Stock-Based Compensation (Summary of Stock Option Activity) (Details) (Stock Option [Member], USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended
Jun. 30, 2014
Stock Option [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Outstanding at March 31, 2014	5,104
Granted	921
Exercised	(275)
Forfeited	(18)
Outstanding at June 30, 2014	5,732
Vested or expected to vest at June 30, 2014, Number Of Stock Options	5,700
Exercisable at June 30, 2014, Number Of Stock Options	3,505
Outstanding at March 31, 2014, Weighted-Average Exercise Price Per Share	$ 69.91
Granted, Weighted-Average Exercise Price Per Share	$ 104.64
Exercised, Weighted-Average Exercise Price Per Share	$ 48.33
Forfeited, Weighted-Average Exercise Price Per Share	$ 91.06
Outstanding at June 30, 2014, Weighted-Average Exercise Price Per Share	$ 76.46
Vested or expected to vest at June 30, 2014, Weighted-Average Exercise Price Per Share	$ 76.32
Exercisable at June 30, 2014, Weighted-Average Exercise Price Per Share	$ 62.84

The number of shares into which fully or partially vested stock options outstanding as of the balance sheet date can be currently converted under the option plan.

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)(1)(iii)

-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

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The weighted-average price as of the balance sheet date at which grantees can acquire the shares reserved for issuance on vested portions of options outstanding and currently exercisable under the stock option plan.

+ References

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- Definition

The number of shares under options that were cancelled during the reporting period as a result of occurrence of a terminating event specified in contractual agreements pertaining to the stock option plan.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 718

-SubTopic 10

-Section 50

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-Subparagraph (c)(1)(iv)(3)

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

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- Definition

Number of options outstanding, including both vested and non-vested options.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

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Weighted average price at which grantees can acquire the shares reserved for issuance under the stock option plan.

+ References

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As of the balance sheet date, the number of shares into which fully vested and expected to vest stock options outstanding can be converted under the option plan.

+ References

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As of the balance sheet date, the weighted-average exercise price for outstanding stock options that are fully vested or expected to vest.

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Weighted average price at which option holders acquired shares when converting their stock options into shares.

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Weighted average price at which grantees could have acquired the underlying shares with respect to stock options that were terminated.

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

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Number of share options (or share units) exercised during the current period.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 04

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