Debt instrument maturity period.

No definition available.

Name:	exp_DebtInstrumentMaturityPeriod
Namespace Prefix:	exp_
Data Type:	xbrli:gYearMonthItemType
Balance Type:	na
Period Type:	duration

- Definition

Interest coverage ratio minimum.

+ References

No definition available.

+ Details

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Namespace Prefix:	exp_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Letter of credit maximum capacity.

+ References

No definition available.

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
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_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount, before unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but is not limited to, notes payable, bonds payable, commercial loans, mortgage loans, convertible debt, subordinated debt and other types of debt.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 20
-Section 50
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+ Details

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

- 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/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 20
-Section 50
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+ Details

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

- Definition

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

+ References

+ Details

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

- Definition

Date when the debt instrument is scheduled to be fully repaid, in CCYY-MM-DD format.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
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-URI http://asc.fasb.org/extlink&oid=117815213&loc=d3e19207-110258

+ Details

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

- Definition

Percentage price of original principal amount of debt at which debt can be redeemed by the issuer.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
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+ Details

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

- Definition

Amount of unused borrowing capacity under the long-term financing arrangement that is available to the entity as of the balance sheet date.

+ References

+ Details

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

- Definition

Weighted average interest rate of debt outstanding.

+ References

No definition available.

+ Details

Name:	us-gaap_DebtWeightedAverageInterestRate
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

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

+ References

No definition available.

+ Details

Name:	us-gaap_LettersOfCreditOutstandingAmount
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

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

- Definition

Fair value of the amount outstanding under the credit facility.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
-Section 50
-Paragraph 10
-URI http://asc.fasb.org/extlink&oid=121572278&loc=d3e13433-108611

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

- 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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Namespace Prefix:	us-gaap_
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 borrowing capacity currently available under the credit facility (current borrowing capacity less the amount of borrowings outstanding).

+ References

+ Details

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

- Definition

Ratio of Tier 1 risk-based capital to total leverage exposure as defined by regulatory framework.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 505
-Section 50
-Paragraph 1
-Subparagraph (c)(1)
-URI http://asc.fasb.org/extlink&oid=117337116&loc=SL5958568-112826

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:pureItemType
Balance Type:	na
Period Type:	instant

- Details

Name:	srt_RangeAxis=srt_MinimumMember
Namespace Prefix:
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Balance Type:
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- Details

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Balance Type:
Period Type:

- Details

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Period Type:

- Details

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Balance Type:
Period Type:

- Details

Name:	us-gaap_VariableRateAxis=exp_NewYorkFederalReserveBankMember
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Data Type:	na
Balance Type:
Period Type:

- Details

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Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_LongtermDebtTypeAxis=exp_TermLoanMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_LongtermDebtTypeAxis=exp_TermLoanAgreementMember
Namespace Prefix:
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Balance Type:
Period Type:

- Details

Name:	us-gaap_LongtermDebtTypeAxis=exp_FourPointFiveZeroZeroPercentageSeniorUnsecuredNotesDueTwoThousandTwentySixMember
Namespace Prefix:
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- Details

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Namespace Prefix:
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Balance Type:
Period Type:

- Details

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Namespace Prefix:
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Balance Type:
Period Type:

- Details

Name:	us-gaap_LongtermDebtTypeAxis=exp_SwinglineLoanMember
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Balance Type:
Period Type:

- Details

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Period Type:

