Leases (Schedule of Lease Balance Classifications Within Consolidated Balance Sheets and Lease Activities) (Details) - USD ($) $ in Thousands	6 Months Ended
	Jun. 29, 2019	Jun. 30, 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	298	$ 0
Amortization of right-of-use asset during the period	(2,907)
Impairment of right-of-use asset on Portland, Oregon office (recorded in Restructuring charges)	(977)	0
Adjustments for present value and foreign currency effects	(215)
Balance as of June 29, 2019	26,092
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	298
Accretion of lease liabilities	999
Operating cash used by payments on lease liabilities	(4,613)	$ 0
Adjustments for present value, foreign currency, and restructuring liability effects	(361)
Balance as of June 29, 2019	28,596
Less: Current portion of operating lease liabilities	4,804
Long-term operating lease liabilities, net of current portion	$ 23,792