Debt - Additional Information (Detail) - USD ($)		12 Months Ended
Feb. 22, 2017	Dec. 31, 2017
Debt Instrument [Line Items]
Effective interest rate		3.50%
Percentage of outstanding debt priced		50.40%
2017 Credit Agreement [Member]
Debt Instrument [Line Items]
Credit agreement commencement date	Feb. 22, 2017
Credit agreement period	5 years
Line of credit facility, collateral amount	$ 165,000,000
Line of credit facility, interest rate description		Borrowings under the 2017 Credit Agreement bear interest at LIBOR for specified interest periods, at the Alternate Base Rate (as defined in the 2017 Credit Agreement) or, in the case of swingline loans only, at the REVLIBOR30 Rate (as defined in the 2017 Credit Agreement) plus, in each case, a margin determined based on the type of the borrowing and the Company’s average quarterly revolving availability, ranging from 0.25% to 2.50%. In addition, ECO is required to pay the lenders a commitment fee on the unutilized portion of the revolving and FILO commitments under the 2017 Credit Agreement at a rate per annum equal to 0.25%. Letters of credit issued pursuant to the 2017 Credit Agreement incur fees based on the applicable margin rate for revolving LIBOR-based Loans, plus 0.125%. Interest on the Notes is payable semi-annually at a rate per annum equal to 3.75%. Applicable deferred financing fees associated with the transaction will be amortized over the life of the 2017 Credit Agreement.
2017 Credit Agreement [Member] \| LIBOR Loans [Member]
Debt Instrument [Line Items]
Basis spread on variable rate	0.125%
2017 Credit Agreement [Member] \| Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Maximum borrowing capacity	$ 1,000,000,000
Fee on unutilized portion of commitments	0.25%
Credit facility termination date	Feb. 22, 2022
2017 Credit Agreement [Member] \| First In Last Out Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Maximum borrowing capacity	$ 100,000,000
Fee on unutilized portion of commitments	0.25%
Credit facility termination date	Feb. 22, 2022
2017 Credit Agreement [Member] \| Term Loan Facility [Member]
Debt Instrument [Line Items]
Debt instrument, maturity date	Feb. 22, 2022
Maximum borrowing capacity	$ 77,600,000
Debt instrument, periodic payment	$ 506,000
Debt instrument, frequency of periodic payment		monthly
2017 Credit Agreement [Member] \| Maximum [Member]
Debt Instrument [Line Items]
Debt-to-EBITDA ratio	3.50%
Letters of credit issued amount	$ 50,000,000
2017 Credit Agreement [Member] \| Maximum [Member] \| Revolving Credit Facility [Member] \| REVLIBOR30 Rate [Member]
Debt Instrument [Line Items]
Line of credit facility loan rates	2.50%
2017 Credit Agreement [Member] \| Minimum [Member]
Debt Instrument [Line Items]
Debt-to-EBITDA ratio	3.00%
2017 Credit Agreement [Member] \| Minimum [Member] \| Revolving Credit Facility [Member] \| REVLIBOR30 Rate [Member]
Debt Instrument [Line Items]
Line of credit facility loan rates	0.25%
3.75% Senior Secured Notes [Member]
Debt Instrument [Line Items]
Debt instrument, interest rate, stated percentage	3.75%
Debt instrument, maturity date	Jan. 15, 2021
2013 Note Purchase Agreement [Member]
Debt Instrument [Line Items]
Debt instrument, maturity date	Jan. 15, 2021

Debt instrument outstanding percentage excluding capital leases and transaction costs.

No definition available.

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Namespace Prefix:	esnd_
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Balance Type:	na
Period Type:	instant

- Definition

Debt to earnings before interest, tax, depreciation and amortization.

+ References

No definition available.

+ Details

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Namespace Prefix:	esnd_
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Balance Type:	na
Period Type:	duration

- Definition

Issuance of letter of credit.

+ References

No definition available.

+ Details

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Namespace Prefix:	esnd_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Line of credit facility collateral amount

+ References

No definition available.

+ Details

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Namespace Prefix:	esnd_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
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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Balance Type:	na
Period Type:	duration

- Definition

Description of the frequency of periodic payments (monthly, quarterly, annual).

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 470
-Section 50
-Paragraph 3
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=75038535&loc=d3e64711-112823

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

+ Details

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Period Type:	duration

- 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=64930785&loc=d3e28551-108399

+ Details

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Balance Type:	na
Period Type:	instant

- Definition

Contractual interest rate for funds borrowed, under the debt agreement.

+ References

+ Details

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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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Period Type:	duration

- Definition

Date when the debt instrument is scheduled to be fully repaid, 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

Amount of the required periodic payments including both interest and principal payments.

+ 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 942
-SubTopic 470
-Section 50
-Paragraph 3
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=75038535&loc=d3e64711-112823

+ Details

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

- 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

Period remaining on line of credit facility before it terminates, 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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Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Date the credit facility first became available, in CCYY-MM-DD format.

+ References

+ Details

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Data Type:	xbrli:dateItemType
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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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Period Type:	duration

- Definition

The effective interest rate during the reporting period.

+ References

+ Details

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Data Type:	num:percentItemType
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

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
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Period Type:	duration

- 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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