Net Income (Loss) Available to Common Unitholders Per Unit of the Operating Partnership (Details) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended
	Mar. 31, 2014		Mar. 31, 2013
Numerator:
Income from continuing operations	$ 11,440		$ 186
Preferred distributions	(3,313)		(3,313)
Allocation to participating securities	(427)	[1]	(418)	[1]
Numerator for basic and diluted income (loss) from continuing operations available to common unitholders	7,528		(3,473)
Income from discontinued operations	90,492		2,202
Numerator for basic and diluted net income (loss) available to common unitholders	96,105		(1,321)
Denominator:
Weighted average common units outstanding - basic (Note 14)	82,124,538		74,977,240
Effect of dilutive securities	2,015,532		0
Weighted average common units outstanding - diluted (Note 14)	84,140,070		74,977,240
Basic earnings per unit:
Income (loss) from continuing operations available to common unitholders per common unit - basic (Note 15)	$ 0.09		$ (0.05)
Income from discontinued operations per common unit	$ 1.08		$ 0.03
Net income (loss) available to common unitholders per unit-basic (Note 14)	$ 1.17		$ (0.02)
Diluted earnings per unit:
Income (loss) from continuing operations available to common unitholders per common unit - diluted (Note 15)	$ 0.09		$ (0.05)
Income from discontinued operations per common unit	$ 1.05		$ 0.03
Net income (loss) available to common unitholders per unit-diluted (Note 14)	$ 1.14		$ (0.02)
Stock options outstanding	1,520,500
Kilroy Realty, L.P. [Member]
Numerator:
Income from continuing operations	11,440		186
Income from continuing operations attributable to noncontrolling interests in consolidated subsidiaries	(65)		(69)
Preferred distributions	(3,313)		(3,313)
Allocation to participating securities	(427)	[1]	(418)	[1]
Numerator for basic and diluted income (loss) from continuing operations available to common unitholders	7,635		(3,614)
Income from discontinued operations	90,492		2,202
Numerator for basic and diluted net income (loss) available to common unitholders	$ 98,127		$ (1,412)
Denominator:
Weighted average common units outstanding - basic (Note 14)	83,928,993		76,803,743
Effect of dilutive securities	2,015,532		0
Weighted average common units outstanding - diluted (Note 14)	85,944,525		76,803,743
Basic earnings per unit:
Income (loss) from continuing operations available to common unitholders per common unit - basic (Note 15)	$ 0.09		$ (0.05)
Income from discontinued operations per common unit	$ 1.08		$ 0.03
Net income (loss) available to common unitholders per unit-basic (Note 14)	$ 1.17		$ (0.02)
Diluted earnings per unit:
Income (loss) from continuing operations available to common unitholders per common unit - diluted (Note 15)	$ 0.09		$ (0.05)
Income from discontinued operations per common unit	$ 1.05		$ 0.03
Net income (loss) available to common unitholders per unit-diluted (Note 14)	$ 1.14		$ (0.02)

[1] Participating securities include nonvested shares, certain time-based RSUs and vested market-measure RSUs.