Property Dispositions (Detail) (USD $) In Millions, unless otherwise specified	9 Months Ended	0 Months Ended
	Sep. 30, 2014	Jun. 11, 2014 Property	Oct. 17, 2014 Property	Dec. 31, 2013 Property
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of real estate properties, held for sale	71			1
2014 Property Dispositions [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Aggregate gross sales price	$ 158.6
Multi Tenant Portfolio [Member] | ARC Properties Operating Partnership, L.P. [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of real estate properties disposed of		9
Number of multi tenant properties sold		67
Multi Tenant Portfolio [Member] | ARC Properties Operating Partnership, L.P. [Member] | Subsequent Event [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of real estate properties disposed of			64
Single Tenant Properties [Member] | ARC Properties Operating Partnership, L.P. [Member] | Subsequent Event [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of real estate properties disposed of			7
Single Tenant Properties [Member] | 2014 Property Dispositions [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of real estate properties disposed of	29
Multi Tenant Properties [Member] | 2014 Property Dispositions [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of real estate properties disposed of	1