Dispositions (Details) $ in Thousands		3 Months Ended
		Mar. 31, 2016 USD ($) ft² a property	Mar. 31, 2015 USD ($)
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Gain on sale of land		$ 0	$ 17,268
Torrey Santa Fe Properties [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of Buildings | property	[1]	4
Rentable Square Feet | ft²	[1]	465,812
Sales prices	[1],[2]	$ 262,300
Gain on sale of land		146,000
Torrey Santa Fe Properties [Member] | Restricted cash [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Sales prices		258,100
Carlsbad, California Land Parcel [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Sales prices		$ 4,500
Area of land sold | a		7.6

[1] Represents gross sales price before the impact of broker commissions and closing costs.

[2] The Torrey Santa Fe Properties include the following: 7525 Torrey Santa Fe, 7535 Torrey Santa Fe, 7545 Torrey Santa Fe, and 7555 Torrey Santa Fe.