Discontinued Operations - Effective Tax Reconciliation (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Total (benefit from) provision for income taxes - Cole Capital	$ 5,101	$ 6,882	$ 7,136
Cole Capital [Member] | Held-for-sale or Disposed of by Sale [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Loss before taxes	1,600	(5,278)	(134,774)
Less: Income from non-taxable entities	(685)	(9,523)	(9,008)
Loss attributable to taxable subsidiaries before income taxes	915	(14,801)	(143,782)
Federal provision at statutory rate (35%)	192	(5,180)	(50,324)
Impairment of goodwill	0	0	42,327
Nondeductible portion of transaction costs and loss recognized on classification as held for sale	(719)	8,283	0
Impact of change in federal tax rate	0	3,481	0
Impact of valuation allowance	(1,158)	6,165	0
State income taxes and other	(410)	1,090	(2,840)
Total (benefit from) provision for income taxes - Cole Capital	$ (2,095)	$ 13,839	$ (10,837)