Organization, Ownership and Basis of Presentation - Narrative (Details) $ in Thousands				9 Months Ended
	Sep. 30, 2021 USD ($) ft² a property residential_unit VIE property_partnership project building	Dec. 31, 2020 USD ($) VIE	Sep. 30, 2020	Sep. 30, 2021 USD ($) ft² a property residential_unit VIE property_partnership project building
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]
Lease-up properties occupancy percentage				95.00%
Lease-up properties occupancy duration				1 year
Assets | $	$ 10,471,517	$ 10,000,708		$ 10,471,517
Liabilities | $	4,780,879	4,723,387		4,780,879
Noncontrolling interest in VIE | $	$ 192,386	$ 197,503		$ 192,386
Washington [Member]
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]
Number of properties	1			1
San Francisco, California [Member]
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]
Number of properties | building	1			1
Development properties [Member]
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]
Number of properties	4			4
Number of property partnerships | property_partnership	3			3
Development properties [Member] | San Diego and San Francisco, California [Member]
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]
Rentable square feet | ft²	683,822			683,822
Development properties [Member] | Hollywood, California [Member]
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]
Number of residential units | residential_unit	193			193
Development properties [Member] | Washington [Member]
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]
Number of properties	1			1
Development properties [Member] | Texas [Member]
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]
Number of properties	1			1
Development properties, buildings [Member] | San Diego and San Francisco, California [Member]
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]
Number of buildings	4			4
Development sites [Member]
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]
Number of properties | project	6			6
Area of undeveloped land | a	59			59
Stabilized office properties [Member]
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]
Number of buildings	121			121
Rentable square feet | ft²	15,199,178			15,199,178
Stabilized office properties [Member] | Washington [Member]
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]
Number of properties	9			9
Properties and development projects [Member]
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]
Property ownership percentage				100.00%
Office properties owned by consolidated property partnerships [Member]
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]
Number of properties	4			4
101 First LLC and 303 Second LLC [Member]
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]
Company owned general partnership interest	56.00%			56.00%
101 First LLC and 303 Second LLC [Member] | Development properties [Member]
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]
Number of property partnerships | property_partnership	2			2
Redwood LLC [Member]
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]
Number of properties	2			2
Company owned general partnership interest	93.00%			93.00%
Operating Partnership [Member]
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]
Ownership interest (percent)	99.00%	99.00%	98.40%
Non-affiliated investors and certain of our executive officers and directors [Member] | Operating Partnership [Member]
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]
Ownership interest (percent)	1.00%	1.00%	1.60%
Variable Interest Entity, Primary Beneficiary [Member]
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]
Number of VIEs | VIE	2	2		2
Assets | $	$ 455,900	$ 469,300		$ 455,900
Liabilities | $	31,700	33,900		31,700
Variable Interest Entity, Primary Beneficiary [Member] | Real estate investment [Member]
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]
Assets | $	380,600	394,600		380,600
Variable Interest Entity, Primary Beneficiary [Member] | 101 First LLC and 303 Second LLC [Member]
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]
Noncontrolling interest in VIE | $	$ 186,900	$ 191,900		$ 186,900