Segment Reporting (Details) - USD ($) $ in Thousands		3 Months Ended		9 Months Ended
		Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014	Dec. 31, 2014
Segment Reporting Information [Line Items]
Rental income		$ 333,766	$ 365,712	$ 1,017,708	$ 924,646
Direct financing lease income		659	625	2,097	2,812
Operating expense reimbursements		22,983	30,984	71,269	81,716
Total revenues		384,954	457,118	1,172,643	1,160,450
Acquisition related	[1]	1,764	13,998	5,509	34,616
Merger and other non-routine transactions	[2]	8,957	7,632	42,244	175,352
Property operating		31,950	40,977	95,547	110,018
Management fees to affiliates		0	0	0	13,888
General and administrative	[3]	32,842	30,213	99,906	122,806
Depreciation and amortization		208,542	265,150	645,196	689,731
Impairment of real estate				85,341	3,855
Total operating expenses		287,951	375,667	983,380	1,207,168
Operating income (loss)		97,003	81,451	189,263	(46,718)
Extinguishment and forgiveness of debt, net		0	(5,396)	5,302	(21,264)
Other income, net		3,401	8,687	12,791	17,104
Loss on derivative instruments, net		(1,420)	(17,484)	(2,137)	(10,398)
Gain on sale of investments				65	6,357
Total other expenses, net		(80,820)	(109,479)	(253,116)	(334,692)
Income (loss) before income and franchise taxes and loss on disposition of real estate and held for sale assets		16,183	(28,028)	(63,853)	(381,410)
Loss on disposition of real estate and held for sale assets, net		(6,542)	(256,894)	(62,584)	(275,768)
Income (loss) before income and franchise taxes		9,641	(284,922)	(126,437)	(657,178)
Benefit from (provision for) income taxes		(1,500)	(3,125)	(4,824)	6,693
Net income (loss)		8,141	(288,047)	(131,261)	(650,485)
Cole Capital reallowed fees and commissions		3,896	15,398	9,637	56,902
Assets		18,704,888		18,704,888		$ 20,515,139
REI Segment [Member]
Segment Reporting Information [Line Items]
Rental income		333,766	365,712	1,017,708	924,646
Direct financing lease income		659	625	2,097	2,812
Operating expense reimbursements		22,983	30,984	71,269	81,716
Total revenues		357,408	397,321	1,091,074	1,009,174
Acquisition related		1,690	13,998	4,976	34,616
Merger and other non-routine transactions		8,957	7,613	42,244	173,406
Property operating		31,950	40,977	95,547	110,018
Management fees to affiliates		0	0	0	13,888
General and administrative		15,848	12,948	48,045	62,675
Depreciation and amortization		200,158	240,073	620,068	625,521
Impairment of real estate		0	2,299	85,341	3,855
Total operating expenses		258,603	317,908	896,221	1,023,979
Operating income (loss)		98,805	79,413	194,853	(14,805)
Interest expense, net		(89,530)	(101,643)	(275,801)	(326,491)
Extinguishment and forgiveness of debt, net		0	(5,396)	5,302	(21,264)
Other income, net		2,936	8,508	10,715	16,799
Gain on disposition of interest in joint venture		6,729	0	6,729	0
Loss on derivative instruments, net		(1,420)	(17,484)	(2,137)	(10,398)
Gain on sale of investments		0	6,357	0	6,357
Total other expenses, net		(81,285)	(109,658)	(255,192)	(334,997)
Income (loss) before income and franchise taxes and loss on disposition of real estate and held for sale assets		17,520	(30,245)	(60,339)	(349,802)
Loss on disposition of real estate and held for sale assets, net		(6,542)	(256,894)	(62,584)	(275,768)
Income (loss) before income and franchise taxes		10,978	(287,139)	(122,923)	(625,570)
Benefit from (provision for) income taxes		(2,238)	(1,994)	(7,211)	(5,905)
Net income (loss)		8,740	(289,133)	(130,134)	(631,475)
Assets		18,008,818		18,008,818		19,771,138
Cole Capital segment [Member]
Segment Reporting Information [Line Items]
Total revenues		27,546	59,797	81,569	151,276
Acquisition related		74	0	533	0
Merger and other non-routine transactions		0	19	0	1,946
General and administrative		16,994	17,265	51,861	60,131
Depreciation and amortization		8,384	25,077	25,128	64,210
Total operating expenses		29,348	57,759	87,159	183,189
Operating income (loss)		(1,802)	2,038	(5,590)	(31,913)
Total other expenses, net		465	179	2,076	305
Income (loss) before income and franchise taxes		(1,337)	2,217	(3,514)	(31,608)
Benefit from (provision for) income taxes		738	(1,131)	2,387	12,598
Net income (loss)		(599)	1,086	(1,127)	(19,010)
Offering-related fees and reimbursements		5,850	21,535	14,483	73,957
Transaction service fees and reimbursements		7,400	24,423	24,696	44,406
Management fees and reimbursements		14,296	13,839	42,390	32,913
Cole Capital reallowed fees and commissions		3,896	$ 15,398	9,637	$ 56,902
Assets		$ 696,070		$ 696,070		$ 744,001

[1] Includes $1.7 million of expenses incurred during the nine months ended September 30, 2014, paid to affiliates. No such expenses were incurred during the three months ended September 30, 2014 or the three and nine months ended September 30, 2015.

[2] Includes $137.8 million of expenses incurred during the nine months ended September 30, 2014, paid to affiliates. No such expenses were incurred during the three months ended September 30, 2014 or the three and nine months ended September 30, 2015.

[3] Includes $60,000 and $16.1 million of expenses incurred during the three and nine months ended September 30, 2014, respectively, paid to affiliates. No such expenses were incurred during the three and nine months ended September 30, 2015.