Sales of Assets (Details)				3 Months Ended	6 Months Ended
	Oct. 31, 2016 USD ($)	Sep. 30, 2016 USD ($)	Jul. 15, 2016 USD ($) a ft²	Dec. 31, 2017 USD ($)	Dec. 31, 2017 USD ($)	Dec. 31, 2016 USD ($)
Torrance California [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Area of Real Estate Property | ft²			665,000
Area of land (in acres) | a			20.3
Proceeds From Sale of Property Held-for-Sale, Gross			$ 43,000,000
Proceeds from sale of property held-for-sale			$ 42,500,000
Monthly base rent	$ 100,000
Gain (Loss) on Sale of Properties				$ 37,400,000	$ 37,400,000	$ 37,400,000
Sale Leaseback Transaction, Accrued Interest						700,000
Sale Leaseback Transaction, Rent Expense						1,400,000
N. California [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Proceeds From Sale of Property Held-for-Sale, Gross		$ 2,200,000
Monthly base rent		$ 10,000
Gain (Loss) on Sale of Properties						$ 2,000,000