Fair Value Measurements (Tables)

9 Months Ended

Sep. 26, 2015

Fair Value Measurements [Abstract]

Financial Assets Measured At Fair Value On Recurring Basis

	Fair value,
	September 26, 2015
(in thousands)	Level 1		Level 2
Assets:
Money market funds	$	4,040	$	—
Corporate bonds and notes		97,434		21,224
U.S. treasury and government agency notes		46,835		—
Foreign government and agency notes		1,509		9,514
U.S. state and municipal securities		151		80
Total assets	$	149,969	$	30,818
	Fair value,
	December 27, 2014
(in thousands)	Level 1		Level 2
Assets:
Money market funds	$	8,729	$	—
Corporate bonds and notes		88,401		17,030
U.S. treasury and government agency notes		38,283		1,387
Foreign government and agency notes		537		7,525
U.S. state and municipal securities		—		231
Total assets	$	135,950	$	26,173
These assets are included in Cash and cash equivalents, Short-term investments, and Long-term investment securities.  See Note 7. Investment Securities.

Financial Liabilities Measured At Fair Value On Recurring Basis

	Fair value,
	September 26, 2015
(in thousands)	Level 2
Current liabilities:
Forward currency contracts	$	2,744
	Fair value,
	December 27, 2014
(in thousands)	Level 2
Current liabilities:
Forward currency contracts	$	1,907
These are included in Accrued liabilities.