Executive Stock Plans And Stock-Based Compensation (Summary Of RSU, Restricted Stock, And PSA Activity) (Details) (USD $) In Thousands, except Per Share data, unless otherwise specified	12 Months Ended
Mar. 31, 2012	Mar. 31, 2011	Mar. 31, 2010	Mar. 31, 2009
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted, Weighted- Average Grant Date Fair Value	$ 7.46	$ 8.35	$ 7.85
Restricted Stock Units (RSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted, Shares	84,290	63,992	73,589
Vested, Shares	(39,827)	(24,940)	(14,955)
Forfeited, Shares
Unvested at end of year, Shares	291,279	246,816	207,764	149,130
Granted, Weighted- Average Grant Date Fair Value	$ 38.28	$ 41.40	$ 35.93
Vested, Weighted- Average Grant Date Fair Value	$ 35.94	$ 46.35	$ 47.21
Forfeited, Weighted- Average Grant Date Fair Value
Unvested at end of year, Weighted- Average Grant Date Fair Value	$ 43.72	$ 44.07	$ 32.50	$ 49.84
Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted, Shares			17,550
Vested, Shares	(10,350)	(7,000)	(7,700)
Forfeited, Shares
Unvested at end of year, Shares	67,400	77,750	84,750	74,900
Granted, Weighted- Average Grant Date Fair Value			$ 39.76
Vested, Weighted- Average Grant Date Fair Value	$ 37.52	$ 41.96	$ 40.41
Forfeited, Weighted- Average Grant Date Fair Value
Unvested at end of year, Weighted- Average Grant Date Fair Value	$ 41.91	$ 40.77	$ 40.87	$ 41.08
Performance Share Awards [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted, Shares	57,383	38,400	63,450
Vested, Shares	(44,352)
Forfeited, Shares	(1,984)		(897)
Unvested at end of year, Shares	142,466	131,419	93,019	30,466
Granted, Weighted- Average Grant Date Fair Value	$ 35.56	$ 33.95	$ 29.67
Vested, Weighted- Average Grant Date Fair Value	$ 45.96
Forfeited, Weighted- Average Grant Date Fair Value	$ 33.30		$ 45.96
Unvested at end of year, Weighted- Average Grant Date Fair Value	$ 31.45	$ 34.59	$ 34.85	$ 45.96

The weighted average fair value at grant date for nonvested equity-based awards issued 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).

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The number of non-vested equity-based payment instruments, excluding stock (or unit) options, that validly exist and are outstanding as of the balance sheet date.

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- Definition

The weighted average fair value of nonvested awards on equity-based plans excluding option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, revenue or profit achievement stock award plan) for which the employer is contingently obligated to issue equity instruments or transfer assets to an employee who has not yet satisfied service or performance criteria necessary to gain title to proceeds from the sale of the award or underlying shares or units.

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- Definition

The weighted average fair value as of grant date pertaining to an equity-based award plan other than a stock (or unit) option plan for which the grantee gained the right during the reporting period, by satisfying service and performance requirements, to receive or retain shares or units, other instruments, or cash in accordance with the terms of the arrangement.

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