CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
REAL ESTATE ASSETS:
Land and improvements	$ 1,612,224	$ 1,466,166
Buildings and improvements	6,535,637	5,866,477
Undeveloped land and construction in progress	1,938,923	2,296,130
Total real estate assets held for investment	10,086,784	9,628,773
Accumulated depreciation and amortization	(1,744,325)	(1,561,361)
Total real estate assets held for investment, net	8,342,459	8,067,412
CASH AND CASH EQUIVALENTS (Note 4)	849,009	60,044
RESTRICTED CASH	16,300	16,300
MARKETABLE SECURITIES (Note 10)	25,073	27,098
CURRENT RECEIVABLES, NET	16,083	26,489
DEFERRED RENT RECEIVABLES, NET	375,939	337,937
DEFERRED LEASING COSTS AND ACQUISITION-RELATED INTANGIBLE ASSETS, NET	208,306	212,805
RIGHT OF USE GROUND LEASE ASSETS (Note 9)	95,733	96,348
PREPAID EXPENSES AND OTHER ASSETS, NET (Note 2)	55,706	55,661
TOTAL ASSETS	9,984,608	8,900,094
LIABILITIES:
Secured debt, net (Notes 3 and 10)	254,854	258,593
Unsecured debt, net (Notes 3, and 10)	3,668,976	3,049,185
Unsecured line of credit (Notes 3 and 10)	0	245,000
Accounts payable, accrued expenses and other liabilities	458,421	418,848
Ground lease liabilities (Note 9)	97,936	98,400
Accrued dividends and distributions (Note 15)	59,416	53,219
Deferred revenue and acquisition-related intangible liabilities, net	131,558	139,488
Rents received in advance and tenant security deposits	61,483	66,503
Total liabilities	4,732,644	4,329,236
COMMITMENTS AND CONTINGENCIES (Note 9)
Stockholders’ Equity (Note 4):
Common stock, $.01 par value, 280,000,000 and 150,000,000 shares authorized, respectively, 115,247,221 and 106,016,287 shares issued and outstanding, respectively	1,152	1,060
Additional paid-in capital	5,089,926	4,350,917
Distributions in excess of earnings	(122,936)	(58,467)
Total stockholders’ equity	4,968,142	4,293,510
Noncontrolling Interests (Notes 1 and 5):
Common units of the Operating Partnership	83,226	81,917
Noncontrolling interests in consolidated property partnerships	200,596	195,431
Total noncontrolling interests	283,822	277,348
Total equity	5,251,964	4,570,858
TOTAL LIABILITIES AND EQUITY (CAPITAL)	9,984,608	8,900,094
Kilroy Realty L.P. [Member]
REAL ESTATE ASSETS:
Land and improvements	1,612,224	1,466,166
Buildings and improvements	6,535,637	5,866,477
Undeveloped land and construction in progress	1,938,923	2,296,130
Total real estate assets held for investment	10,086,784	9,628,773
Accumulated depreciation and amortization	(1,744,325)	(1,561,361)
Total real estate assets held for investment, net	8,342,459	8,067,412
CASH AND CASH EQUIVALENTS (Note 4)	849,009	60,044
RESTRICTED CASH	16,300	16,300
MARKETABLE SECURITIES (Note 10)	25,073	27,098
CURRENT RECEIVABLES, NET	16,083	26,489
DEFERRED RENT RECEIVABLES, NET	375,939	337,937
DEFERRED LEASING COSTS AND ACQUISITION-RELATED INTANGIBLE ASSETS, NET	208,306	212,805
RIGHT OF USE GROUND LEASE ASSETS (Note 9)	95,733	96,348
PREPAID EXPENSES AND OTHER ASSETS, NET (Note 2)	55,706	55,661
TOTAL ASSETS	9,984,608	8,900,094
LIABILITIES:
Secured debt, net (Notes 3 and 10)	254,854	258,593
Unsecured debt, net (Notes 3, and 10)	3,668,976	3,049,185
Unsecured line of credit (Notes 3 and 10)	0	245,000
Accounts payable, accrued expenses and other liabilities	458,421	418,848
Ground lease liabilities (Note 9)	97,936	98,400
Accrued dividends and distributions (Note 15)	59,416	53,219
Deferred revenue and acquisition-related intangible liabilities, net	131,558	139,488
Rents received in advance and tenant security deposits	61,483	66,503
Total liabilities	4,732,644	4,329,236
COMMITMENTS AND CONTINGENCIES (Note 9)
Noncontrolling Interests (Notes 1 and 5):
Common units, 115,247,221 and 106,016,287 held by the general partner and 1,931,574 and 2,023,287 held by common limited partners issued and outstanding, respectively (Note 6)	5,051,368	4,369,758
Noncontrolling interests in consolidated property partnerships and subsidiaries (Note 1)	200,596	201,100
Total capital	5,251,964	4,570,858
TOTAL LIABILITIES AND EQUITY (CAPITAL)	$ 9,984,608	$ 8,900,094