Schedule III - Real Estate and Accumulated Depreciation (Details) (Textuals) $ in Thousands	12 Months Ended
Dec. 31, 2016 USD ($) ft²	Jan. 31, 2014 ft²
Real Estate and Accumulated Depreciation [Line Items]
Real estate and accumulated depreciation, amount of encumbrances	$ 469,766
Rentable Square Feet (unaudited) \| ft²	14,025,856	79,000
Debt premium	$ 4,400
Amortization of debt issuance costs	1,400
Aggregate cost of property for federal income tax purposes	$ 5,900,000
Building [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real estate and accumulated depreciation, life used for depreciation	35 years
Tenant Improvements [Member] \| Minimum [Member]
Real Estate and Accumulated Depreciation [Line Items]
Property depreciable lives	1 year
Tenant Improvements [Member] \| Maximum [Member]
Real Estate and Accumulated Depreciation [Line Items]
Property depreciable lives	20 years
Office Building [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real estate and accumulated depreciation, amount of encumbrances	$ 469,766
Rentable Square Feet (unaudited) \| ft²	14,025,856
23925 Park Sorrento, Calabasas, California [Member] \| Office Building [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real estate and accumulated depreciation, life used for depreciation	35 years
Real estate and accumulated depreciation, amount of encumbrances	$ 1,215
Rentable Square Feet (unaudited) \| ft²	11,789
12100 W. Olympic Boulevard, Los Angeles, California [Member] \| Office Building [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real estate and accumulated depreciation, life used for depreciation	35 years
Real estate and accumulated depreciation, amount of encumbrances	$ 170,000
Rentable Square Feet (unaudited) \| ft²	152,048
909 Sepulveda Boulevard, El Segundo, California [Member] \| Office Building [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real estate and accumulated depreciation, life used for depreciation	35 years
Real estate and accumulated depreciation, amount of encumbrances
Rentable Square Feet (unaudited) \| ft²	244,136
2100 Colorado Avenue, Santa Monica, California [Member] \| Office Building [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real estate and accumulated depreciation, life used for depreciation	35 years
Real estate and accumulated depreciation, amount of encumbrances	$ 94,754
Rentable Square Feet (unaudited) \| ft²	102,864
303 Second Street, San Francisco, California [Member] \| Office Building [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real estate and accumulated depreciation, life used for depreciation	35 years
Real estate and accumulated depreciation, amount of encumbrances	$ 125,756
Rentable Square Feet (unaudited) \| ft²	740,047
320 Westlake Avenue North, WA [Member] \| Office Building [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real estate and accumulated depreciation, life used for depreciation	35 years
Real estate and accumulated depreciation, amount of encumbrances	$ 78,041
Rentable Square Feet (unaudited) \| ft²	184,643
Lease up properties [Member]
Real Estate and Accumulated Depreciation [Line Items]
Rentable Square Feet (unaudited) \| ft²	377,000
Variable Interest Entity
Real Estate and Accumulated Depreciation [Line Items]
Gross costs attributable to properties held	$ 200,000

Amount of amortization expense attributable to debt issuance costs.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 45
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Amount, after accumulated amortization, of debt premium.

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Net rentable area for properties owned.

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Cost basis of real estate investments for federal income tax purposes for entities with a substantial portion of business acquiring and holding investment real estate.

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