Restatement of previously issued financial statements (Details) - USD ($) $ in Thousands		3 Months Ended																6 Months Ended				9 Months Ended				12 Months Ended
		Dec. 31, 2019		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		Dec. 31, 2016
Site Rental Revenues																												$ 659,490		$ 616,897
Amortization of service revenues	[1]			$ 13,436		$ 12,764		$ 12,171		$ 11,974		$ 10,846		$ 10,604		$ 10,067		$ 24,935		$ 20,671		$ 38,371		$ 31,517		$ 52,341		43,491		38,435
Property and equipment, net		$ 1,010,367		1,008,702		1,008,991		1,005,579		1,010,451		1,014,028		1,017,638		1,024,460		1,008,991		1,017,638		1,008,702		1,014,028		1,010,367		1,010,451
Deferred revenues		70,217		66,933	[2]	63,973	[2]	61,770	[2]	59,766	[3]	57,765	[2]	54,945	[2]	52,855	[2]	63,973	[2]	54,945	[2]	66,933	[2]	57,765	[2]	70,217		59,766	[3]
Liabilities, Current		144,722		148,902		137,874		147,262		78,691		86,673		75,098		84,930		137,874		75,098		148,902		86,673		144,722		78,691
Assets		4,601,457		4,609,064		4,605,388		4,611,508		3,614,120		3,651,129		3,676,760		3,707,636		4,605,388		3,676,760		4,609,064		3,651,129		4,601,457		3,614,120
Other long-term liabilities(a)	[3]	203,470		200,648	[2]	197,241	[2]	193,126	[2]	209,352		207,270	[2]	205,835	[2]	206,141	[2]	197,241	[2]	205,835	[2]	200,648	[2]	207,270	[2]	203,470		209,352
Liabilities		2,504,503		2,491,360		2,448,531		2,440,144		1,394,922		1,399,500		1,384,637		1,393,120		2,448,531		1,384,637		2,491,360		1,399,500		2,504,503		1,394,922
Members' Equity		2,096,954		2,117,704		2,156,857		2,171,364		2,219,198		2,251,629		2,292,123		2,314,516		2,156,857		2,292,123		2,117,704		2,251,629		2,096,954		2,219,198		2,371,657		$ 2,531,642
Accumulated earnings (deficit)		0		0		0		0		0		0		0		0		0		0		0		0		0		0
Liabilities and Equity		4,601,457		4,609,064		4,605,388		4,611,508		3,614,120		3,651,129		3,676,760		3,707,636		4,605,388		3,676,760		4,609,064		3,651,129		4,601,457		3,614,120
Revenues		184,864	[4]	185,181		180,953		179,493		179,306		175,954		174,660		173,061		360,446		347,721		545,627		523,675		730,491		702,981		655,332
Depreciation, amortization and accretion				51,881		51,626		51,580		51,707		51,684		52,083		52,054		103,206		104,137		155,087		155,821		207,396		207,528		207,764
Costs and Expenses				113,778		113,559		111,785		112,031		111,670		112,169		111,500		225,344		223,669		339,122		335,339		454,183		447,370		441,310
Operating income (loss)		69,803	[4]	71,403		67,394		67,708		67,275		64,284		62,491		61,561		135,102		124,052		206,505		188,336		276,308		255,611		214,022
Income (Loss) from Continuing Operations before Equity Method Investments, Income Taxes, Noncontrolling Interest				61,594		57,714		57,736		57,440		54,405		52,563		51,525		115,450		104,088		177,044		158,493		237,103		215,933		174,435
Net income (loss)		59,940	[4]	61,492		57,607		57,638		57,303		54,312		52,470		51,432		115,245		103,902		176,737		158,214		236,677		215,517		175,049
Increase (decrease) in other liabilities								5,968								6,107		9,473		6,020		15,477		10,826		18,780		15,648		779
Net Cash Provided by (Used in) Operating Activities								123,153	[5]							121,056	[5]	217,916	[5]	206,620	[5]	342,214	[5]	323,702	[5]	451,069		426,841	[5]	394,567	[5]
Payments to Acquire Productive Assets								18,678								14,766		41,358		32,300		64,204		51,995		(86,610)		(70,929)	[5]	(48,312)	[5]
