Net Earnings per Limited Partner Common Unit (Details) (USD $) In Millions, except Per Share data, unless otherwise specified	3 Months Ended
Mar. 31, 2013	Mar. 31, 2012
Basic earnings per common unit:
Net earnings	$ 166.8	$ 124.2
Net earnings allocable to General Partner	(73.0)	(53.1)
Weighted average units outstanding	18.5	18.5
Net earnings per common unit (in dollars per unit)	$ 4.98	$ 3.78
Dilutive TNCLP units outstanding	0	0
Class B Common Units
Basic earnings per common unit:
Net earnings allocated	1.6	1.2
Common Units
Basic earnings per common unit:
Net earnings allocated	$ 92.2	$ 69.9

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

The portion of profit or loss for the period which is attributable to the parent.

+ References

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

-Publisher AICPA

-Name Accounting Research Bulletin (ARB)

-Number 51

-Paragraph 38

-Subparagraph a

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

+ Details

Name:	us-gaap_IncomeLossAttributableToParent
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Aggregate amount of net income allocated to general partners.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 505

-SubTopic 10

-Section S99

-Paragraph 5

-URI http://asc.fasb.org/extlink&oid=6959260&loc=d3e187171-122770

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

-Publisher SEC

-Name Staff Accounting Bulletin (SAB)

-Number Topic 4

-Section F

+ Details

Name:	us-gaap_NetIncomeLossAllocatedToGeneralPartners
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Aggregate amount of net income allocated to limited partners.

+ References

+ Details

Name:	us-gaap_NetIncomeLossAllocatedToLimitedPartners
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Net income (loss) allocated to each outstanding limited partnership unit.

+ References

+ Details

Name:	us-gaap_NetIncomeLossPerOutstandingLimitedPartnershipUnit
Namespace Prefix:	us-gaap_
Data Type:	us-types:perUnitItemType
Balance Type:	na
Period Type:	duration

- Definition

Weighted average number of limited partnership units outstanding determined by relating the portion of time within a reporting period that general partnership units have been outstanding to the total time in that period.

+ References

+ Details

Name:	us-gaap_WeightedAverageLimitedPartnershipUnitsOutstanding
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

- Definition

Weighted average number of limited partnership units outstanding determined by relating the portion of time within a reporting period that limited partnership units have been outstanding to the total time in that period. Used in the calculation of diluted net income or loss per limited partnership unit.

+ References

+ Details

Name:	us-gaap_WeightedAverageLimitedPartnershipUnitsOutstandingDiluted
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration