Line of credit facility maximum borrowed amount paid.

No definition available.

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Period Type:	instant

- Definition

Percentage points added to the reference rate to compute the variable rate on the debt instrument.

+ References

No definition available.

+ Details

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Namespace Prefix:	us-gaap_
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- Definition

The reference rate for the variable rate of the debt instrument, such as LIBOR or the US Treasury rate and the maturity of the reference rate used, such as three months or six months LIBOR.

+ References

No definition available.

+ Details

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- Definition

Effective interest rate for the funds borrowed under the debt agreement considering interest compounding and original issue discount or premium.

+ 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 210.5-02.22(a)(1))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 2: 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

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Balance Type:	na
Period Type:	instant

- Definition

Amount of the required periodic payments applied to principal.

+ References

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- 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
-URI http://asc.fasb.org/extlink&oid=6451184&loc=d3e28541-108399

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=34725769&loc=d3e28878-108400

+ Details

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Balance Type:	debit
Period Type:	instant

- Definition

The carrying value as of the balance sheet date of the current and noncurrent portions of long-term obligations drawn from a line of credit, which is a bank's commitment to make loans up to a specific amount. Examples of items that might be included in the application of this element may consist of letters of credit, standby letters of credit, and revolving credit arrangements, under which borrowings can be made up to a maximum amount as of any point in time conditional on satisfaction of specified terms before, as of and after the date of drawdowns on the line. Includes short-term obligations that would normally be classified as current liabilities but for which (a) postbalance sheet date issuance of a long term obligation to refinance the short term obligation on a long term basis, or (b) the enterprise has entered into a financing agreement that clearly permits the enterprise to refinance the short-term obligation on a long term basis and the following conditions are met (1) the agreement does not expire within 1 year and is not cancelable by the lender except for violation of an objectively determinable provision, (2) no violation exists at the BS date, and (3) the lender has entered into the financing agreement is expected to be financially capable of honoring the agreement.

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

Reference 2: 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

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Section 02
-Paragraph 19, 20, 22
-Article 5

+ Details

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

- Definition

Date the credit facility terminates, in CCYY-MM-DD format.

+ References

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:dateItemType
Balance Type:	na
Period Type:	duration

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

+ Details

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Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- 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

+ Details

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

- Definition

Amount of the required periodic payment applied to principal.

+ References

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

The fee, expressed as a percentage of the line of credit facility, for available but unused credit capacity under the credit facility.

+ References

No definition available.

+ Details

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Balance Type:	na
Period Type:	duration

- Definition

The cash outflow paid to third parties in connection with debt origination, which will be amortized over the remaining maturity period of the associated long-term debt.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 15
-Subparagraph (e)
-URI http://asc.fasb.org/extlink&oid=56944662&loc=d3e3291-108585

+ Details

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Balance Type:	credit
Period Type:	duration

- Definition

The remaining balance of debt issuance expenses that were capitalized and are being amortized against income over the lives of the respective bond issues. This does not include the amounts capitalized as part of the cost of the utility plant or asset.

