Acquisitions Summary of Fair Value of Assets Acquired and Liabilities Assumed by Major Class (Details) (USD $) In Millions, unless otherwise specified	Jun. 07, 2012
Business Acquisition [Line Items]
Business Acquisition, Purchase Price Allocation, Goodwill, Expected Tax Deductible Amount	$ 0
Business Acquisition, Purchase Price Allocation, Assets Acquired (Liabilities Assumed), Net	76.0
Vela Systems [Member]
Business Acquisition [Line Items]
Business Acquisition, Purchase Price Allocation, Goodwill Amount	57.6	[1]
Business Acquisition, Purchase Price Allocation, Current Liabilities, Deferred Revenue	(2.0)
Business Acquisition, Purchase Price Allocation, Deferred Taxes Asset (Liability), Net, Noncurrent	3.9
Business Acquisition, Purchase Price Allocation, Net Tangible Assets	4.4
Vela Systems [Member] | Developed Technology Rights [Member]
Business Acquisition [Line Items]
Business Acquisition, Purchase Price Allocation, Amortizable Intangible Assets	5.9
Vela Systems [Member] | Customer Relationships [Member]
Business Acquisition [Line Items]
Business Acquisition, Purchase Price Allocation, Amortizable Intangible Assets	3.6
Vela Systems [Member] | Trade Names [Member]
Business Acquisition [Line Items]
Business Acquisition, Purchase Price Allocation, Amortizable Intangible Assets	$ 2.6

[1] (1)The amount of goodwill expected to be deductible for tax purposes is zero.