Fair Value Measurements (Details) (USD $) In Thousands, except Share data, unless otherwise specified	12 Months Ended																			1 Months Ended
	Dec. 29, 2013	Dec. 30, 2012	Jan. 01, 2012	Dec. 29, 2013 Fair Value, Measurements, Recurring [Member] Fair Value [Member]		Dec. 30, 2012 Fair Value, Measurements, Recurring [Member] Fair Value [Member]		Dec. 29, 2013 Fair Value, Measurements, Recurring [Member] Level 1 [Member]		Dec. 30, 2012 Fair Value, Measurements, Recurring [Member] Level 1 [Member]		Dec. 29, 2013 Fair Value, Measurements, Recurring [Member] Level 2 [Member]		Dec. 30, 2012 Fair Value, Measurements, Recurring [Member] Level 2 [Member]		Dec. 29, 2013 Fair Value, Measurements, Recurring [Member] Level 3 [Member]		Dec. 30, 2012 Fair Value, Measurements, Recurring [Member] Level 3 [Member]		Jun. 30, 2013 TowerJazz [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Money market funds				$ 35,812	[1]	$ 21,907	[1]	$ 35,812	[1]	$ 21,907	[1]	$ 0	[1]	$ 0	[1]	$ 0	[1]	$ 0	[1]
Investment in TowerJazz Semiconductor Ltd.				0	[2]	345	[2]	0	[2]	345	[2]	0	[2]	0	[2]	0	[2]	0	[2]
Total assets				35,812		22,252		35,812		22,252		0		0		0		0
Previously unissued stock by subsidiary or equity investee, shares sold in period																				42,970,000
Gain on sale of previously unissued stock by subsidiary or equity investee																				181,000
Proceeds from sale provided by TowerJazz Semiconductor Ltd. shares	$ 265	$ 0	$ 0																	$ 265,000

[1] Money market funds are presented as a part of cash and cash equivalents on the accompanying consolidated balance sheets as of December 29, 2013 and December 30, 2012.

[2] In June 2013, the Company sold all of its 42,970 remaining shares of TowerJazz marketable securities for a gain of $181,000 and cash proceeds of $265,000.