable Preferred Units [Member]
Preferred Units, Issued	4,000,000	4,000,000
Preferred Units, Outstanding	4,000,000	4,000,000
Preferred stock dividend rate percentage	6.375%	6.375%
Preferred Stock Liquidation preference	$ 100,000,000	$ 100,000,000
Common Units [Member]
General partner, units issued	92,229,464	92,258,690
General partners, units outstanding	92,229,464	92,258,690
Limited partners, units issued	2,631,276	1,764,775
Noncontrolling common units of the Operating Partnership	2,631,276	1,764,775