Net Cash Provided by (Used in) Investing Activities	[5]							(18,678)								(14,766)		(41,358)		(32,300)		(64,204)		(51,995)		(86,610)		(70,929)		(48,312)
Increase (Decrease) Due from Affiliates								(105,472)								(108,573)		(177,586)		(183,436)		(278,231)		(278,242)		(362,759)	[6]	(367,976)	[5],[6]	(335,034)	[5],[6]
Net Cash Provided by (Used in) Financing Activities	[5]							(105,472)								(108,573)		(177,586)		(183,436)		(278,231)		(278,242)		(362,759)		(367,976)		(335,034)
Cash and Cash Equivalents, Period Increase (Decrease)								(997)								(2,283)		(1,028)		(9,116)		(221)		(6,535)		1,700		(12,064)		11,221
Cash and cash equivalents		20,407		18,486		17,679		17,710		18,707		24,236		21,655		28,488		17,679		21,655		18,486		24,236		20,407		18,707		30,771		19,550
Other Adjustment [Member]
Site Rental Revenues																												0		0
Amortization of service revenues				0		0	[1]	0	[1]	0	[1]	0	[1]	0	[1]	0	[1]	0	[1]	0	[1]	0	[1]	0	[1]			0	[1]	0	[1]
Property and equipment, net				(2,790)		(2,745)		(2,754)		(2,732)		(2,749)		(2,715)		(2,700)		(2,745)		(2,715)		(2,790)		(2,749)				(2,732)
Deferred revenues				0	[2]	0	[2]	0	[2]	0	[3]	0	[2]	0	[2]	0	[2]	0	[2]	0	[2]	0	[2]	0	[2]			0	[3]
Liabilities, Current				0		0		0		0		0		0		0		0		0		0		0				0
Assets				(2,790)		(2,745)		(2,754)		(2,732)		(2,749)		(2,715)		(2,700)		(2,745)		(2,715)		(2,790)		(2,749)				(2,732)
Other long-term liabilities(a)	[3]			0		0		0		0		0		0		0		0		0		0		0				0
Liabilities				0		0		0		0		0		0		0		0		0		0		0				0
Members' Equity				(2,790)		(2,745)		(2,754)		(2,732)		(2,749)		(2,715)		(2,700)		(2,745)		(2,715)		(2,790)		(2,749)				(2,732)		(2,688)		(1,582)
Liabilities and Equity				(2,790)		(2,745)		(2,754)				(2,749)		(2,715)		(2,700)		(2,745)		(2,715)		(2,790)		(2,749)
Revenues				0		0		0		0		0		0		0		0		0		0		0
Depreciation, amortization and accretion				(48)		(47)		(46)		(45)		(45)		(44)		(43)		(93)		(87)		(141)		(132)				(177)		(133)
Costs and Expenses				(48)		(47)		(46)		(45)		(45)		(44)		(43)		(93)		(87)		(141)		(132)				(177)		(133)
Operating income (loss)				48		47		46		45		45		44		43		93		87		141		132				177		133
Income (Loss) from Continuing Operations before Equity Method Investments, Income Taxes, Noncontrolling Interest				48		47		46		45		45		44		43		93		87		141		132				177		133
Net income (loss)				48		47		46		45		45		44		43		93		87		141		132				177		133
Increase (decrease) in other liabilities								0								0		0		0		0		0				0		0
Net Cash Provided by (Used in) Operating Activities	[5]							0								0		0		0		0		0				0		0
Payments to Acquire Productive Assets								(67)								(55)		(106)		(114)		(199)		(192)				221	[5]	1,239	[5]
Net Cash Provided by (Used in) Investing Activities								67	[5]							55	[5]	106	[5]	114	[5]	199	[5]	192	[5]			221		1,239
Increase (Decrease) Due from Affiliates								(67)								(55)		(106)		(114)		(199)		(192)				(221)	[5]	(1,239)	[5]
Net Cash Provided by (Used in) Financing Activities								(67)	[5]							(55)	[5]	(106)	[5]	(114)	[5]	(199)	[5]	(192)	[5]			(221)		(1,239)
Cash and Cash Equivalents, Period Increase (Decrease)								0								0		0		0		0		0				0		0
Cash and cash equivalents				0		0		0		0		0		0		0		0		0		0		0				0		0		0
Restatement Adjustment [Member]
