Schedule III - Real Estate and Accumulated Depreciation (Details) (USD $) In Thousands, unless otherwise specified					12 Months Ended																																																																3 Months Ended		12 Months Ended
	Dec. 31, 2012 sqft		Dec. 31, 2012 Office Properties [Member] sqft		Dec. 31, 2012 Office Properties [Member] 23925 Park Sorrento, Calabasas, California [Member] sqft		Dec. 31, 2012 Office Properties [Member] 23975 Park Sorrento, Calabasas, California [Member] sqft		Dec. 31, 2012 Office Properties [Member] 24025 Park Sorrento, Calabasas, California [Member] sqft		Dec. 31, 2012 Office Properties [Member] 26541 Agoura Road, Calabasas, California [Member] sqft		Dec. 31, 2012 Office Properties [Member] 2240 E. Imperial Highway, El Segundo, California [Member] sqft		Dec. 31, 2012 Office Properties [Member] 2250 E. Imperial Highway, El Segundo, California [Member] sqft		Dec. 31, 2012 Office Properties [Member] 2260 E. Imperial Highway, El Segundo, California [Member] sqft		Dec. 31, 2012 Office Properties [Member] 909 Sepulveda Boulevard, El Segundo, California [Member] sqft		Dec. 31, 2012 Office Properties [Member] 999 Sepulveda Boulevard, El Segundo, California [Member] sqft		Dec. 31, 2012 Office Properties [Member] 3750 Kilroy Airport Way, Long Beach, California [Member] sqft		Dec. 31, 2012 Office Properties [Member] 3760 Kilroy Airport Way, Long Beach, California [Member] sqft		Dec. 31, 2012 Office Properties [Member] 3780 Kilroy Airport Way, Long Beach, California [Member] sqft		Dec. 31, 2012 Office Properties [Member] 3800 Kilroy Airport Way, Long Beach, California [Member] sqft		Dec. 31, 2012 Office Properties [Member] 3840 Kilroy Airport Way, Long Beach, California [Member] sqft		Dec. 31, 2012 Office Properties [Member] 3880 Kilroy Airport Way, Long Beach, California [Member]		Dec. 31, 2012 Office Properties [Member] 3900 Kilroy Airport Way, Long Beach, California [Member] sqft		Dec. 31, 2012 Office Properties [Member] Kilroy Airport Center, Phase IV, Long Beach, California [Member]		Dec. 31, 2012 Office Properties [Member] 12100 W. Olympic Boulevard, Los Angeles, California [Member] sqft		Dec. 31, 2012 Office Properties [Member] 12200 W. Olympic Boulevard, Los Angeles, California [Member] sqft		Dec. 31, 2012 Office Properties [Member] Olympic Blvd 12233, Los Angeles, CA [Member] sqft		Dec. 31, 2012 Office Properties [Member] 12312 W. Olympic Boulevard, Los Angeles, California [Member] sqft		Dec. 31, 2012 Office Properties [Member] 6255 Sunset Boulevard, Los Angeles, CA [Member] sqft		Dec. 31, 2012 Office Properties [Member] 1633 26th Street, Santa Monica, California [Member] sqft		Dec. 31, 2012 Office Properties [Member] 2100 Colorado Avenue, Santa Monica, California [Member] sqft		Dec. 31, 2012 Office Properties [Member] 3130 Wilshire Boulevard, Santa Monica, California [Member] sqft		Dec. 31, 2012 Office Properties [Member] 501 Santa Monica Boulevard, Santa Monica, California [Member] sqft		Dec. 31, 2012 Office Properties [Member] 2829 Townsgate Road, Thousand Oaks, California [Member] sqft		Dec. 31, 2012 Office Properties [Member] 12225 El Camino Real, Del Mar, California [Member] sqft		Dec. 31, 2012 Office Properties [Member] 12235 El Camino Real, Del Mar, California [Member] sqft		Dec. 31, 2012 Office Properties [Member] 12340 El Camino Real, Del