Consolidated Balance Sheets (KILROY REALTY, L.P.) (Parenthetical) - Common units [Member] - Kilroy Realty L.P. [Member] - shares	Mar. 31, 2019	Dec. 31, 2018
General partner, units issued	100,967,024	100,746,988
General partners, units outstanding	100,967,024	100,746,988
Limited partners, units issued	2,023,287	2,025,287
Noncontrolling common units of the Operating Partnership	2,023,287	2,025,287