Marketable Securities - Narrative (Details) (Marketable debt securities [Member])	9 Months Ended
	Sep. 28, 2014
Minimum [Member]
Investment [Line Items]
Term of securities, short-term	1 month
Term of securities, long-term	12 months
Maximum [Member]
Investment [Line Items]
Term of securities, short-term	12 months
Term of securities, long-term	36 months