Mar, California [Member] sqft		Dec. 31, 2012 Office Properties [Member] 12390 El Camino Real, Del Mar, California [Member] sqft		Dec. 31, 2012 Office Properties [Member] 12348 High Bluff Drive, Del Mar, California [Member] sqft		Dec. 31, 2012 Office Properties [Member] 12400 High Bluff Drive, Del Mar, California [Member] sqft		Dec. 31, 2012 Office Properties [Member] 3579 Valley Centre Drive, Del Mar, Calilfornia [Member] sqft		Dec. 31, 2012 Office Properties [Member] 3611 Valley Centre Drive, Del Mar, California [Member] sqft		Dec. 31, 2012 Office Properties [Member] 3661 Valley Centre Drive, Del Mar, California [Member] sqft		Dec. 31, 2012 Office Properties [Member] 3721 Valley Centre Drive, Del Mar, California [Member] sqft		Dec. 31, 2012 Office Properties [Member] 3811 Valley Centre Drive, Del Mar, California [Member] sqft		Dec. 31, 2012 Office Properties [Member] 6200 Greenwich Drive, Governor Park, California [Member] sqft		Dec. 31, 2012 Office Properties [Member] 6220 Greenwich Drive, Governor Park, California [Member] sqft		Dec. 31, 2012 Office Properties [Member] 15051 Avenue of Science, I-15 Corridor, California [Member] sqft		Dec. 31, 2012 Office Properties [Member] 15073 Avenue of Science, I-15 Corridor, California [Member] sqft		Dec. 31, 2012 Office Properties [Member] 15231 Avenue of Science, I-15 Corridor, California [Member] sqft		Dec. 31, 2012 Office Properties [Member] 15253 Avenue of Science, I-15 Corridor, California [Member] sqft		Dec. 31, 2012 Office Properties [Member] 15333 Avenue of Science, I-15 Corridor, California [Member] sqft		Dec. 31, 2012 Office Properties [Member] 15378 Avenue of Science, I-15 Corridor, California [Member] sqft		Dec. 31, 2012 Office Properties [Member] 15435 Innovation Drive, I-15 Corridor, California [Member] sqft		Dec. 31, 2012 Office Properties [Member] 15445 Innovation Drive, I-15 Corridor, California [Member] sqft		Dec. 31, 2012 Office Properties [Member] 13280 Evening Creek Drive, South I-15 Corridor, California [Member] sqft		Dec. 31, 2012 Office Properties [Member] 13290 Evening Creek Drive, South I-15 Corridor, California [Member] sqft		Dec. 31, 2012 Office Properties [Member] 13480 Evening Creek Drive, North I-15 Corridor, California [Member] sqft		Dec. 31, 2012 Office Properties [Member] 13500 Evening Creek Drive, North I-15 Corridor, California [Member] sqft		Dec. 31, 2012 Office Properties [Member] 13520 Evening Creek Drive, North I-15 Corridor, California [Member] sqft		Dec. 31, 2012 Office Properties [Member] 7525 Torrey Santa Fe, 56 Corridor, California [Member] sqft		Dec. 31, 2012 Office Properties [Member] 7535 Torrey Santa Fe, 56 Corridor, California [Member] sqft		Dec. 31, 2012 Office Properties [Member] 7545 Torrey Santa Fe, 56 Corridor, California [Member] sqft		Dec. 31, 2012 Office Properties [Member] 7555 Torrey Santa Fe, 56 Corridor, California [Member] sqft		Dec. 31, 2012 Office Properties [Member] 2355 Northside Drive, Mission Valley, California [Member] sqft		Dec. 31, 2012 Office Properties [Member] 2365 Northside Drive, Mission Valley, California [Member] sqft		Dec. 31, 2012 Office Properties [Member] 2375 Northside Drive, Mission Valley, California [Member] sqft		Dec. 31, 2012 Office Properties [Member] 2385 Northside Drive, Mission Valley, California [Member] sqft		Dec. 31, 2012 Office Properties [Member] 