Stock-Based Compensation - Weighted Average Fair Value (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 29, 2020	Oct. 01, 2019	Sep. 29, 2020	Oct. 01, 2019	Dec. 31, 2019
Stock Options
Stock option activity, Shares
Outstanding at beginning of year (in shares)			1,829
Granted (in shares)			654
Exercised (in shares)	0		(4)
Forfeited or cancelled (in shares)			(118)
Outstanding at end of the period (in shares)	2,361		2,361		1,829
Exercisable at end of the period (in shares)	1,188		1,188
Weighted Average Exercise Price
Outstanding at beginning of year (in dollars per share)			$ 47.32
Granted (in dollars per share)			40.16
Exercised (in dollars per share)			29.79
Forfeited or cancelled (in dollars per share)			47.15
Outstanding at end of the period (in dollars per share)	$ 45.38		45.38		$ 47.32
Exercisable at end of the period (in dollars per share)	$ 46.74		$ 46.74
Weighted Average Remaining Contractual Term (In years)
Weighted Average Remaining Contractual Term (In years)			5 years 1 month 6 days		4 years 3 months 18 days
Exercisable at end of the period (In years)			2 years 6 months
Aggregate Intrinsic Value
Outstanding at beginning of year			$ 844
Outstanding at end of the period	$ 8,701		8,701		$ 844
Exercisable at end of the period	$ 4,986		4,986
Shares issued during the period	0	0
Total intrinsic value of options exercised		$ 100	35,606	$ 3,700
Unrecognized Stock-based Compensation Expense
Total unrecognized stock-based compensation expenses related to unvested stock options, restricted shares and restricted share units	$ 7,500		$ 7,500
Expected weighted average period for recognition of compensation expense related to unvested stock option			3 years 7 months 6 days
Restricted Shares and Restricted Share Units
Restricted Shares and Restricted Share Units, Shares
Outstanding at beginning of year (in shares)			1,764
Granted (in shares)			588
Vested (in shares)			(285)
Forfeited (in shares)			(182)
Outstanding at end of the period (in shares)	1,885		1,885		1,764
Fair value of shares vested	$ 1,800	$ 1,900	$ 14,200	$ 14,300
Weighted Average Fair Value
Outstanding at beginning of year (in dollars per share)			$ 47.76
Granted (in dollars per share)	$ 24.00	$ 44.24	39.74
Vested (in dollars per share)			49.94
Forfeited (in dollars per share)			49.13
Outstanding at end of the period (in dollars per share)	$ 44.79		$ 44.79		$ 47.76
Unrecognized Stock-based Compensation Expense
Total unrecognized stock-based compensation expenses related to unvested stock options, restricted shares and restricted share units	$ 34,300		$ 34,300
Expected weighted average period for recognition of compensation expense related to unvested stock option			3 years