Segment Data (Schedule of Segment Reporting Information) (Details) - USD ($) $ in Thousands		3 Months Ended		6 Months Ended
		Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019	Dec. 31, 2019
Segment Reporting Information [Line Items]
Revenues		$ 507,226	$ 500,147	$ 1,024,292	$ 993,440
Cost of revenues		111,502	124,448	227,017	248,264
Operating profit		395,724	375,699	797,275	745,176
Selling, general, and administrative expenses	[1]	49,088	55,524	98,704	106,483
Acquisition and new business initiatives related adjustments and expenses		4,634	2,539	8,433	4,976
Asset impairment and decommission costs		6,242	9,620	20,597	15,391
Depreciation, amortization and accretion		178,706	171,564	361,285	342,602
Operating income		157,054	136,452	308,256	275,724
Other expense (principally interest expense and other income (expense))		(134,101)	(88,871)	(479,774)	(191,947)
Income (loss) before income taxes		22,953	47,581	(171,518)	83,777
Cash capital expenditures		57,192	133,118	186,907	225,645
Assets		9,390,539		9,390,539		$ 9,759,941
Domestic Site Leasing [Member]
Segment Reporting Information [Line Items]
Revenues		388,018	369,180	774,361	732,017
Cost of revenues		64,093	65,576	127,997	130,690
Operating profit		323,925	303,604	646,364	601,327
Selling, general, and administrative expenses		25,233	27,193	52,555	56,086
Acquisition and new business initiatives related adjustments and expenses		3,004	1,272	5,601	1,980
Asset impairment and decommission costs		5,342	8,815	16,168	12,449
Depreciation, amortization and accretion		134,569	131,413	268,375	261,657
Operating income		155,777	134,911	303,665	269,155
Cash capital expenditures		38,507	113,200	139,813	174,710
Assets		5,996,130		5,996,130		6,157,511
International Site Leasing [Member]
Segment Reporting Information [Line Items]
Revenues		94,385	89,823	200,397	179,169
Cost of revenues		27,505	27,884	59,400	55,485
Operating profit		66,880	61,939	140,997	123,684
Selling, general, and administrative expenses		9,035	8,310	16,966	13,998
Acquisition and new business initiatives related adjustments and expenses		1,630	1,267	2,832	2,996
Asset impairment and decommission costs		900	805	4,429	2,942
Depreciation, amortization and accretion		42,011	38,194	88,623	76,989
Operating income		13,304	13,363	28,147	26,759
Cash capital expenditures		17,201	18,411	43,634	47,928
Assets		2,893,042		2,893,042		3,381,448
Site Development [Member]
Segment Reporting Information [Line Items]
Revenues		24,823	41,144	49,534	82,254
Cost of revenues		19,904	30,988	39,620	62,089
Operating profit		4,919	10,156	9,914	20,165
Selling, general, and administrative expenses		4,494	6,885	8,950	12,591
Depreciation, amortization and accretion		597	678	1,213	1,240
Operating income		(172)	2,593	(249)	6,334
Cash capital expenditures		282	883	1,064	1,808
Assets		50,702		50,702		81,772
Not Identified by Segment [Member]
Segment Reporting Information [Line Items]
Selling, general, and administrative expenses		10,326	13,136	20,233	23,808
Depreciation, amortization and accretion		1,529	1,279	3,074	2,716
Operating income		(11,855)	(14,415)	(23,307)	(26,524)
Other expense (principally interest expense and other income (expense))		(134,101)	(88,871)	(479,774)	(191,947)
Cash capital expenditures		1,202	$ 624	2,396	$ 1,199
Assets		$ 450,665		$ 450,665		$ 139,210

[1] Includes non-cash compensation of $18,131 and $24,131 for the three months ended June 30, 2020 and 2019, respectively, and $33,684 and $46,736 for the six months ended June 30, 2020 and 2019, respectively.