Restructuring Charges (Details) (USD $) In Thousands, unless otherwise specified	6 Months Ended
	Jun. 28, 2014	Jun. 29, 2013
Restructuring reserve balance
Balance at the beginning of the period		$ 2,979
Amounts paid, net of amounts received		(1,167)
Adjustments and effect of foreign currency translation		(321)
Balance at the end of the period		1,491
Current portion of deferred rent
Restructuring reserve balance
Balance at the end of the period	700
Office Vacancies
Restructuring reserve balance
Balance at the beginning of the period	1,170	2,106
Amounts paid, net of amounts received	(452)	(451)
Adjustments and effect of foreign currency translation	20	(177)
Balance at the end of the period	738	1,478
Employee Workforce Reduction
Restructuring reserve balance
Balance at the beginning of the period		873
Amounts paid, net of amounts received		(716)
Adjustments and effect of foreign currency translation		(144)
Balance at the end of the period		$ 13