2305 Historic Decatur Road, San Diego, California [Member] sqft		Dec. 31, 2012 Office Properties [Member] 10020 Pacific Mesa Boulevard, Sorrento Mesa, California [Member] sqft		Dec. 31, 2012 Office Properties [Member] 4910 Directors Place, Sorrento Mesa, California [Member] sqft		Dec. 31, 2012 Office Properties [Member] 4921 Directors Place, Sorrento Mesa, California [Member] sqft		Dec. 31, 2012 Office Properties [Member] 4939 Directors Place, Sorrento Mesa, California [Member] sqft		Dec. 31, 2012 Office Properties [Member] 4955 Directors Place, Sorrento Mesa, California [Member] sqft		Dec. 31, 2012 Office Properties [Member] 5005 Wateridge Vista Drive, Sorrento Mesa, California [Member] sqft		Dec. 31, 2012 Office Properties [Member] 5010 Wateridge Vista Drive, Sorrento Mesa, California [Member] sqft		Dec. 31, 2012 Office Properties [Member] 10770 Wateridge Circle, San Diego, California [Member] sqft		Dec. 31, 2012 Office Properties [Member] 6055 Lusk Avenue, Sorrento Mesa, California [Member] sqft		Dec. 31, 2012 Office Properties [Member] 6260 Sequence Drive, Sorrento Mesa, California [Member] sqft		Dec. 31, 2012 Office Properties [Member] 6290 Sequence Drive, Sorrento Mesa, California [Member] sqft		Dec. 31, 2012 Office Properties [Member] 6310 Sequence Drive, Sorrento Mesa, California [Member] sqft		Dec. 31, 2012 Office Properties [Member] 6340 Sequence Drive, Sorrento Mesa, California [Member] sqft		Dec. 31, 2012 Office Properties [Member] 6350 Sequence Drive, Sorrento Mesa, California [Member] sqft		Dec. 31, 2012 Office Properties [Member] 10390 Pacific Center Court, Sorrento Mesa, California [Member] sqft		Dec. 31, 2012 Office Properties [Member] 10394 Pacific Center Court, Sorrento Mesa, California [Member] sqft		Dec. 31, 2012 Office Properties [Member] 10398 Pacific Center Court, Sorrento Mesa, California [Member] sqft		Dec. 31, 2012 Office Properties [Member] 10421 Pacific Center Court, Sorrento Mesa, California [Member] sqft		Dec. 31, 2012 Office Properties [Member] 10445 Pacific Center Court, Sorrento Mesa, California [Member] sqft		Dec. 31, 2012 Office Properties [Member] 10455 Pacific Center Court, Sorrento Mesa, California [Member] sqft		Dec. 31, 2012 Office Properties [Member] 5717 Pacific Center Boulevard, Sorrento Mesa, California [Member] sqft		Dec. 31, 2012 Office Properties [Member] 4690 Executive Drive, UTC, California [Member] sqft		Dec. 31, 2012 Office Properties [Member] 9785 Towne Center Drive, UTC, California [Member] sqft		Dec. 31, 2012 Office Properties [Member] 9791 Towne Center Drive, UTC, California [Member] sqft		Dec. 31, 2012 Office Properties [Member] 8101 Kaiser Boulevard, Anaheim, California [Member] sqft		Dec. 31, 2012 Office Properties [Member] 2211 Michelson Drive, Irvine, California [Member] sqft		Dec. 31, 2012 Office Properties [Member] 111 Pacifica, Irvine, California [Member] sqft		Dec. 31, 2012 Office Properties [Member] 999 Town and Country, Orange, California [Member] sqft		Dec. 31, 2012 Office Properties [Member] Bohannon Drive 4100, Menlo Park, CA [Member] sqft		Dec. 31, 2012 Office Properties [Member] Bohannon Drive 4200, Menlo Park, CA [Member] sqft		Dec. 31, 2012 Office Properties [Member] Bohannon Drive 4300, Menlo Park, CA [Member] sqft		Dec. 31, 2012 Office Properties [Member] Bohannon Drive 4400, Menlo Park, CA [Member] sqft		