+ References

+ Details

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- Details

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- Details

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- Details

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- Details

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- Details

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Long-Term Debt (Details) - USD ($)		6 Months Ended		12 Months Ended	47 Months Ended
Long-Term Debt (Details) - USD ($)	Dec. 03, 2014	Jan. 31, 2016	Jan. 31, 2015	Dec. 31, 2015	Dec. 03, 2019	Sep. 29, 2011	Dec. 14, 2010
Line of Credit Facility [Line Items]
Debt issuance cost		$ 0	$ 955,000
Revolving Loan Facility [Member]
Line of Credit Facility [Line Items]
Maximum borrowing capacity							$ 100,000,000
Term Loan Facility [Member]
Line of Credit Facility [Line Items]
Maximum borrowing capacity						$ 500,000,000	400,000,000
Maturity date		Dec. 03, 2019
Alternative currency borrowing credit facility [Member]
Line of Credit Facility [Line Items]
Maximum borrowing capacity							100,000,000
Letter of Credit [Member]
Line of Credit Facility [Line Items]
Maximum borrowing capacity							$ 50,000,000
Credit Agreement [Member]
Line of Credit Facility [Line Items]
Line of credit facility amount paid	$ 275,000,000
Maturity date		Dec. 03, 2019
Credit Agreement [Member] \| Revolving Loan Facility [Member]
Line of Credit Facility [Line Items]
Maximum borrowing capacity	300,000,000
Outstanding borrowings	0	$ 68,000,000
Credit Agreement [Member] \| Revolving Loan Facility [Member] \| Minimum [Member]
Line of Credit Facility [Line Items]
Commitment fee percentage		0.20%
Credit Agreement [Member] \| Revolving Loan Facility [Member] \| Maximum [Member]
Line of Credit Facility [Line Items]
Commitment fee percentage		0.35%
Credit Agreement [Member] \| Term Loan Facility [Member]
Line of Credit Facility [Line Items]
Maximum borrowing capacity	300,000,000
Outstanding borrowings		$ 206,300,000
Maturity date		Dec. 31, 2015
Quarterly amortization for term loan				$ 18,800,000
LIBOR variable interest rate		LIBOR rate of 0.43% plus an applicable margin of 1.25%.
Note Purchase Agreement [Member]
Line of Credit Facility [Line Items]
Debt issuance cost		$ 2,100,000
Debt issuance fees		1,000,000
Reduction of long term debt		$ 1,100,000
Note Purchase Agreement [Member] \| Senior Notes [Member]
Line of Credit Facility [Line Items]
Debt instrument principal amount	400,000,000
Note Purchase Agreement [Member] \| Senior Notes, Series A [Member]
Line of Credit Facility [Line Items]
Maturity date		Dec. 03, 2024
Debt instrument principal amount	$ 100,000,000
Debt instrument, interest rate	4.07%
Note Purchase Agreement [Member] \| Senior Notes, Series B [Member]
Line of Credit Facility [Line Items]
Maturity date		Dec. 03, 2026
Debt instrument principal amount	$ 100,000,000
Debt instrument, interest rate	4.19%
Note Purchase Agreement [Member] \| Senior Notes, Series C [Member]
Line of Credit Facility [Line Items]
Maturity date		Dec. 03, 2027
Debt instrument principal amount	$ 100,000,000
Debt instrument, interest rate	4.25%
Note Purchase Agreement [Member] \| Senior Notes, Series D [Member]
Line of Credit Facility [Line Items]
Maturity date		Dec. 03, 2029
Debt instrument principal amount	$ 100,000,000
Debt instrument, interest rate	4.35%
Scenario, Forecast [Member] \| Credit Agreement [Member] \| Term Loan Facility [Member]
Line of Credit Facility [Line Items]
Quarterly amortization for term loan					$ 7,500,000
Federal Funds Effective Swap Rate [Member] \| Credit Agreement [Member] \| Revolving Loan Facility [Member]
Line of Credit Facility [Line Items]
Applicable interest rate added to reference rate in order to compute variable interest rate		0.50%
London Interbank Offered Rate (LIBOR) [Member] \| Credit Agreement [Member] \| Revolving Loan Facility [Member]
Line of Credit Facility [Line Items]
Applicable interest rate added to reference rate in order to compute variable interest rate		1.00%
London Interbank Offered Rate (LIBOR), Adjusted LIBOR One [Member] \| Credit Agreement [Member] \| Revolving Loan Facility [Member] \| Minimum [Member]
Line of Credit Facility [Line Items]
Applicable interest rate added to reference rate in order to compute variable interest rate		0.25%
London Interbank Offered Rate (LIBOR), Adjusted LIBOR One [Member] \| Credit Agreement [Member] \| Revolving Loan Facility [Member] \| Maximum [Member]
Line of Credit Facility [Line Items]
Applicable interest rate added to reference rate in order to compute variable interest rate		1.00%
London Interbank Offered Rate (LIBOR) Adjusted LIBOR Two [Member] \| Credit Agreement [Member] \| Revolving Loan Facility [Member] \| Minimum [Member]
Line of Credit Facility [Line Items]
Applicable interest rate added to reference rate in order to compute variable interest rate		1.25%
London Interbank Offered Rate (LIBOR) Adjusted LIBOR Two [Member] \| Credit Agreement [Member] \| Revolving Loan Facility [Member] \| Maximum [Member]
Line of Credit Facility [Line Items]
Applicable interest rate added to reference rate in order to compute variable interest rate		2.00%