Debt (Details) (USD $)	3 Months Ended			9 Months Ended					3 Months Ended		3 Months Ended		1 Months Ended		3 Months Ended				3 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Jun. 30, 2013	Sep. 30, 2014	Sep. 30, 2013	Apr. 15, 2013	Mar. 29, 2013	Sep. 30, 2014 Revolving Credit Facility [Member]	Mar. 31, 2013 2010 Revolving Credit Facility [Member]	Dec. 31, 2012 2010 Revolving Credit Facility [Member]	Mar. 31, 2013 Private Placement [Member]	Mar. 29, 2013 Private Placement [Member]	Jul. 31, 2013 Term Loan [Member]	Mar. 31, 2013 Term Loan [Member]	Jun. 30, 2014 Term Loan [Member]	Mar. 31, 2013 Term Loan [Member]	Sep. 30, 2012 Term Loan [Member]	Jun. 30, 2012 Term Loan [Member]	Jun. 30, 2014 Long-term Debt [Member] Term Loan [Member]	Jun. 30, 2013 Five Point Six Two Five Percent Notes, Due March Two Thousand Fourteen [Member]	Jun. 30, 2009 Five Point Six Two Five Percent Notes, Due March Two Thousand Fourteen [Member]	Jun. 30, 2009 Six Point Five Percent Notes Due March Two Thousand Nineteen [Member]	Mar. 31, 2008 Four Point Eight Percent Notes Due March Two Thousand Thirteen [Member]	Mar. 31, 2008 Five Point Seven Five Percent Notes, Due March Two Thousand Eighteen [Member]	Jun. 30, 2003 Four Point Two Percent Notes, Due July Two Thousand Eighteen [Member]	May 31, 2003 Four Point Six Two Five Percent Notes, Due May Two Thousand Thirteen [Member]	Mar. 31, 2013 Two Point Three Seven Five Percent Notes, Due March Two Thousand Sixteen [Member]	Mar. 31, 2013 Four Point Six Zero Percent Notes, Due March Two Thousand Twenty [Member]	Mar. 31, 2013 Five Point Zero Percent Notes, Due March Two Thousand Twenty-Three [Member]	Mar. 31, 2013 Six Point Nine Five Percent Notes, Due March Two Thousand Forty-Three [Member]
Debt Instrument [Line Items]
Line of credit facility								$ 1,000,000,000		$ 1,000,000,000								$ 500,000,000
Write off of Deferred Debt Issuance Cost									1,200,000		3,400,000									1,100,000
Commercial Paper								0
Debt Instrument, Interest Rate, Stated Percentage																					5.625%	6.50%	4.80%	5.75%	4.20%	4.625%	2.375%	4.60%	5.00%	6.95%
Debt Instrument, Face Amount																					500,000,000	350,000,000	250,000,000	250,000,000	250,000,000	125,000,000	250,000,000	500,000,000	500,000,000	250,000,000
2014 Notes prepayment percent						100.00%
2014 Notes accrued interest to be paid April 2013						3,400,000
2014 Notes make whole premium						21,700,000
2014 Notes acceleration of interest-rate swap gain			9,800,000
Loss on extinguishment of debt	0	0		0	86,000,000						71,400,000					1,600,000				13,000,000
Limits of subsidiary debt plus existing at February 28, 2013								500,000,000
Minimum Compliance Of Interest Coverage Ratio Numerator								4
Minimum Compliance Interest Coverage Ratio Denominator								1
Maximum leverage ratio numerator Sep 2014								3.75
Maximum leverage ratio denominator Sep 2014								1
Maximum leverage ratio numerator Dec 2014								3.5
Maximum leverage ratio denominator Dec 2014								1
Interest coverage ratio add back maximum of restructuring or legal or regulatory action								400,000,000
Revolving credit facility draw down amount without violating covenant	1,000,000,000			1,000,000,000
Term loan incremental draw down																	50,000,000
Repayments of Long-term Debt													117,500,000	380,000,000	52,500,000				39,400,000
Private Placement Notes												535,000,000
Private notes make whole premium							68,000,000
Commercial paper program								$ 1,000,000,000
Credit ratings				Our long-term credit ratings are Ba1 (Stable Outlook) with Moody's and BB (Negative Outlook) with Fitch, which are below investment grade, and BBB- (Negative Outlook) with S&P, which is on the low end of investment grade.