Site Rental Revenues																												0		0
Amortization of service revenues				13,436		12,764	[1]	12,171	[1]	11,974	[1]	10,846	[1]	10,604	[1]	10,067	[1]	24,935	[1]	20,671	[1]	38,371	[1]	31,517	[1]			43,491	[1]	38,435	[1]
Property and equipment, net				(4,140)		(4,288)		(4,436)		(4,584)		(4,740)		(4,897)		(5,054)		(4,288)		(4,897)		(4,140)		(4,740)				(4,584)
Asset Retirement Obligations, Noncurrent										(22,600)																		(22,600)
Deferred revenues				53,543	[2]	51,626	[2]	49,334	[2]	47,233	[3]	46,056	[2]	42,902	[2]	40,926	[2]	51,626	[2]	42,902	[2]	53,543	[2]	46,056	[2]			47,233	[3]
Liabilities, Current				53,543		51,626		49,334		47,233		46,056		42,902		40,926		51,626		42,902		53,543		46,056				47,233
Assets				(4,140)		(4,288)		(4,436)		(4,584)		(4,740)		(4,897)		(5,054)		(4,288)		(4,897)		(4,140)		(4,740)				(4,584)
Other long-term liabilities(a)	[3]			165,030		162,240		158,784		159,244		157,334		156,147		156,685		162,240		156,147		165,030		157,334				159,244
Liabilities				218,573		213,866		208,118		206,477		203,390		199,049		197,611		213,866		199,049		218,573		203,390				206,477
Members' Equity				(222,713)		(218,154)		(212,554)		(211,061)		(208,130)		(203,946)		(202,665)		(218,154)		(203,946)		(222,713)		(208,130)				(211,061)		(202,126)		(206,021)
Liabilities and Equity				(4,140)		(4,288)		(4,436)		(4,584)		(4,740)		(4,897)		(5,054)		(4,288)		(4,897)		(4,140)		(4,740)				(4,584)
Revenues				13,436		12,764		12,171		11,974		10,846		10,604		10,067		24,935		20,671		38,371		31,517				43,491		38,435
Depreciation, amortization and accretion				(736)		(736)		(736)		(555)		(604)		(604)		(604)		(1,472)		(1,208)		(2,208)		(1,812)				(2,367)		(2,710)
Costs and Expenses				(736)		(736)		(736)		(555)		(604)		(604)		(604)		(1,472)		(1,208)		(2,208)		(1,812)				(2,367)		(2,710)
Operating income (loss)				14,172		13,500		12,907		12,529		11,450		11,208		10,671		26,407		21,879		40,579		33,329				45,858		41,145
Income (Loss) from Continuing Operations before Equity Method Investments, Income Taxes, Noncontrolling Interest				14,172		13,500		12,907		12,529		11,450		11,208		10,671		26,407		21,879		40,579		33,329				45,858		41,145
Net income (loss)				14,172		13,500		12,907		12,529		11,450		11,208		10,671		26,407		21,879		40,579		33,329				45,858		41,145
Increase (decrease) in other liabilities								2,230								1,143		8,565		3,028		13,860		7,817				11,302		(1,185)
Net Cash Provided by (Used in) Operating Activities	[5]							14,401								11,210		33,500		23,699		52,231		39,334				54,793		37,250
Payments to Acquire Productive Assets								0								0		0		0		0		0				0	[5]	0	[5]
Net Cash Provided by (Used in) Investing Activities								0	[5]							0	[5]	0	[5]	0	[5]	0	[5]	0	[5]			0		0
Increase (Decrease) Due from Affiliates								(14,401)								(11,210)		(33,500)		(23,699)		(52,231)		(39,334)				(54,793)	[5]	(37,250)	[5]
Net Cash Provided by (Used in) Financing Activities								(14,401)	[5]							(11,210)	[5]	(33,500)	[5]	(23,699)	[5]	(52,231)	[5]	(39,334)	[5]			(54,793)		(37,250)
Cash and Cash Equivalents, Period Increase (Decrease)								0								0		0		0		0		0				0		0
Cash and cash equivalents				0		0		0		0		0		0		0		0		0		0		0				0		0		0
restatement adjustment for ARO [Member]
Members' Equity										18,000																		18,000