- Details

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Indebtedness - Additional Information (Detail)				12 Months Ended
Indebtedness - Additional Information (Detail)	Dec. 20, 2019	Aug. 02, 2016 USD ($)	Oct. 31, 2014	Mar. 31, 2021 USD ($)	Mar. 31, 2019	Mar. 31, 2020 USD ($)	Dec. 31, 2019 USD ($)
Debt Instrument [Line Items]
Weighted-average interest rate				2.80%	3.40%	3.60%
Interest rate of debt instrument						2.80%
Supplementary leverage ratio			3.50
Interest coverage ratio			250.00%
Borrowings outstanding under Credit Facility						$ 560,000,000	$ 0
Outstanding borrowings							745,700,000
Letter of Credit Facility				$ 40,000,000.0
Outstanding letters of credit , amount				4,300,000			$ 4,300,000
Debt instrument, principal amount				$ 1,015,000,000		$ 1,575,000,000
Minimum [Member] \| Maturity Period 2021 [Member]
Debt Instrument [Line Items]
Unused line of credit commitment fee based on leverage ratio			0.15%
Maximum [Member] \| Maturity Period 2021 [Member]
Debt Instrument [Line Items]
Unused line of credit commitment fee based on leverage ratio			0.30%
London Interbank Offered Rate (LIBOR) [Member] \| Minimum [Member] \| Maturity Period 2021 [Member]
Debt Instrument [Line Items]
Variable margin			1.25%
London Interbank Offered Rate (LIBOR) [Member] \| Maximum [Member] \| Maturity Period 2021 [Member]
Debt Instrument [Line Items]
Variable margin			2.00%
NYFRB [Member]
Debt Instrument [Line Items]
Variable margin			1.00%
NYFRB [Member] \| Minimum [Member]
Debt Instrument [Line Items]
Variable margin			1.25%
NYFRB [Member] \| Minimum [Member] \| Maturity Period 2022 [Member]
Debt Instrument [Line Items]
Variable margin			0.25%
NYFRB [Member] \| Maximum [Member]
Debt Instrument [Line Items]
Variable margin			2.00%
NYFRB [Member] \| Maximum [Member] \| Maturity Period 2022 [Member]
Debt Instrument [Line Items]
Variable margin			1.00%
Term Loan [Member]
Debt Instrument [Line Items]
Weighted-average interest rate				2.50%		2.80%
Interest rate of debt instrument				1.40%		2.80%
Debt instrument, principal amount				$ 665,000,000		$ 665,000,000
Term Loan Agreement [Member]
Debt Instrument [Line Items]
Credit facility, interest rate description				Borrowings under the Term Loan Agreement bear interest, at our option, at a variable rate equal to either (i) the Alternate Base Rate (as defined in the Term Loan Agreement and consistent with the Revolving Credit Facility), plus an agreed spread (ranging from 25 to 100 basis points), or (ii) the Adjusted LIBO Rate (as defined in the Term Loan Agreement), plus an agreed spread (ranging from 125 to 200 basis points), which is established quarterly based on the Company's then Leverage Ratio (as defined in the Term Loan Agreement and consistent with the Revolving Credit Facility). The Company must also maintain a Leverage Ratio and Interest Coverage Ratio consistent with the Revolving Credit Facility.
Term loan facility, unused borrowing capacity, Amount				$ 665,000.0
Term loan Maturity Date				Aug. 02, 2023
Term Loan Agreement [Member] \| London Interbank Offered Rate (LIBOR) [Member] \| Minimum [Member]
Debt Instrument [Line Items]
Variable margin	0.25%
Term Loan Agreement [Member] \| London Interbank Offered Rate (LIBOR) [Member] \| Maximum [Member]
Debt Instrument [Line Items]
Variable margin	1.00%
4.500% Senior Unsecured Notes Due 2026 [Member]
Debt Instrument [Line Items]
Debt instrument, principal amount		$ 350,000,000.0		$ 350,000,000		350,000,000
Debt instrument, interest rate		4.50%		4.50%
Debt instrument, maturity period		2026-08
4.500% Senior Unsecured Notes Due 2026 [Member] \| On or After August 1, 2019 and Prior to August 1, 2021 [Member]
Debt Instrument [Line Items]
Redemption price, percentage		100.00%
Revolving Credit Facility
Debt Instrument [Line Items]
Line of Credit Facility, Fair Value of Amount Outstanding				$ 0
Credit Facility, principal balance						750,000,000.0
Credit Facility, termination date					Aug. 02, 2023
Credit facility, interest rate description				At the Company’s option, principal amounts outstanding under the Revolving Credit Facility bear interest at a variable rate equal to either (i) the Adjusted LIBO Rate (as defined in the Revolving Credit Facility) plus an agreed spread (ranging from 125 to 200 basis points), which is established quarterly based on the Company's then Leverage Ratio; or (ii) an Alternate Base Rate (as defined in the Revolving Credit Facility), which is the highest of (a) the Prime Rate (as defined in the Revolving Credit Facility), (b) the New York Federal Reserve Bank (NYFRB) (as defined in the Revolving Credit Facility) plus ½ of 1%, and (c) the Adjusted LIBO Rate for a one-month interest period on such day, plus 1.0%, in each case plus an agreed upon spread (ranging from 25 to 100 basis points), which is established quarterly based on the Company's then Leverage Ratio.
Revolving Credit Facility \| Swingline Loan [Member]
Debt Instrument [Line Items]
Credit Facility, principal balance						$ 25,000,000.0
Line of Credit [Member] \| NYFRB [Member]
Debt Instrument [Line Items]
Variable margin			0.50%
Letter of Credit [Member]
Debt Instrument [Line Items]
Unused line of credit commitment fee based on leverage ratio				0.125%