Leases (Schedule of Lease Balance Classifications Within Consolidated Balance Sheets and Lease Activities) (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 28, 2019	Sep. 29, 2018
Operating lease right-of-use assets
Balance as of December 29, 2018	$ 0
Right-of-use assets recorded from adoption of ASC 842	29,893
Right-of-use assets obtained in exchange for new lease obligations during the period	404	$ 0
Amortization of right-of-use asset during the period	(4,372)
Impairment of right-of-use asset on Portland, Oregon office (recorded in Restructuring charges)	(977)	0
Adjustments for present value and foreign currency effects	(385)
Balance as of September 28, 2019	24,563
Operating lease liabilities
Balance as of December 29, 2018	0
Lease liabilities recorded from adoption of ASC 842	32,273
Lease liabilities incurred for new lease obligations during the period	404
Accretion of lease liabilities	1,467
Operating cash used by payments on lease liabilities	(6,540)	$ 0
Adjustments for present value, foreign currency, and restructuring liability effects	(497)
Balance as of September 28, 2019	27,107
Less: Current portion of operating lease liabilities	4,623
Long-term operating lease liabilities, net of current portion	$ 22,484