Debt - Schedule of Cash and Non-Cash Interest Expense (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Debt Instrument [Line Items]
Cash Interest	$ 62,987	$ 50,578	$ 185,569	$ 136,728
Non-cash Interest	9,642	17,874	39,151	52,281
1.875% Convertible Senior Notes due 2013 [Member]
Debt Instrument [Line Items]
Cash Interest		2,508	2,670	7,523
Non-cash Interest		9,339	10,434	27,375
4.0% Convertible Senior Notes due 2014 [Member]
Debt Instrument [Line Items]
Cash Interest	4,999	5,000	14,999	15,000
Non-cash Interest	9,570	8,412	28,446	24,448
8.0% Senior Notes due 2016 [Member]
Debt Instrument [Line Items]
Cash Interest		3,142		15,867
Non-cash Interest		35		174
8.25% Senior Notes [Member]
Debt Instrument [Line Items]
Cash Interest	5,027	5,027	15,082	18,150
Non-cash Interest	46	42	135	149
5.625% Senior Notes [Member]
Debt Instrument [Line Items]
Cash Interest	7,031	234	21,094	234
5.75% Senior Notes [Member]
Debt Instrument [Line Items]
Cash Interest	11,500	10,094	34,500	10,094
2010 Secured Tower Revenue Securities [Member]
Debt Instrument [Line Items]
Cash Interest	14,349	14,344	43,037	43,032
2012 Secured Tower Revenue Securities [Member]
Debt Instrument [Line Items]
Cash Interest	4,521	2,612	13,564	2,612
2013 Secured Tower Revenue Securities [Member]
Debt Instrument [Line Items]
Cash Interest	10,804		19,588
Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Cash Interest	856	849	3,338	3,558
2011 Term Loan [Member]
Debt Instrument [Line Items]
Cash Interest	1,730	4,743	8,802	14,163
Non-cash Interest	16	45	85	134
2012-1 Term Loan A [Member]
Debt Instrument [Line Items]
Cash Interest	1,123	1,403	3,516	2,262
2012-2 Term Loan B [Member]
Debt Instrument [Line Items]
Cash Interest	1,054	94	5,362	94
Non-cash Interest	10	1	51	1
Mobilitie Bridge Loan [Member]
Debt Instrument [Line Items]
Cash Interest		499		4,239
Other [Member]
Debt Instrument [Line Items]
Cash Interest	$ (7)	$ 29	$ 17	$ (100)