Net Income Available to Common Unitholders Per Unit of the Operating Partnership (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Numerator:
Net income available to common unitholders	$ 53,128	$ 497,631
Allocation to participating securities	(413)	(365)
Numerator for basic and diluted net income available to common stockholders	$ 52,715	$ 497,266
Denominator:
Basic weighted average vested units outstanding (in shares)	116,650,228	116,344,375
Effect of dilutive securities (in shares)	409,866	457,009
Diluted weighted average vested shares and common stock equivalents outstanding (in shares)	117,060,094	116,801,384
Basic earnings per unit:
Net income available to common stockholders per unit (in dollars per share)	$ 0.45	$ 4.27
Diluted earnings per unit:
Net income available to common stockholders per unit (in dollars per share)	$ 0.45	$ 4.26
Kilroy Realty L.P.
Numerator:
Net income available to common unitholders	$ 53,644	$ 502,517
Allocation to participating securities	(413)	(365)
Numerator for basic and diluted net income available to common stockholders	$ 53,231	$ 502,152
Denominator:
Basic weighted average vested units outstanding (in shares)	117,800,802	117,494,949
Effect of dilutive securities (in shares)	409,866	457,009
Diluted weighted average vested shares and common stock equivalents outstanding (in shares)	118,210,668	117,951,958
Basic earnings per unit:
Net income available to common stockholders per unit (in dollars per share)	$ 0.45	$ 4.27
Diluted earnings per unit:
Net income available to common stockholders per unit (in dollars per share)	$ 0.45	$ 4.26