Debt instrument covenant interest coverage ratio.

No definition available.

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- Definition

Debt instrument covenant leverage ratio.

+ References

No definition available.

+ Details

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- Definition

Debt instrument fixed portion of outstanding debt percentage.

+ References

No definition available.

+ Details

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Period Type:	duration

- Definition

Interest Expense Amortization Period

+ References

No definition available.

+ Details

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Balance Type:	na
Period Type:	duration

- Definition

Line of credit facility issuance fee percentage.

+ References

No definition available.

+ Details

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Balance Type:	na
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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Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- 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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Balance Type:	credit
Period Type:	instant

- 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

Difference between the fair value of payments made and the carrying amount of debt which is extinguished prior to maturity.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 50
-Section 40
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=49170532&loc=d3e12317-112629

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 28
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=98514028&loc=d3e3602-108585

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 50
-Section 40
-Paragraph 4
-URI http://asc.fasb.org/extlink&oid=49170532&loc=d3e12355-112629

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

- Definition

The total amount of the contingent obligation under letters of credit outstanding as of the reporting date.

+ References

No definition available.

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
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 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(22))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 210
-Section S99
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-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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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- 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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Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

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

+ References

+ Details

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

- Definition

Description of the interest rate for the amounts borrowed under the credit facility, including the terms and the method for determining the interest rate (for example, fixed or variable, LIBOR plus a percentage, increasing rate, timing of interest rate resets, remarketing provisions).

+ References

+ 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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Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- 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

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-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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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Amount of stock repurchase plan authorized.

+ References

No definition available.

+ Details

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

- 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

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Balance Type:	debit
Period Type:	instant

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- Details

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Balance Type:
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- Details

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Balance Type:
Period Type:

- Details

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- Details

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Long-Term Debt - Additional Information (Detail) - USD ($)	1 Months Ended	3 Months Ended		12 Months Ended
	Dec. 31, 2017	Apr. 01, 2018	Apr. 02, 2017	Dec. 31, 2017	Mar. 27, 2018	Apr. 17, 2015
Debt Instrument [Line Items]
Borrowings during the period		$ 40,000,000	$ 60,000,000
September 6, 2016 Share Repurchase Program [Member]
Debt Instrument [Line Items]
Shares authorized to be repurchased		250,000,000
Principal payments on the Credit Facility		20,000,000
Amended and Restated Credit Agreement [Member]
Debt Instrument [Line Items]
Borrowings under credit facilities		$ 368,000,000
Fixed portion of outstanding debt percentage	70.00%
Participation fee		1.50%
Issuance fee		0.125%
Credit facility termination date		Mar. 27, 2023
Net leverage ratio		325.00%
Interest coverage ratio		175.00%
Former Credit Facility [Member]
Debt Instrument [Line Items]
Credit facility maximum borrowing capacity						$ 450,000,000
Borrowings under credit facilities	$ 348,000,000			$ 348,000,000
Credit facility termination date		Apr. 17, 2020
Borrowings during the period				153,000,000
Former Credit Facility [Member] \| September 6, 2016 Share Repurchase Program [Member]
Debt Instrument [Line Items]
Shares authorized to be repurchased	$ 250,000,000			250,000,000
Principal payments on the Credit Facility				$ 60,000,000
Former Credit Facility [Member] \| Swingline Loan Subfacility [Member]
Debt Instrument [Line Items]
Debt instrument face amount						15,000,000
Senior Lien [Member] \| Secured Debt [Member] \| Amended and Restated Credit Agreement [Member]
Debt Instrument [Line Items]
Loss on early extinguishment of debt		$ (300,000)
Letters of credit issued		$ 27,000,000
Line of credit interest rate terms		LIBOR plus 1.50% per annum. The interest rate margins are subject to adjustment pursuant to a pricing grid based on the Company’s total net leverage ratio, as set forth in the Amended and Restated Credit Agreement.
Senior Lien [Member] \| Secured Debt [Member] \| Amended and Restated Credit Agreement [Member] \| LIBOR [Member]
Debt Instrument [Line Items]
Interest rate spread on base rate		1.50%
Senior Lien [Member] \| Secured Debt [Member] \| Amended and Restated Credit Agreement [Member] \| Minimum [Member]
Debt Instrument [Line Items]
Credit facility unused commitment fee percentage		0.15%
Senior Lien [Member] \| Secured Debt [Member] \| Amended and Restated Credit Agreement [Member] \| Maximum [Member]
Debt Instrument [Line Items]
Credit facility unused commitment fee percentage		0.30%
Senior Lien [Member] \| Secured Debt [Member] \| Amended and Restated Credit Agreement [Member] \| Swingline Loan Subfacility [Member]
Debt Instrument [Line Items]
Debt instrument face amount		$ 15,000,000
Senior Lien [Member] \| Secured Debt [Member] \| $700.0 million Credit Facility [Member]
Debt Instrument [Line Items]
Debt instrument face amount		700,000,000
Senior Lien [Member] \| Secured Debt [Member] \| $700.0 million Credit Facility [Member] \| Amended and Restated Credit Agreement [Member]
Debt Instrument [Line Items]
Credit facility maximum borrowing capacity					$ 700,000,000
Capitalized debt issuance costs		$ 2,100,000
Interest expense term		5 years
Senior Lien [Member] \| Secured Debt [Member] \| Former Credit Facility [Member]
Debt Instrument [Line Items]
Credit facility maximum borrowing capacity						$ 450,000,000
Borrowings under credit facilities		$ 0
Line of credit interest rate terms		LIBOR plus 1.50% per annum, or a base rate plus 0.50% per annum. The interest rate margins were subject to adjustment pursuant to a pricing grid based on the Company’s total gross leverage ratio, as defined in the Former Credit Facility.
Credit facility unused commitment fee percentage		0.20%
Senior Lien [Member] \| Secured Debt [Member] \| Former Credit Facility [Member] \| LIBOR [Member]
Debt Instrument [Line Items]
Interest rate spread on base rate		1.50%
Senior Lien [Member] \| Secured Debt [Member] \| Former Credit Facility [Member] \| Alternate Base Rate [Member]
Debt Instrument [Line Items]
Interest rate spread on base rate		0.50%
Senior Lien [Member] \| Secured Debt [Member] \| Former Credit Facility [Member] \| Amended and Restated Credit Agreement [Member]
Debt Instrument [Line Items]
Capitalized debt issuance costs		$ 700,000