Consolidated Statements of Operations - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
REVENUES
Revenue	$ 187,072	$ 180,598	$ 369,894	$ 359,906
EXPENSES
Real estate taxes	17,813	16,543	34,959	34,507
Provision for bad debts (Note 12)	5,641	409	5,376	1,707
Ground leases	1,586	1,547	3,147	3,189
General and administrative expenses	21,763	14,303	37,322	29,236
Depreciation and amortization	64,006	62,251	126,721	123,170
Total expenses	143,376	128,357	271,763	256,354
OTHER (EXPENSES) INCOME
Interest income and other net investment gain/loss (Note 11)	771	1,038	805	2,103
Interest expense (Note 5)	(12,712)	(17,973)	(26,210)	(35,325)
Total other (expenses) income	(11,941)	(16,935)	(25,405)	(33,222)
INCOME FROM OPERATIONS BEFORE GAINS ON SALES OF REAL ESTATE	31,755	35,306	72,726	70,330
Gains on sales of depreciable operating properties	0	0	0	2,257
NET INCOME	31,755	35,306	72,726	72,587
Net income attributable to noncontrolling common units of the Operating Partnership	(566)	(616)	(1,317)	(1,239)
Net income attributable to noncontrolling interests in consolidated property partnerships	(3,640)	(3,242)	(7,614)	(6,375)
Total income attributable to noncontrolling interests	(4,206)	(3,858)	(8,931)	(7,614)
NET INCOME ATTRIBUTABLE TO KILROY REALTY CORPORATION (KILROY REALTY, L.P.)	27,549	31,448	63,795	64,973
Preferred dividends	0	(1,615)	0	(4,966)
Original issuance costs of redeemed preferred stock and preferred units	0	0	0	(3,845)
Total preferred dividends	0	(1,615)	0	(8,811)
NET INCOME AVAILABLE TO COMMON STOCKHOLDERS (UNITHOLDERS)	$ 27,549	$ 29,833	$ 63,795	$ 56,162
Net income available to common stockholders per share – basic (in dollars per share) (Note 13)	$ 0.27	$ 0.30	$ 0.63	$ 0.56
Net income available to common stockholders per share – diluted (in dollars per share) (Note 13)	$ 0.27	$ 0.30	$ 0.63	$ 0.56
Weighted average common shares outstanding – basic (in shares) (Note 13)	99,691,700	98,275,471	99,220,577	97,834,255
Weighted average common shares outstanding – diluted (in shares) (Note 13)	100,150,856	98,827,378	99,687,682	98,427,345
Dividends declared per common share (in dollars per share)	$ 0.455	$ 0.425000	$ 0.88	$ 0.8
Rental [Member]
REVENUES
Revenue	$ 164,515	$ 158,925	$ 327,386	$ 315,573
Tenant reimbursements [Member]
REVENUES
Revenue	19,567	19,267	38,717	38,563
Other property income [Member]
REVENUES
Revenue	2,990	2,406	3,791	5,770
Property [Member]
EXPENSES
Property expenses	$ 32,567	$ 33,304	$ 64,238	$ 64,545