Related Party Transactions and Arrangements - Revenue from Cole REITs (Details) - USD ($) $ in Thousands		12 Months Ended
	Jan. 29, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Related Party Transaction [Line Items]
Related-party revenues		$ 118,423	$ 110,809	$ 202,434
Affiliated Entity [Member] | Revolving Credit Facility [Member] | Credit Facility [Member]
Related Party Transaction [Line Items]
Interest income		453	1,275	307
Offering-related fees and reimbursements [Member]
Related Party Transaction [Line Items]
Related-party revenues		36,533	24,410	87,109
Selling commissions [Member]
Related Party Transaction [Line Items]
Related-party revenues		19,943	14,101	57,023
Dealer manager and distribution fees [Member]
Related Party Transaction [Line Items]
Related-party revenues		8,307	5,131	17,533
Reimbursement revenue [Member]
Related Party Transaction [Line Items]
Related-party revenues		8,283	5,178	12,553
Transaction service fees and reimbursements [Member]
Related Party Transaction [Line Items]
Related-party revenues		12,533	25,881	64,710
Acquisition fees [Member]
Related Party Transaction [Line Items]
Related-party revenues		9,733	18,742	60,426
Disposition fees [Member]
Related Party Transaction [Line Items]
Related-party revenues		0	4,974	0
Reimbursement revenues [Member]
Related Party Transaction [Line Items]
Related-party revenues		2,800	2,165	4,284
Management fees and reimbursements [Member]
Related Party Transaction [Line Items]
Related-party revenues		68,904	59,243	50,308
Asset and property management fees and leasing fees [Member]
Related Party Transaction [Line Items]
Related-party revenues		220	452	596
Advisory and performance fee revenue [Member]
Related Party Transaction [Line Items]
Related-party revenues		51,099	44,948	40,906
Reimbursement revenues [Member]
Related Party Transaction [Line Items]
Related-party revenues		$ 17,585	$ 13,843	$ 8,806
Selling commissions allowable [Member]
Related Party Transaction [Line Items]
Selling commissions reallowed (percent)		100.00%	100.00%	100.00%
Selling commissions allowable [Member] | Cole REITs [Member]
Related Party Transaction [Line Items]
Selling commissions reallowed (percent)		100.00%	100.00%	100.00%
Dealer manager fees and/or distribution and stockholder servicing fees [Member]
Related Party Transaction [Line Items]
Related-party revenues		$ 3,200	$ 2,100	$ 9,200
Disposition fee revenue [Member] | CCIT [Member]
Related Party Transaction [Line Items]
Related-party revenues	$ 4,400
Revenue from managed real estate investment trusts, excluding fees from real estate programs [Member]
Related Party Transaction [Line Items]
Related-party revenues		$ 1,400	$ 5,300	$ 1,400