Consolidated Statement of Operations and Comprehensive Income (Loss) - USD ($) shares in Millions, $ in Millions		3 Months Ended																6 Months Ended			9 Months Ended			12 Months Ended
		Dec. 31, 2019	[1]	Sep. 30, 2019		Jun. 30, 2019		Mar. 31, 2019		Dec. 31, 2018		Sep. 30, 2018		Jun. 30, 2018		Mar. 31, 2018		Jun. 30, 2019	Jun. 30, 2018		Sep. 30, 2019	Sep. 30, 2018		Dec. 31, 2019		Dec. 31, 2018		Dec. 31, 2017
Net revenues:
Site Rental Revenues				$ 1,287		$ 1,263		$ 1,242		$ 1,231		$ 1,205		$ 1,188		$ 1,171		$ 2,505	$ 2,360		$ 3,793	$ 3,565		$ 5,093		$ 4,796		$ 3,734
Services and other				195		184		166		175		156		131		113		350	244		544	399		670		574		521
Net Revenues		$ 1,426		1,482	[1]	1,447	[1]	1,408	[1]	1,406	[1]	1,361	[1]	1,319	[1]	1,284	[1]	2,855	2,604		4,337	3,964		5,763		5,370		4,255
Costs of Operations:
Site rental	[2]			369		365		361		353		355		355		347		726	702		1,095	1,057		1,462		1,410		1,144
Services and other				146		137		124		135	[2]	118	[2]	98	[2]	85	[2]	261	183	[2]	407	301	[2]	524	[2]	434	[2]	399	[2]
Selling, general and administrative				150		155		152		145		145		138		134		307	273		457	418		614		563		426
Asset write-down charges				2		6		6		8		8		6		3		12	9		13	18		19		26		17
Acquisition and integration costs				4		2		4		9		4		8		6		6	14		10	18		13		27		61
Depreciation, amortization and accretion				388		393		394		389		385		379		374		787	753		1,175	1,138		1,572		1,527		1,241
Total operating expenses				1,059		1,058		1,041		1,039		1,015		984		949		2,099	1,934		3,157	2,950		4,204		3,987		3,288
Operating income (loss)		379		423	[1]	389	[1]	367	[1]	367	[1]	346	[1]	335	[1]	335	[1]	756	670		1,180	1,014		1,559		1,383		967
Interest expense and amortization of deferred financing costs				(173)		(169)		(168)		(164)		(160)		(158)		(160)		(337)	(318)		(510)	(478)		683		642		591
Gains (losses) on retirement of long-term obligations		0		0	[1]	(1)	[1]	(1)	[1]	0	[1]	(32)	[1]	(3)	[1]	(71)	[1]	(2)	(74)		(2)	(106)		(2)	[3]	(106)	[3]	(4)	[4]
Interest income				2		1		2		2		1		1		1		3	2		5	4		6		5		19
Other income (expense)				(5)		0		(1)		1		1		0		(1)		(1)	(1)		(6)	0		1		1		1
Income (Loss) Attributable to Parent, before Tax				247		220		199		206		156		175		104		419	279		667	434		881		641		392
Benefit (provision) for income taxes		$ (6)		(5)		(4)	[1]	(6)	[1]	(5)	[1]	(5)	[1]	(5)	[1]	(4)	[1]	(10)	(9)		(15)	(13)		(21)		(19)		(26)
Net income (loss)				242	[1]	216	[1]	193	[1]	201	[1]	151	[1]	170	[1]	100	[1]	409	270		652	421		860		622		366
Dividends, Preferred Stock				(28)		(28)		(28)		(28)		(28)		(28)		(28)		(57)	(57)		(85)	(85)		(113)		(113)		(58)
Net income (loss) attributable to CCIC common stockholders				214		188		165		173		123		142		72		352	213		567	336		747		509		308
Net income (loss)				242	[1]	216	[1]	193	[1]	201	[1]	151	[1]	170	[1]	100	[1]	409	270		652	421		860		622		366
Other comprehensive income (loss):
Foreign currency translation adjustments				0		0		0		0		0		(1)		0		0	(1)		0	(1)		0		(1)		2
Total other comprehensive income (loss)				0		0		0		0		0		(1)		0		0	(1)		0	(1)		0		(1)	[5]	2	[5]
Comprehensive income (loss) attributable to CCIC stockholders				$ 242		$ 216		$ 193		$ 201		$ 151		$ 169		$ 100		$ 409	$ 269		$ 652	$ 420		$ 860		$ 621		$ 368
Net income (loss) attributable to CCIC common stockholders, per common share:
Basic (in dollars per share)		$ 0.43		$ 0.51	[1]	$ 0.45	[1]	$ 0.40	[1]	$ 0.42	[1]	$ 0.30	[1]	$ 0.34	[1]	$ 0.18	[1]	$ 0.85	$ 0.52		$ 1.36	$ 0.81		$ 1.80		$ 1.23		$ 0.80
Diluted (in dollars per share)		$ 0.43		$ 0.51	[1]	$ 0.45	[1]	$ 0.40	[1]	$ 0.42	[1]	$ 0.30	[1]	$ 0.34	[1]	$ 0.18	[1]	$ 0.84	$ 0.52		$ 1.36	$ 0.81		$ 1.79		$ 1.23		$ 0.80
Weighted-average common shares outstanding:
Basic (in shares)				416		416		415		415		415		415		409		415	412		416	413		416		413		382
Diluted (in shares)				418		418		417		417		416		416		410		417	413		418	414		418		415		383

[1] The sum of quarterly information may not agree to year-to-date information due to rounding.

[2] Exclusive of depreciation, amortization and accretion shown separately.

[3] Inclusive of the write-off of the respective deferred financing costs.

[4] The losses represent write-off of deferred financing costs.

[5] See the consolidated statement of operations and comprehensive income (loss) for the components of "total other comprehensive income (loss)."