Goodwill and Other Intangibles - Goodwill Activity by Segment (Details)	3 Months Ended	12 Months Ended
	Dec. 31, 2016 USD ($) property	Dec. 31, 2016 USD ($) property	Dec. 31, 2015 USD ($)	Dec. 31, 2014 USD ($)	Dec. 30, 2016 property	Mar. 06, 2015 property
Goodwill [Roll Forward]
Goodwill, beginning balance		$ 1,656,374,000	$ 1,894,794,000
Goodwill allocated to dispositions and held for sale assets		(73,240,000)	(98,765,000)
Impairment	$ 0	(120,931,000)	(139,655,000)
Goodwill, ending balance	$ 1,462,203,000	$ 1,462,203,000	1,656,374,000	$ 1,894,794,000
Mortgages [Member]
Goodwill [Roll Forward]
Number of properties foreclosed upon | property	2	2			16	2
REI Segment [Member]
Goodwill [Roll Forward]
Goodwill, beginning balance		$ 1,410,631,000	1,509,396,000
Goodwill allocated to dispositions and held for sale assets		(73,240,000)	(98,765,000)
Impairment		0	0	0
Goodwill, ending balance	$ 1,337,391,000	1,337,391,000	1,410,631,000	1,509,396,000
REI Segment [Member] | Disposed of and classified as held for sale [Member]
Goodwill [Roll Forward]
Goodwill allocated to cost basis of properties	71,000,000	71,000,000
REI Segment [Member] | Properties foreclosed upon [Member]
Goodwill [Roll Forward]
Goodwill allocated to cost basis of properties	2,300,000	2,300,000
Cole Capital Segment [Member]
Goodwill [Roll Forward]
Goodwill, beginning balance		245,743,000	385,398,000
Goodwill allocated to dispositions and held for sale assets		0	0
Impairment		(120,931,000)	(139,655,000)	(223,100,000)
Goodwill, ending balance	$ 124,812,000	$ 124,812,000	$ 245,743,000	$ 385,398,000