Acquisitions (Details Textuals) (USD $)	9 Months Ended									9 Months Ended			9 Months Ended		1 Months Ended
	Sep. 30, 2013 building sqft	Sep. 30, 2013 In-Place Leases [Member]	Sep. 30, 2013 Above-Market Leases [Member]	Sep. 30, 2013 Deferred Leasing Costs [Member]	Sep. 30, 2013 6.05% Mortgage Payable Due June 1, 2019 [Member] Kilroy Realty, L.P. [Member] Secured Debt [Member]	Sep. 30, 2013 Office Properties Acquisitions [Member] building		Sep. 30, 2013 320 & 321 Westlake Terry, Seattle WA [Member] building		Sep. 30, 2013 12780 and 12790 El Camino Real, Sandiego, CA [Member] acre building		Jun. 27, 2013 Redwood City Partners, LLC [Member] acre sqft	Sep. 30, 2013 Purchase Price Of Business Combination [Member] Assets, Total [Member] Office Properties Acquisitions [Member]	Sep. 30, 2013 Purchase Price Of Business Combination [Member] Assets, Total [Member] 320 & 321 Westlake Terry, Seattle WA [Member]	Oct. 29, 2013 Subsequent Event [Member] acre
Business Acquisition [Line Items]
Number of buildings	14					4		2	[1],[2]	2	[3]
Concentration risk, percentage													10.00%	5.00%
Principal amount of secured debt					$ 83,900,000
Debt premium					11,600,000
Deferred leasing costs and acquisition-related intangible assets		19,600,000	3,200,000	7,900,000		30,789,000	[4],[5]
Weighted average amortization period in years for deferred leasing and acquisition-related intangible assets		4 years 8 months 0 days	6 years 1 month 0 days	5 years 11 months 0 days
Below Market Lease, Acquired	4,200,000
Weighted average amortization period in years for acquisition-related liabilities	7 years 8 months 0 days
Area of real estate property	1,159,185											300,000
Payments to acquire land										$ 9,400,000					$ 17,000,000
Area of land										4.2		0.35			2.0

[1] We acquired these properties through a new special purpose entity wholly owned by the Finance Partnership.

[2] In connection with this acquisition, we assumed secured debt with an outstanding principal balance of $83.9 million that was recorded at fair value on the acquisition date, resulting in a premium of approximately $11.6 million (see Note 5).

[3] As of September 30, 2013, these properties, together the “Heights of Del Mar” project, are temporarily being held in a separate VIE to facilitate potential Section 1031 Exchanges (see Note 1). The $126.4 million purchase price includes $9.4 million for 4.2 acres of undeveloped land the Company acquired in connection with this acquisition.

[4] The purchase price of the two acquisitions completed during the nine months ended September 30, 2013 were individually less than 5% and in aggregate less than 10% of the Company’s total assets as of September 30, 2013.

[5] Represents in-place leases (approximately $19.6 million with a weighted average amortization period of 4.7 years), above-market leases (approximately $3.2 million with a weighted average amortization period of 6.1 years), and leasing commissions (approximately $7.9 million with a weighted average amortization period of 5.9 years).