Related Party Transactions and Arrangements (Details) - USD ($)		12 Months Ended
	Feb. 01, 2018	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Related Party Transaction [Line Items]
Equity in income and gain on disposition of unconsolidated entities		$ 3,539,000	$ 2,618,000	$ 1,869,000
Aggregate equity investments		7,255,000	7,552,000
Unrealized gain (loss) included in other comprehensive income, net		297,000	292,000
CCIT II and CMFT [Member]
Related Party Transaction [Line Items]
Equity in income and gain on disposition of unconsolidated entities	$ 600,000
Aggregate equity investments		7,300,000	7,600,000
Unrealized gain (loss) included in other comprehensive income, net		(300,000)	(300,000)
Gain included in other income, net				5,100,000
Cole Real Estate Investments, Inc. [Member]
Related Party Transaction [Line Items]
Property management fee revenue		$ 0	$ 0	$ 8,000,000.0