Subsequent Events Subsequent Events (Details) (Acquisition [Member], SMSC Acquisition [Member], USD $)	2 Months Ended
	May 30, 2012	May 02, 2012
Acquisition [Member] | SMSC Acquisition [Member]
Subsequent Event [Line Items]
Subsequent Event, Date	May 02, 2012
Price for share business acquisition agreement	$ 37.00
Total expected equity value of business acquisition at close		$ 939,000,000
Total expected enterprise value of business acquisition at close		766,000,000
Total cash and investment of acquired company expected at close		$ 173,000,000