Long-Term Debt (Schedule Of Indebtedness) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended	12 Months Ended
	Mar. 31, 2013	Dec. 31, 2012	Mar. 31, 2012
Debt Instrument [Line Items]
Long-term debt	$ 7,753,948	$ 1,358,695
7 3/4% Senior Notes Due August 15, 2013 [Member]
Debt Instrument [Line Items]
Long-term debt	94,476	94,461
Interest rate	7.75%	7.75%
Maturity date	Aug. 15, 2013	Aug. 15, 2013
7% Senior Notes Due August 15, 2013 [Member]
Debt Instrument [Line Items]
Long-term debt	307,461	307,494
Interest rate	7.00%	7.00%
Maturity date	Aug. 15, 2013	Aug. 15, 2013
8 1/8% Senior Notes Due September 15, 2015 [Member]
Debt Instrument [Line Items]
Long-term debt	455,674	455,405
Interest rate	8.125%	8.125%
Maturity date	Sep. 15, 2015	Sep. 15, 2015
3 3/4% Convertible Senior Subordinated Notes Due April 15, 2014 [Member]
Debt Instrument [Line Items]
Long-term debt	97,581	97,581
Interest rate	3.75%	3.75%	3.75%
Maturity date	Apr. 15, 2014	Apr. 15, 2014
5.875% Senior Notes, due June 8, 2014 [Member]
Debt Instrument [Line Items]
Long-term debt	263,750
Interest rate	5.875%
Maturity date	Jun. 08, 2014
3.875% Senior Notes, due November 9, 2015 [Member]
Debt Instrument [Line Items]
Long-term debt	522,283
Interest rate	3.875%
Maturity date	Nov. 09, 2015
5.5% Senior Notes, due March 15, 2016 [Member]
Debt Instrument [Line Items]
Long-term debt	380,477
Interest rate	5.50%
Maturity date	Mar. 15, 2016
5.125% Senior Notes, due April 13, 2018 [Member]
Debt Instrument [Line Items]
Long-term debt	862,490
Interest rate	5.125%
Maturity date	Apr. 13, 2018
8.5% Senior Notes, due July 15, 2019 [Member]
Debt Instrument [Line Items]
Long-term debt	876,985
Interest rate	8.50%
Maturity date	Jul. 15, 2019
6.875% Senior Notes, due April 15, 2021 [Member]
Debt Instrument [Line Items]
Long-term debt	876,696
Interest rate	6.875%
Maturity date	Apr. 15, 2021
2.25% Euro Medium Term Notes, due July 13, 2022 [Member]
Debt Instrument [Line Items]
Long-term debt	4,576
Interest rate	2.25%
Maturity date	Jul. 13, 2022
6.45% Senior Debentures, due June 8, 2027 [Member]
Debt Instrument [Line Items]
Long-term debt	384,446
Interest rate	6.45%
Maturity date	Jun. 08, 2027
5.125% Senior Notes, due January 20, 2023 [Member]
Debt Instrument [Line Items]
Long-term debt	627,293
Interest rate	5.125%
Maturity date	Jan. 20, 2023
6.50% Senior Notes, due January 20, 2043 [Member]
Debt Instrument [Line Items]
Long-term debt	422,449
Interest rate	6.50%
Maturity date	Jan. 20, 2043
3.875% Convertible Senior Debentures, due November 1, 2029 [Member]
Debt Instrument [Line Items]
Long-term debt	350,537
Interest rate	3.875%
Maturity date	Nov. 01, 2029
6.25% Senior Debentures, due January 15, 2036 [Member]
Debt Instrument [Line Items]
Long-term debt	513,554
Interest rate	6.25%
Maturity date	Jan. 15, 2036
Secured credit facility, due August 26, 2014 [Member]
Debt Instrument [Line Items]
Long-term debt	260,000
Maturity date	Aug. 26, 2014
Term Loan [Member]
Debt Instrument [Line Items]
Long-term debt	277,500	296,000
Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Long-term debt	159,768	91,403
Other [Member]
Debt Instrument [Line Items]
Long-term debt	$ 15,952	$ 16,351