Dispositions and Discontinued Operations - Summary of the Properties Sold (Detail) $ in Thousands	12 Months Ended
	Dec. 31, 2016 USD ($) ft²	Dec. 31, 2015 USD ($) a	Dec. 31, 2014 USD ($) ft²
Property Dispositions [Line Items]
Rentable Square Feet	3,372,794	2,129,753
Gain (Loss) Recorded	$ 0	$ 0	$ 2,125
Gain (loss) on sale of real estate	$ 17,377	$ 0	$ (150)
6010 N Paramount Boulevard [Member]
Property Dispositions [Line Items]
Rentable Square Feet | ft²	16,534
Contractual Sales Price	$ 2,480
Gain (Loss) Recorded	$ 944
1840 Dana Street [Member]
Property Dispositions [Line Items]
Rentable Square Feet | ft²	13,497
Contractual Sales Price	$ 4,250
Gain (Loss) Recorded	$ 1,445
East Mulberry Dr [Member]
Property Dispositions [Line Items]
Rentable Square Feet | ft²	153,080
Contractual Sales Price	$ 15,000
Gain (Loss) Recorded	$ (9,174)
La Palma Ave [Member]
Property Dispositions [Line Items]
Rentable Square Feet | ft²	115,760
Contractual Sales Price	$ 17,000
Gain (Loss) Recorded	$ (4,752)
331 East 157th Street [Domain]
Property Dispositions [Line Items]
Rentable Square Feet | ft²	12,000
Contractual Sales Price	$ 1,975
Gain (Loss) Recorded	$ (1,062)
Park Center Drive
Property Dispositions [Line Items]
Rentable Square Feet | ft²			124,997
Contractual Sales Price			$ 10,103
Gain (Loss) Recorded			$ 2,262
N. Madera Road
Property Dispositions [Line Items]
Rentable Square Feet | ft²			63,305
Contractual Sales Price			$ 4,350
Gain (Loss) Recorded			$ (137)
Zenith Drive
Property Dispositions [Line Items]
Rentable Square Feet | ft²			37,992
Contractual Sales Price			$ 1,822
Gain (loss) on sale of real estate			$ (150)