Period which an employee's right to exercise an award is no longer contingent on satisfaction of either a service condition, market condition or a performance condition, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (a)(1)
-URI http://asc.fasb.org/extlink&oid=96867065&loc=d3e5070-113901

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- Definition

The number of grants made during the period on other than stock (or unit) option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, performance target plan).

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)(2)(iii)(1)
-URI http://asc.fasb.org/extlink&oid=96867065&loc=d3e5070-113901

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Period Type:	duration

- Definition

Gross number of share options (or share units) granted during the period.

+ References

No definition available.

+ Details

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- Definition

Weighted average per share amount at which grantees can acquire shares of common stock by exercise of options.

+ References

No definition available.

+ Details

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

- Definition

Percentage of vesting of share-based compensation awards.

+ References

+ Details

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- Definition

Period from grant date that an equity-based award expires, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (a)(2)
-URI http://asc.fasb.org/extlink&oid=96867065&loc=d3e5070-113901

+ Details

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

- Definition

Amount of stock repurchase plan authorized.

+ References

No definition available.

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
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- Definition

Detail information of subsequent event by type. User is expected to use existing line items from elsewhere in the taxonomy as the primary line items for this disclosure, which is further associated with dimension and member elements pertaining to a subsequent event.

+ References

No definition available.

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Namespace Prefix:
Data Type:	na
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- Details

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- Details

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Subsequent Events (Narrative) (Details) - USD ($)				12 Months Ended
Subsequent Events (Narrative) (Details) - USD ($)	May 07, 2018	Aug. 01, 2017	May 08, 2017	Mar. 31, 2018	Mar. 31, 2017	Mar. 31, 2016	May 10, 2018
Subsequent Event [Line Items]
Options, grant date fair value (in USD per share)				$ 56.11	$ 55.86	$ 42.13
Options granted (in shares)				182,800	264,300	208,200
Performance Units
Subsequent Event [Line Items]
Common stock units granted in period (in shares)			35,593
Restricted Stock Units (RSUs)
Subsequent Event [Line Items]
Common stock units granted in period (in shares)		2,564	54,773	105,800	68,400	266,100
Options granted (in shares)		1
Award vesting period				3 years
Stock Options
Subsequent Event [Line Items]
Options granted (in shares)		1	182,823
Subsequent Event
Subsequent Event [Line Items]
Shares authorized for repurchase							$ 50,000,000.0
Options, grant date fair value (in USD per share)	$ 29.46
Subsequent Event \| Performance Units
Subsequent Event [Line Items]
Common stock units granted in period (in shares)	103,406
Award vesting period	3 years
Subsequent Event \| Restricted Stock Units (RSUs)
Subsequent Event [Line Items]
Vesting rights (as percent)	33.30%
Common stock units granted in period (in shares)	100,399
Award vesting period	3 years
Subsequent Event \| Stock Options
Subsequent Event [Line Items]
Expiration period	10 years
Vesting rights (as percent)	33.30%
Options granted (in shares)	294,484
Award vesting period	3 years