Lines of Credit and Financing Arrangements (Details Textual 2) (USD $) In Millions	6 Months Ended
Jun. 30, 2011
Lines of Credit and Financing Arrangements (Textuals) [Abstract]
Committed standby letters of credit	77.5
Borrowing under swing line loan	29.0
Domestic revolving credit facility [Member]
Lines of Credit and Financing Arrangements (Textuals) [Abstract]
Swingline loans facility	650.0
Borrowing under swing line loan	354.0
Available for future borrowings	218.5
Line of Credit [Member]
Lines of Credit and Financing Arrangements (Textuals) [Abstract]
Default long term debt description of violation or event of default of revolving credit facility	Cross default under our revolving credit facility could occur if: • We fail to pay any principal or interest when due on any other indebtedness or receivables securitization of at least $40.0 million; or • We are in default in the performance of, or compliance with any term of any other indebtedness or receivables securitization in an aggregate principal amount of at least $40.0 million, or any other condition exists which would give the holders the right to declare such indebtedness due and payable prior to its stated maturity

Lines of Credit and Financing Arrangements.

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- Definition

Revolving Credit facility committed to standby letters of credit.

+ Details

Name:	lii_RevolvingCreditFacilityCommittedToStandbyLettersOfCredit
Namespace Prefix:	lii
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Discussion of the facts and amounts pertaining to each failure to comply with an affirmative or negative covenant of a long-term debt instrument, including violating payment terms or an inability to meet certain minimum financial requirements or achieve or maintain certain financial ratios. The discussion should also include whether or not the failure can and will be overcome and a description of the terms of any waivers, including the amount of the waiver and the period of time covered by the waiver, and if reclassification of long-term debt to current has been made in the current balance sheet.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 129
-Paragraph 4

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Section 08
-Paragraph c
-Article 4

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 129
-Paragraph 2

+ Details

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- Definition

Amount borrowed under the credit facility as of the balance-sheet date.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Section 02
-Paragraph 19, 22
-Article 5

+ Details

Name:	us-gaap_LineOfCreditFacilityAmountOutstanding
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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount of current borrowing capacity under the credit facility considering any current restrictions on the amount that could be borrowed (for example, borrowings may be limited by the amount of current assets), but without considering any amounts currently outstanding under the facility.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Section 02
-Paragraph 19, 22
-Article 5

+ Details

Name:	us-gaap_LineOfCreditFacilityCurrentBorrowingCapacity
Namespace Prefix:	us-gaap
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Maximum borrowing capacity under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 129
-Paragraph 2, 4

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Section 02
-Paragraph 19, 22
-Article 5

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant