Business Acquisitions (Details) (USD $)	3 Months Ended
	Jun. 30, 2012	Apr. 18, 2012
Business Acquisition [Line Items]
Contingent consideration	14,700,000
Roving Networks Acquisition [Member]
Business Acquisition [Line Items]
Business Acquisition, Cost of Acquired Entity, Purchase Price		20,600,000
Contingent consideration		14,700,000
Business Acquisition, Purchase Price Allocation, Amortizable Intangible Assets		22,800,000
Business Acquisition, Purchase Price Allocation, Goodwill Amount		8,700,000
Finite-Lived Intangible Assets, Useful Life, Minimum	4
Finite-Lived Intangible Assets, Useful Life, Maximum	10
Developed Technology Rights [Member] | Roving Networks Acquisition [Member]
Business Acquisition [Line Items]
Business Acquisition, Purchase Price Allocation, Amortizable Intangible Assets		10,600,000
Customer Relationships [Member] | Roving Networks Acquisition [Member]
Business Acquisition [Line Items]
Business Acquisition, Purchase Price Allocation, Amortizable Intangible Assets		10,600,000
Order or Production Backlog [Member] | Roving Networks Acquisition [Member]
Business Acquisition [Line Items]
Business Acquisition, Purchase Price Allocation, Amortizable Intangible Assets		300,000
In Process Research And Development Member | Roving Networks Acquisition [Member]
Business Acquisition [Line Items]
Business Acquisition, Purchase Price Allocation, Amortizable Intangible Assets		$ 1,300,000