Previously Reported [Member]
Site Rental Revenues																												659,490		616,897
Amortization of service revenues				0		0	[1]	0	[1]	0	[1]	0	[1]	0	[1]	0	[1]	0	[1]	0	[1]	0	[1]	0	[1]			0	[1]	0	[1]
Property and equipment, net				1,015,632		1,016,024		1,012,769		1,017,767		1,021,517		1,025,250		1,032,214		1,016,024		1,025,250		1,015,632		1,021,517				1,017,767
Deferred revenues				13,390	[2]	12,347	[2]	12,436	[2]	12,533	[3]	11,709	[2]	12,043	[2]	11,929	[2]	12,347	[2]	12,043	[2]	13,390	[2]	11,709	[2]			12,533	[3]
Liabilities, Current				95,359		86,248		97,928		31,458		40,617		32,196		44,004		86,248		32,196		95,359		40,617				31,458
Assets				4,615,994		4,612,421		4,618,698		3,621,436		3,658,618		3,684,372		3,715,390		4,612,421		3,684,372		4,615,994		3,658,618				3,621,436
Other long-term liabilities(a)	[3]			35,618		35,001		34,342		50,108		49,936		49,688		49,456		35,001		49,688		35,618		49,936				50,108
Liabilities				2,272,787		2,234,665		2,232,026		1,188,445		1,196,110		1,185,588		1,195,509		2,234,665		1,185,588		2,272,787		1,196,110				1,188,445
Members' Equity				2,343,207		2,377,756		2,386,672		2,432,991		2,462,508		2,498,784		2,519,881		2,377,756		2,498,784		2,343,207		2,462,508				2,432,991		2,576,471		2,739,245
Liabilities and Equity				4,615,994		4,612,421		4,618,698		3,621,436		3,658,618		3,684,372		3,715,390		4,612,421		3,684,372		4,615,994		3,658,618				3,621,436
Revenues				171,745		168,189		167,322		167,332		165,108		164,056		162,994		335,511		327,050		507,256		492,158				659,490		616,897
Depreciation, amortization and accretion				52,665		52,409		52,362		52,307		52,333		52,731		52,701		104,771		105,432		157,436		157,765				210,072		210,607
Costs and Expenses				114,562		114,342		112,567		112,631		112,319		112,817		112,147		226,909		224,964		341,471		337,283				449,914		444,153
Operating income (loss)				57,183		53,847		54,755		54,701		52,789		51,239		50,847		108,602		102,086		165,785		154,875				209,576		172,744
Income (Loss) from Continuing Operations before Equity Method Investments, Income Taxes, Noncontrolling Interest				47,374		44,167		44,783		44,866		42,910		41,311		40,811		88,950		82,122		136,324		125,032				169,898		133,157
Net income (loss)				47,272		44,060		44,685		44,729		42,817		41,218		40,718		88,745		81,936		136,017		124,753				169,482		133,771
Increase (decrease) in other liabilities								3,738								4,964		908		2,992		1,617		3,009				4,346		1,964
Net Cash Provided by (Used in) Operating Activities	[5]							108,752								109,846		184,416		182,921		289,983		284,368				372,048		357,317
Payments to Acquire Productive Assets								18,745								14,821		41,464		32,414		64,403		52,187				(71,150)	[5]	(49,551)	[5]
Net Cash Provided by (Used in) Investing Activities								(18,745)	[5]							(14,821)	[5]	(41,464)	[5]	(32,414)	[5]	(64,403)	[5]	(52,187)	[5]			(71,150)		(49,551)
Increase (Decrease) Due from Affiliates								(91,004)								(97,308)		(143,980)		(159,623)		(225,801)		(238,716)				(312,962)	[5]	(296,545)	[5]
Net Cash Provided by (Used in) Financing Activities								(91,004)	[5]							(97,308)	[5]	(143,980)	[5]	(159,623)	[5]	(225,801)	[5]	(238,716)	[5]			(312,962)		(296,545)
Cash and Cash Equivalents, Period Increase (Decrease)								(997)								(2,283)		(1,028)		(9,116)		(221)		(6,535)				(12,064)		11,221
