Business Combinations Business Combinations Intangible Assets Acquired (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Jun. 30, 2012	May 01, 2012
Acquired Finite-Lived Intangible Assets [Line Items]
Amortizable Intangible Assets		$ 24,000
Weighted Average Useful Life	8 years
Total Identified Intangible Assets		43,400
In Process Research and Development [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Intangible Assets Not Amortizable		19,400
Core Developed Technology [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Amortizable Intangible Assets		15,100
Weighted Average Useful Life	7 years
Customer Contracts And Relationships [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Amortizable Intangible Assets		$ 8,900
Weighted Average Useful Life	11 years