Condensed Consolidated Statement of Operations and Comprehensive Income (Loss) - USD ($) shares in Millions, $ in Millions		3 Months Ended		6 Months Ended
		Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Net revenues:
Site rental		$ 1,169	$ 869	$ 2,323	$ 1,726
Network services and other		161	169	307	328
Net revenues		1,330	1,038	2,630	2,054
Operating expenses:
Site rental	[1]	355	269	702	534
Network services and other	[1]	99	104	185	203
General and administrative		138	98	273	199
Asset write-down charges		6	4	9	5
Acquisition and integration costs		8	8	14	14
Depreciation, amortization and accretion		379	296	753	584
Total operating expenses		985	779	1,936	1,539
Operating income (loss)		345	259	694	515
Nonoperating Income (Expense) [Abstract]
Interest expense and amortization of deferred financing costs		(158)	(142)	(318)	(276)
Gains (losses) on retirement of long-term obligations		(3)	0	(74)	(4)
Interest income		1	1	2	1
Other income (expense)		0	(1)	(1)	4
Income (loss) before income taxes		185	117	303	240
Benefit (provision) for income taxes		(5)	(5)	(9)	(9)
Net income (loss) attributable to CCIC stockholders		180	112	294	231
Dividends on preferred stock		(28)	0	(57)	0
Net income (loss) attributable to CCIC common stockholders		152	112	237	231
Other Comprehensive Income (Loss), Net of Tax [Abstract]
Foreign currency translation adjustments		(1)	1	(1)	1
Total other comprehensive income (loss)		(1)	1	(1)	1
Comprehensive income (loss) attributable to CCIC stockholders		$ 179	$ 113	$ 293	$ 232
Net income (loss) attributable to CCIC common stockholders, per common share:
Basic		$ 0.37	$ 0.31	$ 0.58	$ 0.64
Diluted		$ 0.36	$ 0.31	$ 0.57	$ 0.64
Weighted-average common shares outstanding (in millions):
Basic		415	364	412	363
Diluted		416	366	413	364
Common Stock, Dividends, Per Share, Declared		$ 1.05	$ 0.95	$ 2.10	$ 1.90

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