Rent and Tenant Receivables and Other Assets, Net (Details) - USD ($)	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Dec. 31, 2018
Property, Plant and Equipment [Line Items]
Straight-line rent receivable, net	$ 265,464,000		$ 259,106,000
Accounts receivable, net	44,244,000		36,939,000
Deferred costs, net	12,473,000		17,515,000
Investment in direct financing leases, net	10,735,000		13,254,000
Prepaid expenses	8,418,000		5,022,000
Leasehold improvements, property and equipment, net	5,133,000		9,754,000
Other assets, net	7,622,000		16,658,000
Total	361,641,000		366,092,000
Property and equipment disposed of	4,100,000
Leasehold Improvements [Member]
Property, Plant and Equipment [Line Items]
Amortization expense	300,000	$ 300,000
Write off of leasehold	0	0
Accumulated amortization	2,700,000		5,900,000
Property and Equipment [Member]
Property, Plant and Equipment [Line Items]
Accumulated amortization	4,600,000		7,000,000.0
Depreciation expense	400,000	500,000
Line of Credit [Member]
Property, Plant and Equipment [Line Items]
Amortization expense	1,100,000	2,600,000
Accumulated amortization for deferred costs	48,700,000		47,600,000
Rent Receivables [Member]
Property, Plant and Equipment [Line Items]
Allowance for doubtful accounts			1,000,000.0
Accounts Receivable [Member]
Property, Plant and Equipment [Line Items]
Allowance for doubtful accounts			5,300,000
Cole Real Estate Investments, Inc. [Member]
Property, Plant and Equipment [Line Items]
Other Investments	7,552,000		$ 7,844,000
Maximum [Member]
Property, Plant and Equipment [Line Items]
Write off of depreciation	$ 100,000	$ 0