Segment Reporting - Schedule of Financial Results by Segment (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016	Dec. 31, 2016
Revenues:
Rental income	$ 286,291	$ 311,352	$ 580,030	$ 625,323
Direct financing lease income	403	535	836	1,104
Operating expense reimbursements	21,551	26,646	48,277	49,893
Total revenues	336,930	371,019	684,959	740,039
Operating expenses:
Cole Capital reallowed fees and commissions	2,874	6,975	5,534	15,043
Acquisition-related	756	41	1,373	283
Litigation and other non-routine costs, net of insurance recoveries	14,411	2,917	27,286	(2,258)
Property operating	31,627	38,199	65,643	73,012
General and administrative	29,411	33,094	58,559	62,494
Depreciation and amortization	184,288	197,345	367,440	401,653
Impairment of real estate	17,769	8,825	24,494	169,342
Total operating expenses	281,136	287,396	550,329	719,569
Operating income	55,794	83,623	134,630	20,470
Other (expense) income:
Interest expense	(73,621)	(82,468)	(147,364)	(162,894)
Gain on extinguishment and forgiveness of debt, net	9,005	252	8,935	252
Other income, net	1,835	1,216	2,633	2,278
Equity in income and gain on disposition of unconsolidated entities	513	70	431	10,474
Gain (loss) on derivative instruments, net	592	(177)	1,416	(1,263)
Total other expenses, net	(61,676)	(81,107)	(133,949)	(151,153)
(Loss) income before taxes and real estate dispositions	(5,882)	2,516	681	(130,683)
Gain on disposition of real estate and held for sale assets, net	42,639	437	55,120	17,612
Income (loss) before taxes	36,757	2,953	55,801	(113,071)
(Provision for) benefit from income taxes	(2,571)	280	(6,825)	224
Net income (loss)	34,186	3,233	48,976	(112,847)
Total Assets	15,048,040		15,048,040		$ 15,587,574
Total Company:
Total revenues	336,930	371,019	684,959	740,039
Total operating expenses	(281,136)	(287,396)	(550,329)	(719,569)
Total other expense, net	(61,676)	(81,107)	(133,949)	(151,153)
Net income (loss)	34,186	3,233	48,976	(112,847)
REI segment [Member]
Revenues:
Rental income	286,291	311,352	580,030	625,323
Direct financing lease income	403	535	836	1,104
Operating expense reimbursements	21,551	26,646	48,277	49,893
Total revenues	308,245	338,533	629,143	676,320
Operating expenses:
Acquisition-related	720	27	1,337	244
Litigation and other non-routine costs, net of insurance recoveries	14,411	2,917	27,286	(2,258)
Property operating	31,627	38,199	65,643	73,012
General and administrative	14,294	13,701	26,854	25,929
Depreciation and amortization	179,433	190,236	357,730	386,227
Impairment of real estate	17,769	8,825	24,494	169,342
Total operating expenses	258,254	253,905	503,344	652,496
Operating income	49,991	84,628	125,799	23,824
Other (expense) income:
Interest expense	(73,621)	(82,468)	(147,364)	(162,894)
Gain on extinguishment and forgiveness of debt, net	9,005	252	8,935	252
Other income, net	1,759	1,216	2,429	1,784
Equity in income and gain on disposition of unconsolidated entities	513	70	431	10,474
Gain (loss) on derivative instruments, net	592	(177)	1,416	(1,263)
Total other expenses, net	(61,752)	(81,107)	(134,153)	(151,647)
(Loss) income before taxes and real estate dispositions	(11,761)	3,521	(8,354)	(127,823)
Gain on disposition of real estate and held for sale assets, net	42,639	437	55,120	17,612
Income (loss) before taxes	30,878	3,958	46,766	(110,211)
(Provision for) benefit from income taxes	(1,146)	(1,791)	(4,254)	(3,156)
Net income (loss)	29,732	2,167	42,512	(113,367)
Total Assets	14,790,320		14,790,320		15,337,623
Total Company:
Total revenues	308,245	338,533	629,143	676,320
Total operating expenses	(258,254)	(253,905)	(503,344)	(652,496)
Total other expense, net	(61,752)	(81,107)	(134,153)	(151,647)
Net income (loss)	29,732	2,167	42,512	(113,367)
Cole Capital segment [Member]
Revenues:
Offering-related fees and reimbursements	4,523	10,914	8,839	23,305
Transaction service fees and reimbursements	5,062	4,476	9,159	6,860
Management fees and reimbursements	19,100	17,096	37,818	33,554
Total revenues	28,685	32,486	55,816	63,719
Operating expenses:
Cole Capital reallowed fees and commissions	2,874	6,975	5,534	15,043
Acquisition-related	36	14	36	39
General and administrative	15,117	19,393	31,705	36,565
Depreciation and amortization	4,855	7,109	9,710	15,426
Total operating expenses	22,882	33,491	46,985	67,073
Operating income	5,803	(1,005)	8,831	(3,354)
Other (expense) income:
Total other expenses, net	76	0	204	494
Income (loss) before taxes	5,879	(1,005)	9,035	(2,860)
(Provision for) benefit from income taxes	(1,425)	2,071	(2,571)	3,380
Net income (loss)	4,454	1,066	6,464	520
Total Assets	257,720		257,720		$ 249,951
Total Company:
Total revenues	28,685	32,486	55,816	63,719
Total operating expenses	(22,882)	(33,491)	(46,985)	(67,073)
Total other expense, net	76	0	204	494
Net income (loss)	$ 4,454	$ 1,066	$ 6,464	$ 520