Goodwill and Other Intangible Assets - Summary of Intangible Assets (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Dec. 31, 2019
Finite Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 3,147,454	$ 3,142,112
Accumulated Amortization	2,176,264	2,149,868
Goodwill gross carrying amount	2,165,609	2,165,810
Goodwill accumulated amortization	253,536	253,536
Customer Lists and Contracts [Member]
Finite Lived Intangible Assets [Line Items]
Gross Carrying Amount	642,704	641,714
Accumulated Amortization	$ 545,239	539,405
Customer Lists and Contracts [Member] | Minimum [Member]
Finite Lived Intangible Assets [Line Items]
Estimated Life (Years)	7 years
Customer Lists and Contracts [Member] | Maximum [Member]
Finite Lived Intangible Assets [Line Items]
Estimated Life (Years)	10 years
Non-competition Agreements [Member]
Finite Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 66,069	66,014
Accumulated Amortization	$ 64,441	64,379
Non-competition Agreements [Member] | Minimum [Member]
Finite Lived Intangible Assets [Line Items]
Estimated Life (Years)	3 years
Non-competition Agreements [Member] | Maximum [Member]
Finite Lived Intangible Assets [Line Items]
Estimated Life (Years)	15 years
Site Locations [Member]
Finite Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 2,388,771	2,384,520
Accumulated Amortization	$ 1,529,296	1,509,335
Site Locations [Member] | Maximum [Member]
Finite Lived Intangible Assets [Line Items]
Estimated Life (Years)	15 years
Other [Member]
Finite Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 49,910	49,864
Accumulated Amortization	$ 37,288	$ 36,749
Other [Member] | Minimum [Member]
Finite Lived Intangible Assets [Line Items]
Estimated Life (Years)	2 years
Other [Member] | Maximum [Member]
Finite Lived Intangible Assets [Line Items]
Estimated Life (Years)	15 years