Closing price per share of company's common stock at balance sheet date

No definition available.

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- Definition

Share Based Compensation Arrangement By Share Based Payment Award Accelerated Compensation Cost

+ References

No definition available.

+ Details

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Period Type:	duration

- Definition

Share-based Compensation Arrangement by Share-based Payment Award Assumed Awards At Acquisition Date Estimated Fair Value

+ References

No definition available.

+ Details

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Period Type:	instant

- Definition

The intrinsic value of share-based payment equity instruments, excluding stock options, outstanding during the reporting period as calculated by applying the disclosed pricing methodology.

+ References

No definition available.

+ Details

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- Definition

The intrinsic value of share-based payment equity instruments, excluding stock options, that vested during the reporting period as calculated by applying the disclosed pricing methodology.

+ References

No definition available.

+ Details

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- Definition

Represents the expense recognized during the period arising from equity-based compensation arrangements (for example, shares of stock, unit, stock options or other equity instruments) with employees, directors and certain consultants qualifying for treatment as employees.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 718

-SubTopic 10

-Section 50

-Paragraph 1

-Subparagraph (b)

-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5047-113901

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 718

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (h)(1)(i)

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

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 123R

-Paragraph A240

-Subparagraph g(1)

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 4: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 718

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SAB TOPIC 14.F)

-URI http://asc.fasb.org/extlink&oid=6793087&loc=d3e301413-122809

Reference 5: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Staff Accounting Bulletin (SAB)

-Number Topic 14

-Section F

Reference 6: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 123R

-Paragraph 64

-Subparagraph b

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

+ Details

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

- Definition

This element represents the acquisition-date fair value of any tangible or intangible assets, including a business or subsidiary of the acquirer, but excluding cash, transferred by the entity to the former owners of the acquire.

+ References

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 141R

-Paragraph 68

-Subparagraph f(2)

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 805

-SubTopic 30

-Section 50

-Paragraph 1

-Subparagraph (b)(2)

-URI http://asc.fasb.org/extlink&oid=6911361&loc=d3e6927-128479

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Period Type:	instant

- Definition

As of the balance sheet date, the aggregate unrecognized cost of equity-based awards made to employees under equity-based compensation awards that have yet to vest.

+ References

+ Details

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Balance Type:	debit
Period Type:	instant

- Definition

The weighted average period over which unrecognized compensation is expected to be recognized for equity-based compensation plans, using a decimal to express in number of years.

+ References

+ Details

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- Definition

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).

+ References

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 123R

-Paragraph A240

-Subparagraph b(2)(c)

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 123R

-Paragraph A240

-Subparagraph c(1)

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 3: 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=6415400&loc=d3e5070-113901

+ Details

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- Definition

The total dollar difference between fair values of the underlying shares reserved for issuance and exercise prices of vested portions of options outstanding and currently exercisable under the option plan as of the balance sheet date.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 718

-SubTopic 10

-Section 50

-Paragraph 2

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

+ Details

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

- Definition

The total accumulated difference between fair values of underlying shares on dates of exercise and exercise price on options which were exercised (or share units converted) into shares during the reporting period under the plan.

+ References

+ Details

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

- Definition

The weighted average grant-date fair value of options granted during the reporting period as calculated by applying the disclosed option pricing methodology.

+ References

+ Details

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- Definition

The total dollar difference between fair values of the underlying shares reserved for issuance and exercise prices pertaining to options outstanding under the plan as of the balance sheet date.

+ References

+ Details

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- Definition

The number of exercisable share options (fully vested and expected to vest) that may be converted as of the balance sheet date.

+ References

+ Details

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Period Type:	instant

- Definition

As of the balance sheet date, the weighted-average exercise price (at which grantees can acquire the shares reserved for issuance) for exercisable stock options that are fully vested or expected to vest.

+ References

+ Details

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Equity Incentive Plans, Share-based Payment Award (Details) (USD $) Share data in Thousands, except Per Share data, unless otherwise specified	3 Months Ended		6 Months Ended		3 Months Ended			3 Months Ended			6 Months Ended		3 Months Ended	6 Months Ended		3 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012 SMSC Acquisition [Member]	Aug. 02, 2012 SMSC Acquisition [Member]	Aug. 02, 2012 Pre Acquisition Estimated Fair Value Of Share Based Awards Vested Service [Member] SMSC Acquisition [Member]	Sep. 30, 2012 Post Acquisition Estimated Fair Value Of Share Based Awards [Member] Scenario, Forecast [Member] SMSC Acquisition [Member]	Sep. 30, 2012 Restricted Stock Units (RSUs) [Member]	Sep. 30, 2011 Restricted Stock Units (RSUs) [Member]	Sep. 30, 2012 Restricted Stock Units (RSUs) [Member]	Sep. 30, 2011 Restricted Stock Units (RSUs) [Member]	Sep. 30, 2012 Stock Option [Member]	Sep. 30, 2012 Stock Option [Member]	Sep. 30, 2011 Stock Option [Member]	Sep. 30, 2012 Stock Appreciation Rights (SARs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation expense related to unvested share based payment awards	$ 86,800,000		$ 86,800,000
Weighted average period of unearned share-based compensation expected to be recognized (in years)			1.88								1.97
Share based compensation expense due to accelerated vesting of outstanding equity awards					7,800,000
Estimated fair value of assumed awards at the acquisition date						28,200,000
Consideration transferred as part of the acquisition							6,900,000
Closing price of company's common stock related to calculation of aggregate intrinsic value of restricted stock units (in dollars per share)			$ 32.74
Total Intrinsic Value Of Restricted Stock Units Vested									12,500,000		22,300,000
Total Intrinsic Value Of Restricted Stock Units Outstanding									195,100,000		195,100,000
Weighted average fair value of restricted stock units awarded in period (amount per share)									$ 30.30	$ 31.61	$ 30.61	$ 32.27
Allocated Share-based Compensation Expense	17,134,000	8,258,000	25,798,000	16,114,000				21,300,000
Total intrinsic value of stock options exercised													4,400,000	6,900,000
Aggregate intrinsic value of stock options outstanding													23,800,000	23,800,000		4,900,000
Aggregate intrinsic value of stock options exercisable													$ 21,700,000	$ 21,700,000
Number of stock awards exercisable (in shares)													2,849,127	2,849,127	4,566,785	1,592
Weighted average exercise price (in dollars per share)													$ 25.23	$ 25.23	$ 25.17	$ 26.91
Weighted average fair value of stock awards issued (in dollars per share)													$ 13.10			$ 14.68