Special Charges (Details) (Unusual or Infrequent Item [Member], USD $) In Millions, unless otherwise specified	3 Months Ended
	Jun. 30, 2013
Unusual or Infrequent Item [Line Items]
Other Nonrecurring Expense	$ 1.7
Roving Networks Acquisition [Member]
Unusual or Infrequent Item [Line Items]
Business Combination, Contingent Consideration Arrangements, Change in Amount of Contingent Consideration, Liability	1.4
SMSC Acquisition [Member]
Unusual or Infrequent Item [Line Items]
Severance-related, office closing costs and other restructuring costs	$ 0.3