Debt - Carrying Values of Debt (Detail) (USD $) In Thousands, unless otherwise specified	1 Months Ended			1 Months Ended	3 Months Ended		1 Months Ended	3 Months Ended		3 Months Ended		3 Months Ended		3 Months Ended		3 Months Ended		3 Months Ended		3 Months Ended		3 Months Ended		3 Months Ended		3 Months Ended		3 Months Ended
	Apr. 18, 2013	Mar. 31, 2013	Dec. 31, 2012	May 16, 2008 1.875% Convertible Senior Notes due 2013 [Member]	Mar. 31, 2013 1.875% Convertible Senior Notes due 2013 [Member]	Dec. 31, 2012 1.875% Convertible Senior Notes due 2013 [Member]	Apr. 24, 2009 4.0% Convertible Senior Notes due 2014 [Member]	Mar. 31, 2013 4.0% Convertible Senior Notes due 2014 [Member]	Dec. 31, 2012 4.0% Convertible Senior Notes due 2014 [Member]	Mar. 31, 2013 4.254% Secured Tower Revenue Securities Series 2010-1 [Member]	Dec. 31, 2012 4.254% Secured Tower Revenue Securities Series 2010-1 [Member]	Mar. 31, 2013 5.101% Secured Tower Revenue Securities Series 2010-2 [Member]	Dec. 31, 2012 5.101% Secured Tower Revenue Securities Series 2010-2 [Member]	Mar. 31, 2013 2.933% Secured Tower Revenue Securities Series 2012-1 [Member]	Dec. 31, 2012 2.933% Secured Tower Revenue Securities Series 2012-1 [Member]	Mar. 31, 2013 8.25% Senior Notes [Member]	Dec. 31, 2012 8.25% Senior Notes [Member]	Mar. 31, 2013 5.625% Senior Notes [Member]	Dec. 31, 2012 5.625% Senior Notes [Member]	Mar. 31, 2013 5.75% Senior Notes [Member]	Dec. 31, 2012 5.75% Senior Notes [Member]	Mar. 31, 2013 Revolving Credit Facility [Member]	Dec. 31, 2012 Revolving Credit Facility [Member]	Mar. 31, 2013 2011 Term Loan B [Member]	Dec. 31, 2012 2011 Term Loan B [Member]	Mar. 31, 2013 2012-1 Term Loan A [Member]	Dec. 31, 2012 2012-1 Term Loan A [Member]	Mar. 31, 2013 2012-2 Term Loan B [Member]	Dec. 31, 2012 2012-2 Term Loan B [Member]
Debt Instrument [Line Items]
Debt instrument, principal balance		$ 5,430,247	$ 5,440,073		$ 463,514	$ 468,836		$ 499,983	$ 499,987	$ 680,000	$ 680,000	$ 550,000	$ 550,000	$ 610,000	$ 610,000	$ 243,750	$ 243,750	$ 500,000	$ 500,000	$ 800,000	$ 800,000	$ 100,000	$ 100,000	$ 491,250	$ 492,500	$ 192,500	$ 195,000	$ 299,250	$ 300,000
Debt, Carrying Value		5,363,793	5,356,103		460,454	457,351		439,723	430,751	680,000	680,000	550,000	550,000	610,000	610,000	242,249	242,205	500,000	500,000	800,000	800,000	100,000	100,000	490,313	491,518	192,500	195,000	298,554	299,278
Less: current maturities of long-term debt		(478,454)	(475,351)
Total long-term debt, net of current maturities		$ 4,885,339	$ 4,880,752
Debt instrument, maturity date	May 01, 2013			May 01, 2013	May 01, 2013		Oct. 01, 2014	Oct. 01, 2014		Apr. 15, 2015		Apr. 17, 2017		Dec. 15, 2017		Aug. 15, 2019		Oct. 01, 2019		Jul. 15, 2020		May 09, 2017		Jun. 30, 2018		May 09, 2017		Sep. 28, 2019