Segment Information (Narrative) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Jun. 30, 2013	Jun. 30, 2012
Revenue, Major Customer and Geographic Information
Entity Wide Revenue By Major Customer Percent Of Revenue Did Not Exceed Ten Percent	10.00%
Sales Revenue, Goods, Net [Member] | Customer Concentration Risk [Member] | GameStop Corp
Revenue, Major Customer and Geographic Information
Entity Wide Revenue By Major Customer Percent Of Revenue Did Not Exceed Ten Percent	10.00%
Entity Wide Revenue By Major Customer Percent Of Revenue		11.00%
United States [Member]
Revenue, Major Customer and Geographic Information
Disclosure on Geographic Areas, Revenue from External Customers Attributed to Entity's Country of Domicile	99.00%
Switzerland [Member]
Revenue, Major Customer and Geographic Information
Disclosure on Geographic Areas, Revenue from External Customers Attributed to Foreign Countries	$ 403	$ 273
Disclosure on Geographic Areas, Revenue from External Customers Attributed to Foreign Countries, Percentage	43.00%	29.00%