Cash and cash equivalents				$ 18,486		$ 17,679		$ 17,710		18,707		$ 24,236		$ 21,655		$ 28,488		$ 17,679		$ 21,655		$ 18,486		$ 24,236				18,707		30,771		19,550
Other [Member]
Liabilities and Equity										(2,732)																		(2,732)
Revenues																												0		0
Members' Capital [Member]
Members' Equity		$ 2,096,954								$ 2,219,198																2,096,954		2,219,198		2,371,657		$ 2,531,642
Net income (loss)																										0		0		0
Increase (Decrease) Due from Affiliates	[6]																									$ (126,082)		$ (152,459)		$ (159,985)

[1] Represents the amortization of deferred revenues recorded in connection with the CCIC transactions described in note 2 that result in permanent improvements to the Company's towers. The Company receives no cash from, and is not party to, such transactions

[2] Reflects the recording of deferred revenues in connection with the CCIC transactions described in note 2 that result in permanent improvements to the Company's towers . The Company receives no cash from, and is not party to, such transactions.   September 30, 2018   June 30, 2018   March 31, 2018   (As Restated) ASSETS           Current assets:           Cash and cash equivalents $ 24,236
  $ 21,655
  $ 28,488
Receivables, net of allowance 2,740
  2,350
  2,744
Prepaid expenses^(a) 28,615
  27,444
  19,305
Deferred site rental receivables and other current assets 25,739
  39,928
  29,478
Total current assets 81,330
  91,377
  80,015
Deferred site rental receivables 341,633
  325,070
  331,907
Property and equipment, net 1,014,028
  1,017,638
  1,024,460
Goodwill 1,338,730
  1,338,730
  1,338,730
Other intangible assets, net^(a) 836,156
  864,946
  893,735
Long-term prepaid rent and other assets, net^(a) 39,252
  38,999
  38,789
Total assets $ 3,651,129
  $ 3,676,760
  $ 3,707,636
LIABILITIES AND EQUITY           Current liabilities:           Accounts payable $ 2,325
  $ 2,443
  $ 1,738
Accrued interest 17,748
  8,126
  17,748
Deferred revenues^(b) 57,765
  54,945
  52,855
Other accrued liabilities^(a) 8,835
  9,584
  12,589
Total current liabilities 86,673
  75,098
  84,930
Debt 993,701
  993,355
  993,009
Deferred ground lease payable^(a) 111,856
  110,349
  109,040
Other long-term liabilities^(a)(b) 207,270
  205,835
  206,141
Total liabilities 1,399,500
  1,384,637
  1,393,120
Commitments and contingencies (see note 10)           Member's equity:           Member's equity 2,251,629
  2,292,123
  2,314,516
Accumulated earnings (deficit) —
  —
  —
Total member's equity 2,251,629
  2,292,123
  2,314,516
Total liabilities and equity $ 3,651,129
  $ 3,676,760
  $ 3,707,636
     (a)

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

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

[5] The Company receives no cash from, and is not party to, the CCIC transactions described in note 2. Such transactions, however, are reflected on the cash flow statement for GAAP purposes as if an amount equal to the lease component for such transactions had been received by the Company, and as such, the amounts have been recorded as fixed assets (in the form of permanent improvements) and deferred revenues.

[6] The Company receives no cash from, and is not party to, the CCIC transactions described in note 2.