Dec. 31, 2012 Office Properties [Member] Bohannon Drive 4500, Menlo Park, CA [Member] sqft		Dec. 31, 2012 Office Properties [Member] Bohannon Drive 4600, Menlo Park, CA [Member] sqft		Dec. 31, 2012 Office Properties [Member] Bohannon Drive 4700, Menlo Park, CA [Member] sqft		Dec. 31, 2012 Office Properties [Member] 303 Second Street, San Francisco, California [Member] sqft		Dec. 31, 2012 Office Properties [Member] 100 First Street, San Francisco, California [Member] sqft		Dec. 31, 2012 Office Properties [Member] 250 Brannan Street, San Francisco, California [Member] sqft		Dec. 31, 2012 Office Properties [Member] 201 Third Street, San Francisco, California [Member] sqft		Dec. 31, 2012 Office Properties [Member] 301 Brannan Street, San Francisco, California [Member] sqft		Dec. 31, 2012 Office Properties [Member] 370 Third Street, San Francisco, California [Member]		Dec. 31, 2012 Office Properties [Member] 4040 Civic Center Drive, San Rafael, California [Member] sqft		Dec. 31, 2012 Office Properties [Member] N. Mathilda Avenue 599, Sunnyvale, CA [Member] sqft		Dec. 31, 2012 Office Properties [Member] 601 108th Avenue, Bellevue, Washington [Member] sqft		Dec. 31, 2012 Office Properties [Member] NE 4th Street 10900 Bellevue, Washington [Member] sqft		Dec. 31, 2012 Office Properties [Member] 10220 NE Points Drive, Kirkland, Washington [Member] sqft		Dec. 31, 2012 Office Properties [Member] 10230 NE Points Drive, Kirkland, Washington [Member] sqft		Dec. 31, 2012 Office Properties [Member] 10210 NE Points Drive, Kirkland, Washington [Member] sqft		Dec. 31, 2012 Office Properties [Member] 3933 Lake Washington Boulevard NE, Kirkland, Washington [Member] sqft		Dec. 31, 2012 Office Properties [Member] 15050 N.E. 36th Street, Redmond, Washington [Member] sqft		Dec. 31, 2012 Office Properties [Member] Fremont Lake View Seattle WA [Member] sqft		Dec. 31, 2012 Office Properties [Member] N 34th Street 701, Lake Union, Washington [Member] sqft		Dec. 31, 2012 Office Properties [Member] N 34th Street 801, Lake Union, Washington [Member] sqft		Dec. 31, 2012 Office Properties [Member] 17150 Von Karman, Irvine, California [Member] sqft		Dec. 31, 2012 Undeveloped Land and CIP Properties [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Amount of Encumbrances	$ 553,919		$ 551,402		$ 11,210	[1]													$ 68,615	[2]																							$ 40,523				$ 53,554				$ 97,000																					[3]								[4]																																																																																																																							$ 135,000	[5]																	$ 83,116	[6]	$ 28,384	[6]											$ 34,000	[6]					$ 2,517
Real Estate and Accumulated Depreciation, Initial Cost of Land	1,109,020		587,387		50		765		845		1,979		1,044		2,579		2,518		3,577		1,407																		352		4,329		22,100		3,325		18,111		2,080		5,474		8,921		4,547		5,248		1,700		1,507		4,201		3,453		1,629		15,167		2,167		4,184		4,038		4,297		3,452		1,583		3,213		2,888		2,070		2,233		1,548		2,371		3,565		2,143		2,143		3,701		5,229		7,997		7,581		7,581		2,348		2,950		2,950		2,287		4,066		7,359		3,947		2,752		5,240		8,007		2,240		3,792		2,225		2,521		3,320		3,786		4,560		3,935		3,206		2,403		2,940		2,434		4,941		3,267		2,696		1,947		2,926		2,247		4,044		2,693		1,623		2,722		1,814		2,369		9,319		5,165		7,867		4,835		4,798		6,527		4,798		6,527		4,798		6,527		63,550		49,150		7,630		19,260		5,910				10,210		13,538		0		25,080		2,554		5,071		4,336		2,380		9,260		0		0		0		4,848		521,633
