This represents the liability for early payment of pension plan benefit in a single lump sum payment.

No definition available.

Name:	jwa_DefinedBenefitPensionPlanLiabilityForEarlyPaymentOfPensionPlanBenefitInSingleLumpSum
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Data Type:	xbrli:monetaryItemType
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Period Type:	instant

- Definition

The amount of payments for early lump sum payment made for which eligible participants are entitled under a pension plan.

+ References

No definition available.

+ Details

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- Definition

Refers to eligible participants who made the election to receive the lump sum amount which was paid from Pension Plan assets.

+ References

No definition available.

+ Details

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- Definition

The amount of pension benefit costs recognized during the period for one-time non-cash charge for settlement of a portion of a defined benefit pension plan.

+ References

No definition available.

+ Details

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

- Definition

Amount of gain (loss) recognized in net periodic benefit (cost) credit of defined benefit plan.

+ References

+ Details

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

- Definition

Amount of prior service cost (credit) recognized in net periodic benefit cost (credit) of defined benefit plan.

+ References

+ Details

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

- Definition

Weighted average rate for present value of future retirement benefits cash flows, used to determine net periodic benefit cost of defined benefit plan.

+ References

+ Details

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Data Type:	num:percentItemType
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Period Type:	duration

- Definition

Weighted average rate of return on plan assets, reflecting average rate of earnings expected on existing plan assets and expected contributions, used to determine net periodic benefit cost of defined benefit plan.

+ References

+ Details

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Data Type:	num:percentItemType
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Period Type:	duration

- Definition

Weighted average rate of compensation increase used to determine net periodic benefit cost of defined benefit plan. Plan includes, but is not limited to, pay-related defined benefit plan.

+ References

+ Details

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- Definition

Amount of expected return (loss) recognized in net periodic benefit (cost) credit, calculated based on expected long-term rate of return and market-related value of plan assets of defined benefit plan.

+ References

+ Details

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

- Definition

Amount of cost recognized for passage of time related to defined benefit plan.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (h)(2)
-URI http://asc.fasb.org/extlink&oid=82843861&loc=d3e1928-114920

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (a)(2)
-URI http://asc.fasb.org/extlink&oid=82843861&loc=d3e1928-114920

+ Details

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

- Definition

Amount of net periodic benefit cost (credit) for defined benefit plan.

+ References

+ Details

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

- References

No definition available.

+ Details

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- References

No definition available.

+ Details

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- Definition

Amount of accumulated benefit obligation for defined benefit pension plan with accumulated benefit obligation in excess of plan assets.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 50
-Paragraph 3
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=82843861&loc=d3e2417-114920

+ Details

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Data Type:	xbrli:monetaryItemType
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Period Type:	instant

- Definition

Fair value of plan assets for defined benefit pension plan with accumulated benefit obligation in excess of plan assets.

+ References

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Amount of projected benefit obligation for defined benefit pension plan with accumulated benefit obligation in excess of plan assets.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 55
-Paragraph 17
-URI http://asc.fasb.org/extlink&oid=77993564&loc=d3e4179-114921

+ Details

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Data Type:	xbrli:monetaryItemType
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Period Type:	instant

- Definition

Amount of gain (loss) recognized in net periodic benefit (cost) credit from event reducing expected years of future service of present employees or eliminating accrual of defined benefits for some or all future services of present employees.

+ References

+ Details

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

- Definition

Amount of cost for actuarial present value of benefits attributed to service rendered by employee for defined benefit plan.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (h)(1)
-URI http://asc.fasb.org/extlink&oid=82843861&loc=d3e1928-114920

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (a)(1)
-URI http://asc.fasb.org/extlink&oid=82843861&loc=d3e1928-114920

+ Details

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

- References

No definition available.

+ Details

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Data Type:	xbrli:stringItemType
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- Details

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- Details

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Balance Type:
Period Type:

- Details

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Retirement Plans, Components of Net Pension Expense (Income) and Weighted-Average Assumptions (Details) $ in Thousands		1 Months Ended	12 Months Ended
	Aug. 29, 2016 USD ($) Participant	Oct. 31, 2016 USD ($)	Apr. 30, 2018 USD ($)	Apr. 30, 2017 USD ($)	Apr. 30, 2016 USD ($)
Weighted-average assumptions [Abstract]
Net actuarial loss related to early lump sum payment of pension plan benefit			$ 0	$ 8,842	$ 0
Retirement plans with accumulated benefit obligations in excess of plan assets [Abstract]
Projected benefit obligation for plans with accumulated benefit obligations in excess of plan assets			820,400	800,100
Accumulated benefit obligation for plans with accumulated benefit obligations in excess of plan assets			787,600	753,300
Fair value of plan assets for plans with accumulated benefit obligations in excess of plan assets			624,400	579,700
U.S. [Member]
Defined benefit plans, net pension expense (income) [Abstract]
Service Cost			0	0	0
Interest Cost			11,666	12,398	13,612
Expected Return on Plan Assets			(13,154)	(14,053)	(14,756)
Net Amortization of Prior Service Cost			(154)	(154)	(154)
Recognized Net Actuarial Loss			2,289	2,622	2,240
Curtailment/Settlement Loss			0	8,842	1,857
Net Pension Expense (Income)			$ 647	$ 9,655	$ 2,799
Weighted-average assumptions [Abstract]
Discount Rate			4.10%	4.00%	4.20%
Rate of Compensation Increase
Expected Return on Plan Assets			6.80%	6.80%	6.80%
Number of eligible participants \| Participant	780
Total liability for early payment of pension plan benefit in a single lump sum payment	$ 28,300
Lump sum payment for early payment of pension plan benefit		$ 28,300
Net actuarial loss related to early lump sum payment of pension plan benefit				$ 8,800
U.S. [Member] \| Supplemental Executive Retirement Plan [Member]
Defined benefit plans, net pension expense (income) [Abstract]
Curtailment/Settlement Loss					$ 1,900
Non-U.S. [Member]
Defined benefit plans, net pension expense (income) [Abstract]
Service Cost			$ 960	967	1,455
Interest Cost			13,876	14,449	16,446
Expected Return on Plan Assets			(26,385)	(21,173)	(25,088)
Net Amortization of Prior Service Cost			57	54	55
Recognized Net Actuarial Loss			3,832	2,553	2,475
Curtailment/Settlement Loss			19	0	0
Net Pension Expense (Income)			$ (7,641)	$ (3,150)	$ (4,657)
Weighted-average assumptions [Abstract]
Discount Rate			2.60%	3.50%	3.50%
Rate of Compensation Increase			3.00%	3.00%	3.00%
Expected Return on Plan Assets			6.50%	6.70%	6.70%