Discontinued Operations - Components of Tax Expense (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Deferred
Provision (benefit) for income taxes	$ 6,882	$ 7,136	$ 4,589
Cole Capital [Member] | Held-for-sale of Disposed of by Sale [Member]
Current
Federal	(120)	2,244	9,058
State	602	(2,762)	2,110
Total current provision	482	(518)	11,168
Deferred
Federal	12,016	(9,021)	(45,255)
State	1,341	(1,298)	(6,805)
Total deferred provision (benefit)	13,357	(10,319)	(52,060)
Provision (benefit) for income taxes	$ 13,839	$ (10,837)	$ (40,892)