Segment Data	9 Months Ended
	Sep. 30, 2021
Segment Data [Abstract]
Segment Data	14.SEGMENT DATAThe Company operates principally in two business segments: site leasing and site development. The Company’s site leasing business includes two reportable segments, domestic site leasing and international site leasing. The Company’s business segments are strategic business units that offer different services. They are managed separately based on the fundamental differences in their operations. The site leasing segment includes results of the managed and sublease businesses. The site development segment includes the results of both consulting and construction related activities. The Company’s Chief Operating Decision Maker utilizes segment operating profit and operating income as his two measures of segment profit in assessing performance and allocating resources at the reportable segment level. The Company has applied the aggregation criteria to operations within the international site leasing segment on a basis that is consistent with management’s review of information and performance evaluations of the individual markets in this region.Revenues, cost of revenues (exclusive of depreciation, accretion and amortization), capital expenditures (including assets acquired through the issuance of shares of the Company’s Class A common stock) and identifiable assets pertaining to the segments in which the Company continues to operate are presented below. Domestic Site Int'l Site Site Leasing Leasing Development Other Total For the three months ended September 30, 2021 (in thousands)Revenues $ 426,758  $ 108,734  $ 53,813  $ — $ 589,305 Cost of revenues (1) 65,260  33,406  41,357  — 140,023 Operating profit 361,498  75,328  12,456  — 449,282 Selling, general, and administrative expenses 27,983  9,272  4,791  8,954  51,000 Acquisition and new business initiatives related adjustments and expenses 2,911  2,819  — — 5,730 Asset impairment and decommission costs 6,113  3,747  — — 9,860 Depreciation, amortization and accretion 123,705  45,035  565  1,611  170,916 Operating income (loss) 200,786  14,455  7,100  (10,565) 211,776 Other expense (principally interest expense and other expense) (174,812) (174,812)Income before income taxes 36,964 Cash capital expenditures (2) 39,062  51,897  221  1,755  92,935  For the three months ended September 30, 2020 Revenues $ 390,961  $ 95,804  $ 36,175  $ — $ 522,940 Cost of revenues (1) 64,228  28,494  28,797  — 121,519 Operating profit 326,733  67,310  7,378  — 401,421 Selling, general, and administrative expenses 25,466  8,747  4,518  9,421  48,152 Acquisition and new business initiatives related adjustments and expenses 2,458  1,666  — — 4,124 Asset impairment and decommission costs 6,129  2,377  — — 8,506 Depreciation, amortization and accretion 135,350  42,851  578  1,523  180,302 Operating income (loss) 157,330  11,669  2,282  (10,944) 160,337 Other expense (principally interest expense and other expense) (147,102) (147,102)Income before income taxes 13,235 Cash capital expenditures (2) 89,982  17,971  127  1,176  109,256  ‎ Domestic Site Int'l Site Site Leasing Leasing Development Other Total For the nine months ended September 30, 2021 (in thousands)Revenues $ 1,249,291  $ 315,523  $ 148,882  $ — $ 1,713,696 Cost of revenues (1) 194,455  95,055  116,172  — 405,682 Operating profit 1,054,836  220,468  32,710  — 1,308,014 Selling, general, and administrative expenses 85,240  26,553  14,574  30,179  156,546 Acquisition and new business initiatives related adjustments and expenses 10,839  6,686  — — 17,525 Asset impairment and decommission costs 12,674  5,740  — 146  18,560 Depreciation, amortization and accretion 390,730  132,900  1,727  4,909  530,266 Operating income (loss) 555,353  48,589  16,409  (35,234) 585,117 Other expense (principally interest expense and other expense) (380,903) (380,903)Income before income taxes 204,214 Cash capital expenditures (2) 1,186,791  87,572  1,812  3,751  1,279,926  For the nine months ended September 30, 2020 Revenues $ 1,165,322  $ 296,201  $ 85,708  $ — $ 1,547,231 Cost of revenues (1) 192,226  87,894  68,417  — 348,537 Operating profit 973,096  208,307  17,291  — 1,198,694 Selling, general, and administrative expenses 78,021  25,713  13,468  29,654  146,856 Acquisition and new business initiatives related adjustments and expenses 8,059  4,498  — — 12,557 Asset impairment and decommission costs 22,297  6,806  — — 29,103 Depreciation, amortization and accretion 403,725  131,474  1,791  4,597  541,587 Operating income (loss) 460,994  39,816  2,032  (34,251) 468,591 Other expense (principally interest expense and other expense) (626,873) (626,873)Loss before income taxes (158,282)Cash capital expenditures (2) 229,795  61,605  1,191  3,572  296,163  Domestic Site Int'l Site Site Leasing Leasing Development Other (3) Total Assets (in thousands)As of September 30, 2021 $ 6,638,499  $ 2,768,258  $ 79,432  $ 181,893  $ 9,668,082 As of December 31, 2020 $ 5,893,636  $ 2,955,563  $ 61,729  $ 247,090  $ 9,158,018  (1)Excludes depreciation, amortization, and accretion.(2)Includes cash paid for capital expenditures, acquisitions, and right-of-use assets.(3)Assets in Other consist primarily of general corporate assets and short-term investments.For the nine months ended September 30, 2021 and 2020, site leasing revenue in Brazil was $174.5 million and $167.8 million, respectively. Other than Brazil, no foreign country represented a material amount of the Company’s total revenues in any of the periods presented. Total long-lived assets in Brazil were $0.9 billion and $1.0 billion as of September 30, 2021 and December 31, 2020, respectively.