Fair Value Measurements (Tables)

3 Months Ended

Mar. 31, 2014

Fair Value Measurements [Abstract]

Summary Of Fair Values, Principal Balances, And Carrying Values Of Company's Debt Instruments

	As of March 31, 2014						As of December 31, 2013
	Fair Value		Principal Balance		Carrying Value		Fair Value		Principal Balance		Carrying Value
	(in thousands)
4.000% Convertible Senior Notes due 2014	$	1,490,982	$	499,910	$	478,564	$	1,479,859	$	499,944	$	468,394
8.250% Senior Notes due 2019		258,375		243,750		242,435		262,031		243,750		242,387
5.625% Senior Notes due 2019		521,875		500,000		500,000		514,375		500,000		500,000
5.750% Senior Notes due 2020		835,000		800,000		800,000		832,000		800,000		800,000
4.254% 2010-1 Tower Securities		687,609		680,000		680,000		689,717		680,000		680,000
5.101% 2010-2 Tower Securities		589,243		550,000		550,000		586,586		550,000		550,000
2.933% 2012-1Tower Securities		619,217		610,000		610,000		604,736		610,000		610,000
2.240% 2013-1C Tower Securities		417,507		425,000		425,000		408,442		425,000		425,000
3.722% 2013-2C Tower Securities		557,267		575,000		575,000		530,098		575,000		575,000
3.598% 2013-1D Tower Securities		322,882		330,000		330,000		318,856		330,000		330,000
Revolving Credit Facility		—		—		—		215,000		215,000		215,000
2011 Term Loan		—		—		—		180,980		180,529		180,234
2012-1 Term Loan		182,044		182,500		182,500		184,538		185,000		185,000
2012-2 Term Loan		—		—		—		110,383		109,971		109,745
2014 Term Loan		1,500,000		1,500,000		1,496,047		—		—		—
BNDES Loans		212		212		212		5,847		5,847		5,847
Totals	$	7,982,213	$	6,896,372	$	6,869,758	$	6,923,448	$	5,910,041	$	5,876,607