Quarterly Financial Information Restatement of 2018 Quarterly Balance Sheet (Details) - USD ($) $ in Millions		Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018		Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Cash and cash equivalents		$ 196	$ 182	$ 288	$ 245	$ 277		$ 323	$ 206	$ 220	$ 314
Restricted cash		137	138	136	158	131		125	125	120	121
Receivables, net of allowance		596	667	591	545	501		471	455	402
Prepaid expenses	[1]	107	99	111	85	172		182	197	175
Other current assets		168	167	168	160	148		148	181	157
Assets, Current		1,204	1,253	1,294	1,193	1,229		1,249	1,164	1,074
Deferred site rental receivables		1,424	1,413	1,391	1,373	1,366		1,357	1,303	1,304
Property and equipment, net		14,666	14,393	14,128	13,860	13,653		13,410	13,195	13,028
Operating Lease, Right-of-Use Asset	[1]	6,133	6,112	6,053	5,969	0
Goodwill		10,078	10,078		10,078	10,078		10,074	10,075	10,075	10,021
Site rental contracts and tenant relationships, net		4,764				5,209
Other intangible assets, net	[1]	72	4,968	5,074	5,178	307		5,620	5,729	5,854
Long-term prepaid rent and other assets, net	[1]	116	104		104	920		911	885	892
Assets		38,457	38,321	38,124	37,755	32,762		32,621	32,351	32,227
LIABILITIES AND EQUITY
Accounts payable		334	368	337	311	313		302	272	248
Accrued interest		169	110	166	107	148		101	154	104
Deferred revenues		657	638	607	598	587		568	554	539
Other accrued liabilities	[1]	361	335	305	262	351		306	272	240
Current maturities of debt and other obligations		100	100	98	96	107		111	112	130
Current portion of operating lease liabilities	[1]	299	296	289	287	0
Liabilities, Current		1,920	1,847	1,802	1,661	1,506		1,388	1,364	1,261
Debt and other long-term obligations		18,021	17,750	17,471	17,120	16,575		16,313	15,844	15,616
Operating lease liabilities	[1]	5,511	5,480	5,427	5,338	0
Other long-term liabilities	[1]	2,516	2,458	2,411	2,369	3,110		3,074	3,014	2,946
Liabilities		27,968	27,535	27,111	26,488	21,191		20,775	20,222	19,823
CCIC stockholders' equity:
Common stock, $0.01 par value		4	4	4	4	4		4	4	4
6.875% Mandatory Convertible Preferred Stock, Series A, $0.01 par value		0	0	0	0	0		0	0	0
Additional paid-in capital		17,855	17,829	17,801	17,769	17,767		17,743	17,711	17,690
Accumulated other comprehensive income (loss)		(5)	(5)	(5)	(5)	(5)		(5)	(5)	(4)
Dividends/distributions in excess of earnings		(7,365)	(7,042)	(6,787)	(6,501)	(6,195)		(5,896)	(5,581)	(5,286)	(4,919)	$ (3,714)
Total equity		10,489	10,786	11,013	11,267	11,571		11,846	12,129	12,404	11,925	7,222
Liabilities and Equity		$ 38,457	38,321	38,124	37,755	32,762		32,621	32,351	32,227
Previously Reported [Member]
Property and equipment, net			14,416	14,151	13,883	13,676		13,433	13,218	13,051
Assets			38,344	38,147	37,778	32,785		32,644	32,374	32,250
LIABILITIES AND EQUITY
Deferred revenues			525	503	502	498		484	476	465
Liabilities, Current			1,734	1,698	1,565	1,417		1,304	1,286	1,187
Other long-term liabilities	[1]		2,055	2,028	2,009	2,759		2,732	2,678	2,615
Liabilities			27,019	26,624	26,032	20,751		20,349	19,808	19,418
CCIC stockholders' equity:
Dividends/distributions in excess of earnings			(6,503)	(6,277)	(6,022)	(5,732)		(5,447)	(5,144)	(4,858)	(4,505)	(3,379)
Total equity			11,325	11,523	11,746	12,034		12,295	12,566	12,832	12,339	7,557
Liabilities and Equity			38,344	38,147	37,778	32,785		32,644	32,374	32,250
Restatement Adjustment [Member]
Property and equipment, net			0	0	0	0		0	0	0
Assets			0	0	0	0		0	0	0
LIABILITIES AND EQUITY
Deferred revenues			113	104	96	89		84	78	74
Liabilities, Current			113	104	96	89		84	78	74
Other long-term liabilities	[1]		403	383	360	351		342	336	331
Liabilities			516	487	456	440		426	414	405
CCIC stockholders' equity:
Dividends/distributions in excess of earnings			(516)	(487)	(456)	(440)		(426)	(414)	(405)	(391)	(332)
Total equity			(516)	(487)	(456)	(440)		(426)	(414)	(405)	(391)	(332)
Liabilities and Equity			0	0	0	0		0	0	0
Other Adjustments [Domain]
Property and equipment, net			(23)	(23)	(23)	(23)		(23)	(23)	(23)
Assets			(23)	(23)	(23)	(23)		(23)	(23)	(23)
LIABILITIES AND EQUITY
Deferred revenues			0	0	0	0		0	0	0
Liabilities, Current			0	0	0	0		0	0	0
Other long-term liabilities			0	0	0	0	[1]	0	0	0
Liabilities			0	0	0	0		0	0	0
CCIC stockholders' equity:
Dividends/distributions in excess of earnings			(23)	(23)	(23)	(23)		(23)	(23)	(23)	(23)	(3)
Total equity			(23)	(23)	(23)	(23)		(23)	(23)	(23)	$ (23)	$ (3)
Liabilities and Equity			$ (23)	$ (23)	$ (23)	$ (23)		$ (23)	$ (23)	$ (23)

[1] See "Recently Adopted Accounting Pronouncements" in note 3 to the consolidated financial statements for a discussion of the recently adopted new lease standard.