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements	2,734,988		2,644,476		2,346		17,720		15,896		9,630		11,763		29,062		28,370		34,042		34,326		1,941		17,467		22,319		19,408		13,586		9,704		12,615				45,611		35,488		53,170		12,202		60,320		6,672		26,087		6,579		12,044		8,001		9,633		8,543		13,896		11,981		3,096		40,497		6,897		19,352		21,144		18,967		16,152		5,235		10,628		5,780		5,728		8,830		6,423		16,500		3,796		6,311		6,311		8,398		11,871				35,903		35,903		28,035		33,808		33,708		24,916		8,332		15,257		8,146		14,513		22,220		52,189		13,039		11,091		12,698		14,122		5,049		10,767		26,671		8,008		9,803		7,349		4,946		7,302		14,824		5,779		7,134		5,152		7,979		5,945		10,701		6,280		7,926		9,932		6,622		6,180		82,836		4,653		9,579		15,526		15,406		20,958		15,406		20,957		15,406		20,958		154,153		131,238		22,770		84,018		22,450				18,029		12,559		214,095		150,877		12,080		24,694		24,187		15,114		34,650		37,404		48,027		58,537		7,342		90,512
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements	913,386		715,877		304		5,370		3,716		9,798		23,715		23,009		19,134		39,782		10,995		10,248		8,196		14,561		16,641		10,353		5,676		8,264		2,087	[7]	15,401		15,145		428		714		3,948		3,147		13,114		10,413		6,427		5,585		2,992		4,495		7,369		1,263		3,451		11,609		6,777		15,868		8,803		5,692		20,076		2,752		16,371		5,769		1,648		4,888		1,571		3,424		3,156		2,612		5,146		2,937		1,458		41,733		11,338		12,376		4,060		5,991		8,117		3,712		706		(83)		188		3,738		435		15,348		6,548		4,748		4,359		3,696		2,026		27,132		184		5,919		1,291		4,906		190		9,963		(4,387)		7,500		(782)		1,316		21,999		567		(2,251)		4,219		2,394		(1,077)		1,121		2,091		1,507		4,254		219		(18)		(413)		268		551		1,041		67		821		18,442		11,188		1,252		13,803		1,008		13,749		396		0		1,222		1,665		402		2,669		892		990		197		352		(140)		(360)		2,224		197,509
Real Estate and Accumulated Depreciation, Carrying Amount of Land	1,134,347		612,714		50		765		845		1,979		1,048		2,547		2,547		3,577		1,407																		9,633		3,977		22,100		3,399		18,111		2,040		5,476		9,188		4,551		5,248		1,683		1,530		4,201		3,453		1,629		15,167		2,858		5,259		4,725		4,254		4,457		1,722		3,426		2,888		2,070		2,233		1,548		2,371		3,565		2,046		2,046		3,701		5,229		7,997		7,580		7,580		2,348		2,950		2,950		2,287		3,270		5,919		3,175		5,759		5,240		8,007		2,240		3,792		2,198		3,179		3,320		15,620		4,560		3,942		3,212		2,407		2,941		2,464		4,922		3,267		1,671		1,222		2,926		1,809		3,780		2,693		1,623		2,329		2,217		2,377		9,319		5,166		7,867		4,835		4,798		6,527		4,798		6,527		4,798		6,527		63,550		49,150		7,630		19,260		5,910		0		10,210		13,538		0		25,080		2,554		5,071		4,336		2,380		9,260		0		0		0		7,301		521,633
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements	3,623,047		3,335,026		2,650		23,090		19,612		19,428		35,474		52,103		47,475		73,824		45,321		12,189		25,663		36,880		36,049		23,939		15,380		20,879		2,087	[7]	51,731		50,985		53,598		12,842		64,268		9,859		39,199		16,725		18,467		13,586		12,642		13,015		21,265		13,244		6,547		52,106		12,983		34,145		29,260		24,702		35,223		7,848		26,786		11,549		7,376		13,718		7,994		19,924		6,952		9,020		11,554		11,335		13,329		41,733		47,242		48,280		32,095		39,799		41,825		28,628		9,834		16,614		9,106		15,244		22,655		67,537		19,587		15,839		17,084		17,160		7,075		26,065		26,855		13,920		11,088		12,251		5,135		17,235		10,456		13,279		7,377		7,193		29,978		6,950		8,714		10,499		10,320		9,248		7,340		8,263		84,343		8,906		9,798		15,508		14,993		21,226		15,957		21,998		15,473		21,779		172,595		142,426		24,022		97,821		23,458		13,749		18,425		12,559		215,317		152,542		12,482		27,363		25,079		16,104		34,847		37,756		47,887		58,177		7,113		288,021
