v2.4.0.8

Debt (Consolidated Debt) (Details) (USD $)	Mar. 31, 2014		Dec. 31, 2013
Debt Instrument [Line Items]
Total debt	$ 2,941,276,000		$ 2,685,287,000
Weighted-Average Interest Rate	5.20%	[1]
Debt Instrument, Face Amount	2,900,000,000		2,700,000,000
Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Total debt	0		0
Weighted-Average Interest Rate	0.00%	[1]
Senior Notes [Member] | 6.45% Notes Due 2014 [Member]
Debt Instrument [Line Items]
Total debt	249,988,000		249,971,000
Weighted-Average Interest Rate	6.30%	[1]
Debt Instrument, Face Amount	250,000,000.0
Debt Instrument, Interest Rate, Stated Percentage	6.45%
Senior Notes [Member] | 5.65% Notes Due 2016 [Member]
Debt Instrument [Line Items]
Total debt	251,076,000		251,183,000
Weighted-Average Interest Rate	5.70%	[1]
Debt Instrument, Face Amount	250,000,000.0
Debt Instrument, Interest Rate, Stated Percentage	5.65%
Senior Notes [Member] | 6.40% Notes Due 2018 [Member]
Debt Instrument [Line Items]
Total debt	258,829,000		259,346,000
Weighted-Average Interest Rate	5.40%	[1]
Debt Instrument, Face Amount	250,000,000.0
Debt Instrument, Interest Rate, Stated Percentage	6.40%
Senior Notes [Member] | 6.55% Notes Due 2019 [Member]
Debt Instrument [Line Items]
Total debt	570,613,000		571,515,000
Weighted-Average Interest Rate	5.70%	[1]
Debt Instrument, Face Amount	550,000,000.0
Debt Instrument, Interest Rate, Stated Percentage	6.55%
Senior Notes [Member] | 4.25% Notes Due 2021 [Member]
Debt Instrument [Line Items]
Total debt	556,988,000		557,213,000
Weighted-Average Interest Rate	4.00%	[1]
Debt Instrument, Face Amount	550,000,000.0
Debt Instrument, Interest Rate, Stated Percentage	4.25%
Senior Notes [Member] | 6.40% Notes Due 2037 [Member]
Debt Instrument [Line Items]
Total debt	249,003,000		248,998,000
Weighted-Average Interest Rate	6.40%	[1]
Debt Instrument, Face Amount	250,000,000.0
Debt Instrument, Interest Rate, Stated Percentage	6.40%
Senior Notes [Member] | 4.20% Notes Due 2042 [Member]
Debt Instrument [Line Items]
Total debt	248,384,000		248,377,000
Weighted-Average Interest Rate	4.20%	[1]
Debt Instrument, Face Amount	250,000,000.0
Debt Instrument, Interest Rate, Stated Percentage	4.20%
Senior Notes [Member] | 5.15% Notes Due 2043 [Member]
Debt Instrument [Line Items]
Total debt	556,395,000		298,684,000
Weighted-Average Interest Rate	5.20%	[1]
Debt Instrument, Face Amount	$ 550,000,000.0
Debt Instrument, Interest Rate, Stated Percentage	5.15%
[1] Weighted-average interest rate includes the amortization/accretion of discounts and premiums and the amortization/accretion of gains and losses realized on historical cash flow and fair value hedges on interest expense.

X

- Definition

Face (par) amount of debt instrument at time of issuance.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 835

-SubTopic 30

-Section 45

-Paragraph 2

-URI http://asc.fasb.org/extlink&oid=6451184&loc=d3e28551-108399



Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 835

-SubTopic 30

-Section 55

-Paragraph 8

-URI http://asc.fasb.org/extlink&oid=6584090&loc=d3e28878-108400

+ Details

Name:	us-gaap_DebtInstrumentFaceAmount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

X

- Definition

Contractual interest rate for funds borrowed, under the debt agreement.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 22

-Article 5



Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.22(a)(1))

-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

+ Details

Name:	us-gaap_DebtInstrumentInterestRateStatedPercentage
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

X

- Details

Name:	us-gaap_DebtInstrumentLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

X

- Definition

Carrying amount of long-term debt, net of unamortized discount or premium, including current and noncurrent amounts. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 03

-Paragraph 16

-Article 7



Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.22)

-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682



Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 942

-SubTopic 210

-Section S99

-Paragraph 1

-Subparagraph (SX 210.9-03.16)

-URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878



Reference 4: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 03

-Paragraph 16

-Article 9



Reference 5: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 20, 22

-Article 5



Reference 6: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 944

-SubTopic 210

-Section S99

-Paragraph 1

-Subparagraph (SX 210.7-03.16)

-URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910

+ Details

Name:	us-gaap_LongTermDebt
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

X

- Definition

Weighted average interest rate of long-term debt outstanding.

+ References

No definition available.

+ Details

Name:	us-gaap_LongtermDebtWeightedAverageInterestRate
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant