Debt Instrument, Covenant, Consolidated Interest Coverage Ratio, Minimum

No definition available.

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- Definition

Debt Instrument, Covenant, Consolidated Leverage Ratio, Scenario Four, Maximum

+ References

No definition available.

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- Definition

Debt Instrument, Covenant, Consolidated Leverage Ratio, Scenario One, Maximum

+ References

No definition available.

+ Details

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- Definition

Debt Instrument, Covenant, Consolidated Leverage Ratio, Scenario Three, Maximum

+ References

No definition available.

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- Definition

Debt Instrument, Covenant, Consolidated Leverage Ratio, Scenario Two, Maximum

+ References

No definition available.

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- Definition

Debt Instrument, Covenant, Consolidated Senior Secured Leverage Ratio, Maximum

+ References

No definition available.

+ Details

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- Definition

Debt Instrument, Decrease in Overall Borrowing Costs, Percentage

+ References

No definition available.

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- Definition

Line of Credit Facility, Accordion Feature, Higher Borrowing Capacity Option

+ References

No definition available.

+ Details

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Period Type:	instant

- Definition

Proceeds from Line of Credit, Additional Borrowings

+ References

No definition available.

+ Details

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Balance Type:	debit
Period Type:	duration

- 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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- 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 55
-Paragraph 8
-URI http://asc.fasb.org/extlink&oid=64930739&loc=d3e28878-108400

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=64930785&loc=d3e28551-108399

+ Details

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- 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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- Definition

Period of time between issuance and maturity of debt instrument, in PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

No definition available.

+ Details

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- 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 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 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 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

+ Details

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- Definition

The fee, expressed as a percentage of the line of credit facility, for the line of credit facility regardless of whether the facility has been used.

+ References

No definition available.

+ Details

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- 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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- Definition

The carrying value as of the balance sheet date of the current portion 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(13))
-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 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(19))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

+ Details

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- Definition

Amount, after unamortized (discount) premium and debt issuance costs, of long-term debt, classified as current. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.

+ References

+ Details

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- Definition

Amount after unamortized (discount) premium and debt issuance costs of long-term debt classified as noncurrent and excluding amounts 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

+ Details

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- Definition

Amount of cash inflow from contractual arrangement with the lender, including but not limited to, letter of credit, standby letter of credit and revolving credit arrangements.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 14
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=98514028&loc=d3e3255-108585

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 235
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08.(f))
-URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e23780-122690

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Balance Type:	debit
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- Definition

Amount of cash outflow for payment of an obligation from a lender, including but not limited to, letter of credit, standby letter of credit and revolving credit arrangements.

+ 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 (b)
-URI http://asc.fasb.org/extlink&oid=98514028&loc=d3e3291-108585

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 235
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08.(f))
-URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e23780-122690

+ Details

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- Details

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Long-term Debt and Credit Agreement - Narrative (Details)		3 Months Ended
	Feb. 21, 2018 USD ($)	Mar. 31, 2018 USD ($)	Mar. 31, 2017 USD ($)	Feb. 20, 2018 USD ($)	Dec. 31, 2017 USD ($)	Sep. 30, 2016 USD ($)
Debt Instrument [Line Items]
Line of credit, short term		$ 37,600,000
Line of credit, long term		192,400,000
Long-term line of credit		230,000,000
Proceeds from lines of credit		246,000,000	$ 167,500,000
Percentage decrease in overall borrowing costs	0.50%
Line of credit facility, accordion feature, higher borrowing capacity option	$ 175,000,000
Repayments of lines of credit		16,000,000	$ 167,500,000
Letter of credit agreements outstanding		37,600,000			$ 0
Bi-lateral Letter of Credit Agreements [Member]
Debt Instrument [Line Items]
Letter of credit agreements outstanding		10,500,000
Term Loan [Member]
Debt Instrument [Line Items]
Debt instrument, aggregate principal amount						$ 270,000,000
Long-term line of credit				$ 267,000,000
Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Debt instrument, aggregate principal amount						$ 155,000,000
Letter of credit agreements outstanding		1,300,000
Amended and Restated Credit Agreement [Member]
Debt Instrument [Line Items]
Debt instrument, covenant, consolidated senior secured leverage ratio, maximum	1.75
Debt instrument, covenant, consolidated interest coverage ratio, minimum	3.00
Debt instrument, covenant, consolidated leverage ratio, scenario one, maximum	3.50
Debt instrument, covenant, consolidated leverage ratio, scenario two, maximum	3.25
Debt instrument, covenant, consolidated leverage ratio, scenario three, maximum	3.00
Debt instrument, covenant, consolidated leverage ratio, scenario four, maximum	2.75
Letter of Credit [Member]
Debt Instrument [Line Items]
Letter of credit agreements outstanding		11,800,000
Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Line of credit, short term		37,600,000
Line of credit, long term		192,400,000
Long-term line of credit		230,000,000
Proceeds from lines of credit	$ 242,000,000
Debt instrument, term	5 years
Additional borrowings from line of credit		4,000,000
Repayments of lines of credit		$ 16,000,000
Revolving Credit Facility [Member] \| Senior Secured Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Maximum borrowing capacity	$ 425,000,000
Letter of Credit [Member]
Debt Instrument [Line Items]
Maximum borrowing capacity	40,000,000
Bridge Loan [Member]
Debt Instrument [Line Items]
Maximum borrowing capacity	$ 40,000,000
Minimum [Member] \| Amended and Restated Credit Agreement [Member]
Debt Instrument [Line Items]
Commitment fee percentage	0.20%
Maximum [Member] \| Amended and Restated Credit Agreement [Member]
Debt Instrument [Line Items]
Commitment fee percentage	0.40%
Base Rate [Member] \| Amended and Restated Credit Agreement [Member]
Debt Instrument [Line Items]
Debt instrument, basis spread on variable rate	0.75%
Base Rate [Member] \| Minimum [Member] \| Amended and Restated Credit Agreement [Member]
Debt Instrument [Line Items]
Debt instrument, basis spread on variable rate	0.50%
Base Rate [Member] \| Maximum [Member] \| Amended and Restated Credit Agreement [Member]
Debt Instrument [Line Items]
Debt instrument, basis spread on variable rate	1.50%
Eurodollar [Member] \| Amended and Restated Credit Agreement [Member]
Debt Instrument [Line Items]
Debt instrument, basis spread on variable rate	1.75%
Commitment fee percentage	0.25%
Eurodollar [Member] \| Minimum [Member] \| Amended and Restated Credit Agreement [Member]
Debt Instrument [Line Items]
Debt instrument, basis spread on variable rate	1.50%
Eurodollar [Member] \| Maximum [Member] \| Amended and Restated Credit Agreement [Member]
Debt Instrument [Line Items]
Debt instrument, basis spread on variable rate	2.50%