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements	4,757,394		3,947,740		2,700	[1]	23,855	[1]	20,457	[1]	21,407		36,522		54,650		50,022		77,401	[2]	46,728	[2]	12,189		25,663		36,880		36,049		23,939		15,380		20,879		2,087	[7]	61,364		54,962		75,698		16,241		82,379		11,899		44,675		25,913		23,018		18,834		14,325		14,545		25,466	[2]	16,697	[2]	8,176		67,273		15,841	[3]	39,404	[3]	33,985	[3]	28,956	[3]	39,680	[4]	9,570		30,212		14,437		9,446		15,951		9,542		22,295		10,517		11,066		13,600		15,036		18,558		49,730		54,822		55,860		34,443		42,749		44,775		30,915		13,104		22,533		12,281		21,003		27,895		75,544		21,827		19,631		19,282		20,339		10,395		41,685		31,415		17,862		14,300		14,658		8,076		19,699		15,378		16,546		9,048		8,415		32,904		8,759		12,494		13,192		11,943	[2]	11,577		9,557		10,640		93,662		14,072		17,665		20,343		19,791		27,753		20,755		28,525		20,271		28,306		236,145	[5]	191,576		31,652		117,081		29,368		13,749		28,635		26,097		215,317		177,622	[6]	15,036	[6]	32,434	[6]	29,415	[6]	18,484	[6]	44,107		37,756		47,887		58,177		14,414		809,654
Real Estate and Accumulated Depreciation, Accumulated Depreciation	$ 756,515		$ 756,515		$ 1,293		$ 10,909		$ 9,913		$ 9,765		$ 17,379		$ 40,489		$ 895		$ 20,802		$ 13,604		$ 8,305		$ 19,147		$ 29,000		$ 18,072		$ 12,394		$ 225		$ 10,966		$ 2,087	[7]	$ 15,325		$ 26,198		$ 415		$ 5,703		$ 1,380		$ 4,889		$ 13,927		$ 9,513		$ 9,456		$ 7,221		$ 4,943		$ 6,375		$ 6,809		$ 6,840		$ 4,413		$ 16,183		$ 5,668		$ 15,193		$ 13,437		$ 7,612		$ 13,717		$ 4,802		$ 8,122		$ 5,119		$ 3,543		$ 3,993		$ 1,998		$ 3,881		$ 3,141		$ 4,494		$ 5,521		$ 1,733		$ 1,593		$ 6,852		$ 11,744		$ 12,818		$ 6,488		$ 8,306		$ 9,330		$ 5,757		$ 1,279		$ 1,874		$ 1,172		$ 1,757		$ 1,621		$ 14,967		$ 1,906		$ 2,121		$ 7,021		$ 10,400		$ 3,193		$ 172		$ 3,307		$ 6,209		$ 5,205		$ 6,204		$ 2,689		$ 8,245		$ 5,633		$ 4,481		$ 3,217		$ 2,824		$ 11,682		$ 2,911		$ 3,684		$ 2,721		$ 5,009		$ 3,633		$ 2,883		$ 4,342		$ 7,926		$ 4,975		$ 1,110		$ 457		$ 446		$ 589		$ 451		$ 655		$ 363		$ 636		$ 17,837		$ 11,851		$ 2,215		$ 7,397		$ 1,065		$ 923		$ 1,262		$ 0		$ 13,857		$ 2,526		$ 830		$ 1,728		$ 1,583		$ 958		$ 2,404		$ 888		$ 1,172		$ 1,239		$ 7,113		$ 0
Real Estate and Accumulated Depreciation, Life Used for Depreciation					35 years	[8]	35 years	[8]	35 years	[8]	35 years	[8]	35 years	[8]	35 years	[8]	35 years	[8]	35 years	[8]	35 years	[8]	35 years	[8]	35 years	[8]	35 years	[8]	35 years	[8]	35 years	[8]	35 years	[8]	35 years	[8]	35 years	[8]	35 years	[8]	35 years	[8]	35 years	[8]	35 years	[8]	35 years	[8]	35 years	[8]	35 years	[8]	35 years	[8]	35 years	[8]	35 years	[8]	35 years	[8]	35 years	[8]	35 years	[8]	35 years	[8]	35 years	[8]	35 years	[8]	35 years	[8]	35 years	[8]	35 years	[8]	35 years	[8]	35 years	[8]	35 years	[8]	35 years	[8]	35 years	[8]	35 years	[8]	35 years	[8]	35 years	[8]	