Unamortized fair value premium as of the balance sheet date.

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- Definition

Amount equal to the present value (the principal) at the beginning of the lease term of minimum lease payments during the lease term (excluding that portion of the payments representing executory costs such as insurance, maintenance, and taxes to be paid by the lessor, together with any profit thereon) net of payments or other amounts applied to the principal through the balance sheet date.

+ 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

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-Name Accounting Standards Codification

-Topic 840

-SubTopic 30

-Section 50

-Paragraph 1

-Subparagraph (b)

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- 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

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

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- Definition

The amount of debt discount that was originally recognized at the issuance of the instrument that has yet to be amortized.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 835

-SubTopic 30

-Section 45

-Paragraph 1A

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- Definition

Amount as of the balance sheet date of the unamortized adjustment to the carrying value of an interest-bearing hedged item made under an effective fair value hedge that is amortized upon discontinuation of the fair value hedge.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 815

-SubTopic 25

-Section 35

-Paragraph 9

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- Definition

Amount of long-term debt, after unamortized discount or premium, scheduled to be repaid within one year or the normal operating cycle, if longer. 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 FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.19,20)

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-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

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-Paragraph 20

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-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

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-Paragraph 19

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- Definition

Carrying amount of long-term debt, net of unamortized discount or premium, excluding amounts to be repaid within one year or the normal operating cycle, if longer (current maturities). 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 02

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-Subparagraph (SX 210.5-02.22)

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- Definition

Including the current and noncurrent portions, aggregate carrying amount of all types of notes payable, as of the balance sheet date, with initial maturities beyond one year or beyond the normal operating cycle, if longer.

+ References

Reference 1: 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)

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-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 19, 20, 22

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-Topic 944

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-Subparagraph (SX 210.7-03.16)

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-Number 210

-Section 03

-Paragraph 13, 16

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DEBT (Details 1) (USD $) In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Aug. 31, 2014	Oct. 31, 2011	Jun. 30, 2013
Debt Instrument [Line Items]
Notes payable	$ 675.1us-gaap_NotesPayable	$ 691.0us-gaap_NotesPayable
Capital Lease Obligations	3.6us-gaap_CapitalLeaseObligations	4.1us-gaap_CapitalLeaseObligations
Current installments of long-term debt	16.4us-gaap_LongTermDebtCurrent	12.6us-gaap_LongTermDebtCurrent
Total long-term debt	658.7us-gaap_LongTermDebtNoncurrent	678.4us-gaap_LongTermDebtNoncurrent
Senior Term Loan Facility
Debt Instrument [Line Items]
Notes payable	149.1	0
Interest rate	1.66%
Variable -Rate Go Zone Bonds
Debt Instrument [Line Items]
Notes payable	50.0	50.0
Interest rate	1.31%	1.42%
Variable-Rate Recovery Zone Bonds
Debt Instrument [Line Items]
Notes payable	103.0	103.0
Interest rate	1.31%	1.42%
Industrial Development and Environmental Improvement Obligations
Debt Instrument [Line Items]
Notes payable	2.9	2.9
Interest rate	0.20%	0.22%
2022 Notes
Debt Instrument [Line Items]
Notes payable	200.0	200.0
Interest rate	5.50%	5.50%
Notes payable due 2016
Debt Instrument [Line Items]
Notes payable	128.7	131.1
Interest rate	6.75%	6.75%
SunBelt Notes
Debt Instrument [Line Items]
Notes payable	37.8	50.7
Interest rate	7.23%	7.23%
Unamortized fair value premium	0.5	0.8
Notes payable due 2019
Debt Instrument [Line Items]
Notes payable	0	149.2	150.0
Interest rate	0.00%	8.875%
Unamortized discount	0	0.8
Variable Interest Rate Swaps $125M
Debt Instrument [Line Items]
Deferred (Gain) Loss on Discontinuation of Fair Value Hedge	3.7	6.1		11.0
SunBelt Notes
Debt Instrument [Line Items]
Deferred (Gain) Loss on Discontinuation of Fair Value Hedge	$ 0.8	$ 1.2			$ 2.2