Long-Term Debt (Details)	12 Months Ended						12 Months Ended							12 Months Ended		12 Months Ended		12 Months Ended		12 Months Ended		12 Months Ended		12 Months Ended		12 Months Ended		12 Months Ended		12 Months Ended		12 Months Ended		12 Months Ended		12 Months Ended
	Dec. 31, 2014 USD ($)	Dec. 31, 2013 USD ($)	Dec. 31, 2012 USD ($)	Dec. 31, 2011 USD ($)	Dec. 31, 2013 Canadian Dollar Letter of Credit Facility Due 2018 [Member] USD ($)	Dec. 31, 2013 Canadian Dollar Letter of Credit Facility Due 2018 [Member] CAD	Dec. 31, 2013 Uncommitted Credit Facility [Member] USD ($)	Dec. 31, 2012 Uncommitted Credit Facility [Member] USD ($)	Dec. 31, 2013 Commercial Paper [Member] USD ($)	Dec. 31, 2012 Commercial Paper [Member] USD ($)	Dec. 31, 2013 Revolving Credit Agreement 2011 [Member] USD ($)	Dec. 31, 2013 Senior Notes Due 2013 [Member] USD ($)	Dec. 31, 2012 Senior Notes Due 2013 [Member] USD ($)	Dec. 31, 2013 Floating Rate Senior Notes Due 2014 [Member] USD ($)	Dec. 31, 2012 Floating Rate Senior Notes Due 2014 [Member] USD ($)	Dec. 31, 2013 Senior Notes Due 2015 [Member] USD ($)	Dec. 31, 2012 Senior Notes Due 2015 [Member] USD ($)	Dec. 31, 2013 Senior Notes Due 2016 [Member] USD ($)	Dec. 31, 2012 Senior Notes Due 2016 [Member] USD ($)	Dec. 31, 2013 Senior Notes Due 2017 [Member] USD ($)	Dec. 31, 2012 Senior Notes Due 2017 [Member] USD ($)	Dec. 31, 2013 Senior Notes Due 2018 [Member] USD ($)	Dec. 31, 2012 Senior Notes Due 2018 [Member] USD ($)	Dec. 31, 2013 Senior Notes Due 2019 [Member] USD ($)	Dec. 31, 2012 Senior Notes Due 2019 [Member] USD ($)	Dec. 31, 2013 Senior Notes Due 2020 [Member] USD ($)	Dec. 31, 2012 Senior Notes Due 2020 [Member] USD ($)	Dec. 31, 2013 Senior Notes Due 2021 [Member] USD ($)	Dec. 31, 2012 Senior Notes Due 2021 [Member] USD ($)	Dec. 31, 2013 Senior Notes Due 2023 [Member] USD ($)	Dec. 31, 2012 Senior Notes Due 2023 [Member] USD ($)	Dec. 31, 2013 Senior Notes Due 2028 [Member] USD ($)	Dec. 31, 2012 Senior Notes Due 2028 [Member] USD ($)	Dec. 31, 2013 Subsidiary Debt Due 2014 [Member] USD ($)	Dec. 31, 2012 Subsidiary Debt Due 2014 [Member] USD ($)	Dec. 31, 2013 Subsidiary Debt Due 2014, Canadian Dollar Equivalent [Member] CAD
Debt Instrument Table [Line Items]
Total Long-Term Debt		$ 5,890,000,000	$ 6,290,000,000									$ 0	$ 400,000,000	$ 350,000,000	$ 350,000,000	$ 500,000,000	$ 500,000,000	$ 400,000,000	$ 400,000,000	$ 600,000,000	$ 600,000,000	$ 350,000,000	$ 350,000,000	$ 900,000,000	$ 900,000,000	$ 500,000,000	$ 500,000,000	$ 750,000,000	$ 750,000,000	$ 1,250,000,000	$ 1,250,000,000	$ 140,000,000	$ 140,000,000	$ 150,000,000	$ 150,000,000
Capital Lease Obligation		57,187,000	62,968,000
Less: Current Portion of Long-Term Debt		6,579,000	406,579,000
Unamortized Debt Discount		33,966,000	40,787,000
Subsidiary Debt Due 2014 (Canadian)																																				201,300,000
Total Long-Term Debt, Net		5,906,642,000	5,905,602,000
Interest Rate - Canadian Subsidiary Note																																				5.275%
Debt Instrument Issuance [Abstract]
Debt Instrument Offering Date																														Sep. 10, 2012
Debt Instrument, Maturity Date																																				Mar. 15, 2014
Debt Instrument Issuance Face Amount																														1,250,000,000				150,000,000
Debt Instrument Issuance Interest Rate												6.125%				2.95%		2.50%		5.875%		6.875%		5.625%		4.40%		4.10%		2.625%		6.65%		4.75%
Debt Instrument, Maturity Years												2013		2014		2015		2016		2017		2018		2019		2020		2021		2023		2028		2014
Debt Instrument Frequency of Periodic Payment																														semi-annually
Proceeds From Issuance of Senior Long-Term Debt																														1,234,000,000
Effective Interest Rate (in hundredths)																														2.784%
Long-Term Debt by Maturity [Abstract]
Aggregate annual maturity of long-term debt (excluding capital lease obligations) in 2014		500,000,000
Aggregate annual maturity of long-term debt (excluding capital lease obligations) in 2015		500,000,000
Aggregate annual maturity of long-term debt (excluding capital lease obligations) in 2016		400,000,000
Aggregate annual maturity of long-term debt (excluding capital lease obligations) in 2017		600,000,000
Aggregate annual maturity of long-term debt (excluding capital lease obligations) in 2018		350,000,000
Line of Credit Facility [Line Items]
Long-Term Debt Repayments	350,000,000	400,000,000	0	220,000,000
Average Borrowings Outstanding							0	41,000,000	37,000,000	236,000,000
Weighted average interest rate (in hundredths)								0.70%	0.30%	0.45%
Line of Credit Facility, Expiration Date											Oct. 11, 2016
Restricted Cash					66,000,000	70,000,000
Maximum borrowing capacity						160,000,000					$ 2,000,000,000
Eurodollar rate at period end (in hundredths)											1.04%
Base rate at period end (in hundredths)											3.25%
Maximum total debt-to-total capitalization ratio allowed under financial covenant (in hundredths)											65.00%