35 years	[8]	35 years	[8]	35 years	[8]	35 years	[8]	35 years	[8]	35 years	[8]	35 years	[8]	35 years	[8]	35 years	[8]	35 years	[8]	35 years	[8]	35 years	[8]	35 years	[8]	35 years	[8]	35 years	[8]	35 years	[8]	35 years	[8]	35 years	[8]	35 years	[8]	35 years	[8]	35 years	[8]	35 years	[8]	35 years	[8]	35 years	[8]	35 years	[8]	35 years	[8]	35 years	[8]	35 years	[8]	35 years	[8]	35 years	[8]	35 years	[8]	35 years	[8]	35 years	[8]	35 years	[8]	35 years	[8]	35 years	[8]	35 years	[8]	35 years	[8]	35 years	[8]	35 years	[8]	35 years	[8]	35 years	[8]	35 years	[8]	35 years	[8]	35 years	[8]	35 years	[8]	35 years	[8]	35 years	[8]	35 years	[8]	35 years	[8]	35 years	[8]	35 years	[8]	35 years	[8]	35 years	[8]	35 years	[8]	35 years	[8]	35 years	[8]	35 years	[8]	35 years	[8]	35 years	[8]	35 years	[8]	35 years	[8]	35 years	[8]	35 years	[8]	35 years	[8]	35 years	[8]	35 years	[8]	35 years	[8]	35 years	[8]	35 years	[8]	35 years	[8]	35 years	[8]
Rentable square feet	13,249,780	[9]	13,249,780	[9]	11,789	[9]	100,592	[9]	102,264	[9]	90,156	[9]	122,870	[9]	298,728	[9]	298,728	[9]	241,607	[9]	128,504	[9]	10,457	[9]	165,278	[9]	219,745	[9]	192,476	[9]	136,026	[9]			126,840	[9]			150,167	[9]	150,302	[9]	151,029	[9]	78,000	[9]	321,883	[9]	44,915	[9]	102,864	[9]	88,339	[9]	73,115	[9]	81,067	[9]	60,148	[9]	54,673	[9]	87,405	[9]	72,332	[9]	38,710	[9]	208,464	[9]	52,375	[9]	130,178	[9]	129,752	[9]	114,780	[9]	112,067	[9]	71,000	[9]	141,214	[9]	70,617	[9]	46,759	[9]	65,638	[9]	37,437	[9]	78,880	[9]	68,910	[9]	49,863	[9]	51,500	[9]	41,665	[9]	61,176	[9]	149,817	[9]	147,533	[9]	141,129	[9]	103,979	[9]	130,243	[9]	130,354	[9]	101,236	[9]	53,610	[9]	91,260	[9]	51,516	[9]	88,795	[9]	103,900	[9]	318,000	[9]	50,925	[9]	56,136	[9]	60,662	[9]	76,246	[9]	61,460	[9]	111,318	[9]	174,310	[9]	93,000	[9]	130,536	[9]	90,000	[9]	62,415	[9]	66,400	[9]	132,600	[9]	68,400	[9]	59,630	[9]	43,645	[9]	75,899	[9]	48,709	[9]	90,000	[9]	67,995	[9]	47,212	[9]	75,534	[9]	50,466	[9]	59,790	[9]	271,556	[9]	67,496	[9]	98,551	[9]	46,614	[9]	46,255	[9]	62,920	[9]	46,255	[9]	62,920	[9]	46,255	[9]	62,920	[9]	740,047	[9]	466,490	[9]	92,948	[9]	332,893	[9]	74,430	[9]			130,237	[9]	75,810	[9]	488,470	[9]	416,755	[9]	49,851	[9]	98,982	[9]	84,641	[9]	46,450	[9]	122,103	[9]	111,580	[9]	138,995	[9]	169,412	[9]	(16)	[9]

[1] These properties secure a $11.2 million mortgage note.

[2] These properties secure a $68.6 million mortgage note.

[3] This property secures a $40.5 million mortgage note.

[4] This property secures a $53.6 million mortgage note.

[5] These properties secure a $97.0 million mortgage note.

[6] This property secures a $135.0 million mortgage note.

[7] These costs represent infrastructure costs incurred in 1989. During the third quarter of 2009, we exercised our option to terminate the ground lease at Kilroy Airport Center, Phase IV in Long Beach, California. We had previously leased this land, which is adjacent to our Office Properties at Kilroy Airport Center, Long Beach, for potential future development opportunities.

[8] The initial costs of buildings are depreciated over 35 years using a straight-line method of accounting; improvements capitalized subsequent to acquisition are depreciated over the shorter of the lease term or useful life, generally ranging from one to 20 years.

[9] Includes square footage from our stabilized portfolio.