Debt - Schedule of Cash and Non-Cash Interest Expense (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
Debt Instrument [Line Items]
Cash Interest	$ 59,465	$ 42,248
Non-cash Interest	17,364	16,991
1.875% Convertible Senior Notes due 2013 [Member]
Debt Instrument [Line Items]
Cash Interest	2,120	2,508
Non-cash Interest	8,273	8,913
4.0% Convertible Senior Notes due 2014 [Member]
Debt Instrument [Line Items]
Cash Interest	5,000	5,000
Non-cash Interest	8,975	7,890
8.0% Senior Notes due 2016 [Member]
Debt Instrument [Line Items]
Cash Interest		7,500
Non-cash Interest		81
8.25% Senior Notes [Member]
Debt Instrument [Line Items]
Cash Interest	5,027	7,734
Non-cash Interest	44	62
5.625% Senior Notes [Member]
Debt Instrument [Line Items]
Cash Interest	7,031
Non-cash Interest
5.75% Senior Notes [Member]
Debt Instrument [Line Items]
Cash Interest	11,500
Non-cash Interest
2010 Secured Tower Revenue Securities [Member]
Debt Instrument [Line Items]
Cash Interest	14,344	14,344
Non-cash Interest
2012 Secured Tower Revenue Securities [Member]
Debt Instrument [Line Items]
Cash Interest	4,521
Non-cash Interest
Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Cash Interest	1,362	515
Non-cash Interest
2011 Term Loan [Member]
Debt Instrument [Line Items]
Cash Interest	4,617	4,715
Non-cash Interest	45	45
2012-1 Term Loan A [Member]
Debt Instrument [Line Items]
Cash Interest	1,200
Non-cash Interest
2012-2 Term Loan B [Member]
Debt Instrument [Line Items]
Cash Interest	2,812
Non-cash Interest	27
Other [Member]
Debt Instrument [Line Items]
Cash Interest	(69)	(68)
Non-cash Interest