Segment Data - Segment Reporting Information Disclosure (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012	Dec. 31, 2012
Segment Reporting Information [Line Items]
Revenues	$ 313,071	$ 192,490
Cost of revenues	100,695	52,193
Depreciation, amortization and accretion	125,636	82,100
Operating income	56,765	40,289
Capital expenditures	246,401	76,299
Assets	6,449,885		6,595,617
Site Leasing Revenue [Member]
Segment Reporting Information [Line Items]
Revenues	273,504	172,923
Cost of revenues	68,101	35,407
Depreciation, amortization and accretion	124,608	81,326
Operating income	51,593	42,254
Capital expenditures	244,139	75,416
Assets	6,199,935		6,422,577
Site Development [Member]
Segment Reporting Information [Line Items]
Revenues	39,567	19,567
Cost of revenues	32,594	16,786
Depreciation, amortization and accretion	559	516
Operating income	4,482	55
Capital expenditures	1,808	513
Assets	67,172		58,804
Not Identified By Segment [Member]
Segment Reporting Information [Line Items]
Depreciation, amortization and accretion	469	258
Operating income	690	(2,020)
Capital expenditures	454	370
Assets	$ 182,778		$ 114,236